ESP-P-6000

GAS Y PETROQUIMICA BASICA

GERENCIA DE PROYECTO Y CONSTRUCCIÓN

SUBGERENCIA DE SERVICIOS TÉCNICOS

PROYECTO: Q-600-64-03

OBRA: “CONSTRUCCIÓN DE DOS PLANTAS

CRIOGÉNICAS MODULARES Y TERMINAL DE RECIBO Y DISTRIBUCIÓN DE GAS LP Y GASOLINAS EN LA ESTACION 19, AREA DE REYNOSA, TAMPS.”

LUGAR: REYNOSA, TAMAULIPAS

ESP-P-6000, Rev. 2 SPECIFICATION OF

GENERAL INSTRUMENTATION

No. ESP-P-6000

REV. 2

GAS Y PETROQUÍMICA BÁSICA



SPECIFICATION INSTRUMENTATION

Date: Jun -2001

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“En PGPB la más alta prioridad es la seguridad de nuestros trabajadores, nuestros clientes, nuestros vecinos y el medio ambiente”

Rev 0 Por Gerencia de Proyecto y Construcción Fecha 21 Feb 00

Rev 1 Por Gerencia de Proyecto y Construcción Fecha 21 Nov 00

Rev 2 Por Gerencia de Proyecto y Construcció Fecha 21 Jun 01

Rev Por Fecha

Rev Por Fecha

X

Versión nueva

Cambios en alguna página

Versión reeditada completamente

Preparada por: Pemex Gas y Petroquímica Básica

Fecha: 21 - noviembre - 2000.

Por Gerencia de Proyecto y Construcción

Realizó: BNC

Especialista Instrumentación:

Revisó: GZC

Subgerente de Servicios Técnicos

Vo. Bo. MLF

Director de Proyecto

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“En PGPB la más alta prioridad es la seguridad de nuestros trabajadores, nuestros clientes, nuestros vecinos y el medio ambiente”

TABLE OF CONTENTS

SECTION PAGE

1. 0 SCOPE............................................................................................................................... 4

2. 0 CODES AND STANDARDS........................................................................................... 4

3. 0 GENERAL ......................................................................................................................... 8

4. 0 STANDARD PRACTICE ...............................................................................................14

5. 0 INSTALLATION..............................................................................................................47

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“En PGPB la más alta prioridad es la seguridad de nuestros trabajadores,

nuestros clientes, nuestros vecinos y el medio ambiente”

1.0 SCOPE

This specification prescribes the design standards and engineering practices to be used to instrument and control two Modular Cryogenic Plants and L.P.G. & Natural Gasoline receipt and distribution Terminal in Reynosa, Tamps. Mexico. These design standards and engineering practices shall be strictly followed.

The operating philosophy for two Modulars Criogenics Plants Construction and Distribution and Recieve Terminal of L.P.G. and Naturals Gasoline in the 19 Station in Reynosa, Tamps. is to monitor and control the plant along with auxiliary/utilities systems from one central control room using CRT based consoles.

2.0 CODES AND STANDARDS

2.1 The design, equipment, material and installation shall conform to the requirements of the following applicable documents:

2.1.1ANSI (National Standards Institute)

MC 96.1 Temperature Measurement Thermocouples.

2.1.2API (American Petroleum Institute)

API MPMS14.3 Manual of Petroleum Measurement Standards, Chapter 14, Section 3, "Orifice Metering of Natural Gas and Other Related Hydrocarbon Fluids" (AGA Report No. 3, ANSI/API 2530)

API RP 520 Sizing, Selection, and Installation of Pressure-Relieving Devices in Refineries

API RP 521 Guide for Pressure-Relieving and Depressuring Systems

API RP 526 Flanged Steel Safety-Relief Valves

API RP 527 Commercial Seat Tightness of Safety Relief Valves with Metal-to-Metal Seats

API RP 550 Manual on installation of refinery instruments and control systems.

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API Std. 598 Valve Inspection and Test

API Std. 2000 Venting Atmospheric and Low-Pressure Storage Tanks

API Std. 2530 Manual of Petroleum Measurement Standards, Chapter 14 - Natural Gas Fluids Measurement, Section 3, Orifice Metering Of Natural Gas and Other Related Hydrocarbon Fluids

2.1.3 ASME (American Society of Mechanical Engineers)

ASME Boiler and Pressure Vessel Code, Section I - Power Boilers

ASME Boiler and Pressure Vessel Code, Section VIII - Pressure Vessels

ASME B1.20 Pipe Threads, General Purpose (Inch)

ASME B16.5 Pipe Flanges and Flanged Fittings

ASME B31.1 Code for Pressure Piping, Power Piping

ASME B31.3 Code for Pressure Piping, Chemical Plant and Petroleum Refinery Piping

2.1.4 ASTM (American Society for Testing and Materials)

ASTM E230 Standard Temperature EMF (Electromotive Force) Tables for Standardized Thermocouples

2.1.5 CFR (Code of Federal Regulations)

29 CFR1910.95 Part 1910 OSHA (Occupational Safety and Health) Standards, Subpart G, Occupational Health and Environmental Control, Section 95, Occupational Noise Exposure.

29 CFR1910.119 Process Safety Management of Highly Hazardous Chemical.

2.1.6 FCI (Fluid Controls Institute, Inc.)

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FCI 70-2 American National Standard for Control Valve Seat Leakage (formerly ANSI B16.104)

FCI 84-1 Metric Definition of the Valve Flow Coefficient C(v)

2.1.7 ISA (Instrument Society of America)

ISA MC96.1 Temperature Measurement Thermocouples (ANSI MC96.1)

ISA S5.1 Instrument Symbols and Identification

ISA S5.2 Binary Logic Diagrams for Process Operations

ISA S5.3 Graphic Symbols for Distributed Control/Shared Display Instrumentation, Logic and Computer Systems

ISA S5.4 Instrument Loop Diagrams

ISA S7.3 Quality Standard for instrument air

ISA S18.1 Annunciator Sequences and Specifications

ISA S20 Specification Forms for Process Measurement and Control Instruments Primary Elements and Control Valves

ISA S75.01 Flow Equations for Sizing Control Valves

ISA S75.03 Face-to-Face Dimensions for Flanged Globe-Style Control Valve Bodies

ISA S75.04 Face-to-Face Dimensions for Flangeless Control Valves

ISA S75.16 Face-to-Face Dimensions for Flanged Globe-Style Control Valve Bodies (ANSI classes 900, 1500 and 2500)

ISA RP 3.2 Flange mounted sharp edged orifice plates for flow measurement.

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ISA RP75.17 Control Valve Aerodynamic Noise Prediction

ISA S75.22 Face-to-Centerline Dimensions for Flanged Globe-Style Angle Control Valve Bodies

ISA S84.01 Application of Safety Instrumented System for the Process Industries.

2.1.8 IEC (International Electrotechnical Commission)

IEC 61508 Functional Safety: Safety-Related-System.

2.1.9 NEMA (National Electrical Manufacturers Association)

ICS 6 Industrial control and systems enclosures

NEMA SM 23 Steam Turbines for Mechanical Drive Service

2.1.10 NFPA (National Fire Protection Association)

NFPA 79 Electrical Standard for Industrial Machinery

NFPA 70 National Electrical Code

NFPA 496 Purged Enclosures for Electrical Equipment

NFPA 8502 Standard for the Prevention of Furnace Explosion/Implosion in multiple boilers

2.1.11 Reference Specifications

A-001 General notes, legend and symbols ESP-P-6120, 6770, 6810 Level instruments ESP-P-6700 Control Systems/Instrumentation Philosophy ESP-P-6701 Integracion de Sistemas de Control ESP-P-6730 Programmable Logic Controller ESP-P-6740 Safety Instrument System ESP-P-6750 Sistema de Control Red Contra Incendio ESP-P-6760 Instruments Furnished with Packaged Equipment ESP-P-6880 Uninterruptible Power Supply ESP-P-6920 Instrument Installation Material ESP-P 6940 Instrument Piping and Wiring Installation ESP-A-1170 Spare part requirements

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2.2 Quality Assurance

2.2.1 Test Certification

Instrument hardware furnished for the project shall be test certified by one of the following:

UL (Underwriters Laboratories) FM (Factory Mutual Engineering Corporation)

3.0 GENERAL

3.1 General Practice

3.1.1 The selection and application of instrument systems shall be determined by analysis of the process involved and the required measurements and controls, in accordance with P&ID (Piping and Instrument Diagrams) elaborate by the Contract.

3.1.2 P&ID symbols and nomenclature for instruments are derived from the ISA Standard S5.1 entitled "Instrument Symbols and Identification" and ISA Standard S5.3 entitled "Graphic Symbols for Distributed Control/Shared Display Instrumentation, Logic and Computer Systems."

3.1.3 Logic or state diagrams shall be used in all cases where interlock or shutdown functions are involved, if these cannot easily be shown on the P&IDs. Logic diagrams shall generally conform to ISA Standard 5.2, entitled "Binary Logic Diagrams for Process Operations."

3.1.4 An instrument shall not be used for both control service and safeguarding service.

3.1.5 Where possible, direct process switches (connected to SCD, SCI, PLC, or SIS) shall be replaced by transmitters.

3.1.6 Electronic instruments shall be used to the extent possible. Smart transmitters shall be used where available and where fast speed of response is not required. Pneumatic instruments shall be used only where electronic instruments (transducers, positioners and solenoid valves) are not practical.

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3.1.7 Instrument analog signals for electronic instrument systems shall be 4 to 20 mA DC. Instrument analog signals for pneumatic instrument systems shall be 0.2 to 1.0 kg/cm2 G.

3.1.8 The major equipment manufacturer in accordance with the specifications shall furnish instrumentation for major equipment package units such as compressors and drivers. Instruments furnished as part of major equipment package units shall be identified and tagged on the flow sheets and entered on the Instrument Index. The types of instruments furnished, as part of these package units shall be consistent with that furnished for the project. Instruments shall conform to Specification ESP-P-6760 Instruments Furnished with Packaged Equipment.

3.1.9 Instrument systems quality and types furnished shall normally be the manufacturer's standard which satisfies the requirements of applicable instrument specifications issued for this project.

3.1.10 Specifications shall normally be prepared for each device for which the contractor has direct procurement or engineering design responsibility.

3.1.11 Specification forms shall covers information generally covered under ISA S20.

3.1.12 Instrument quantities shall be furnished as indicated on the P&IDs approved for the project. A complete index of all instruments shall be furnished. The index report shall contain fields, which reference pertinent engineering documents.

3.1.13 The instrument index shall be developed using Instrument Loop Generation (ILG).

3.1.14 Instrument Nameplates: Permanent type instrument nameplates, firmly fastened, shall be furnished with all major instrument equipment. Each nameplate for field instruments and rear of panel instruments shall carry the tag number only, shall be made of stainless steel, and shall be attached to the instrument with stainless steel wire. Nameplates for instruments mounted on front of a panel shall be engraved with the instrument tag number, service and any multiplication factor, if any.

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3.2 Numbering Systems

3.2.1 Instrument Identification

a.Instrument symbols on Piping and Instrument Diagrams shall be according to ISA S5.1 and ISA S5.3.

b.Instrument tag numbers and loop numbers shall be assigned according to the project numbering system.

Instrument tag number: unit-instrument function-three digit sequence number

Example: Instrument 21-TIC-678, for Temperature Indicating Controller in unit 21 with a sequence number 678.

Loop number: unit-loop function-three digit sequence number

Example: Loop 21-T-678 for temperature loop in unit 21 with a sequence number 678.

Same sequence number can be used for loops with different functions (example: 21-T-678 and 21-P-678). The sequence numbers shall not be suffixed (example: 21-TIC-678A) to the extent practical. If more than one instrument on a loop has same ISA identification (example: TI), the SCD instrument tag number should not be suffixed and the panel and field instrument tag numbers should be suffixed (example: 21-TI-678 on SCD and 21-TI-678A on local panel).

c.Each control system loop shall have a unique numerical designation for categories of pressure, temperature, flow, level and miscellaneous (parallel system). If an instrument is common to 2 loops, it may have its own number or be numbered as part of one of the loops.

d.All instruments furnished by equipment suppliers with major engineered equipment shall have tag numbers assigned by the contractor according to the project numbering system (refer to Section 3.2.1.b).

3.2.2 Instrument Specification Sheets

Instrument Specification sheets shall be numbered according to ISA S20. The system consists of 4 parts:

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Unit number - Instrument group . group sequence . sheet number. The following example illustrate the numbering system.

Pressure transmitter (electronic) 21-PT-345 falls in unit 21, is a group 3 type (pressure instrument), belongs to group sequence 01 (pressure transmitter - electronic), and the specification sheet is the second within the group and sequence for that area.

Progressive sheet number(001-999).

Group Sequence number

ISA Group Number (PressureInstrument)

Unit Number

EXAMPLE: 21 - 03.01.002

3.3 Units of Measurement

3.3.1 The following units of measurement shall be used in the process measurement and control instrumentation and calculations:

Temperature: Degrees Celsius (°C)

Pressure: Kilograms per square centimeter Gauge (kg/cm2 G)

Millimeter of water (w.c.)

Kilograms per square centimeter absolute (kg/cm2 A)

Kilograms per square centimeter differential (kg/cm2)

Level:

General Percent (%)

Tank Gage Millimeters

Flow, Volumetric units:

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Process Liquid Cubic meter per hour at 15 degrees C (m3/hr) and barrels per day at 60° F (BPSD) in parentheses

Chemical Liters per hour (lph)

Water Cubic meters per hour at 15° C (m3/hr) or Liters per minute (lpm)

Gases / Vapors Normal cubic meters per hour at 0° C (Nm3/hr) and standard cubic feet per day at 68° F (SCFD) in parentheses

Flow, Mass units:

Process Kilograms per hour (kg/hr)

Steam & Boiler Kilograms per hour (kg/hr) Feedwater

3.3.2 The flow measurements for hydrocarbons shall also be provided in English units on the instrument data sheets. The English units shall be placed within parentheses. Example: 100,000 Nm3/hr (94 MMSCFD)

3.3.3 All CRT based numerical displays and instrument charts and scales shall be calibrated as follows:

Temperature: Direct reading Pressure: Direct reading Level: 0 to 100 percent uniform Flow: Direct reading

3.3.4 Local indicator scales shall be metric unit. Dual scales in metric and English units are acceptable. Scales shall be calibrated as follows:

Temperature: Direct reading Pressure: Direct reading Level: Direct reading or 0 to 100 percent linear Flow: Direct reading, or 0 - 10 linear, or 0 - 10 square root.

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3.4 Design Requirements

3.4.1 Instrument air is provided at design pressure of 10.5 kg/cm2 G, maximum pressure of 8.8 kg/cm2 G, normal pressure of 7 kg/cm2 G, and minimum pressure of 4.2 kg/cm2 G.

3.4.2 Field mounted (but not located in-line or on-vessel) instruments shall normally have wall/yoke mounting cases.

3.4.3 Electrical

a. Enclosures for electrical instruments and junction boxes shall comply with requirements of the electrical area classification in which they are installed. In the event that the manufacturer of certain instruments cannot provide enclosures suitable for the area, purging of the enclosure with inert, dry air or gas, according to NFPA 496, shall be given consideration. Cases for locally mounted instruments and devices shall be weatherproof, conforming to NEMA 4X requirements as a minimum.

b. Terminals for electrical interconnections including thermocouple wire shall be clearly identified as required to indicate polarity, electrical ground where applicable, and test connection. Terminals for purchased items shall normally be identified according to manufacturer's standard marking.

c. Wiring for different signal types shall not share the same cables, terminal boxes, tray section, or conduit. The following systems shall be separated from each other and from other power circuits in the facility. Fiber optic cable may be installed along with any other wiring system.

1. Milliamp electronic instrument and RTD signals. 2. Thermocouple extension wire. 3. Turbine meter and other pulsed DC signals. 4. AC (Alternating Current) or DC (Direct Current) alarm,

shutdown, status indication, remote motor control, solenoid, and power circuits to field instruments of the same nominal voltage.

5. Digital data bus or highway for distributed control systems, computers, programmable logic controllers, or multiplexers.

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d. Electrical conduit connections for locally mounted instruments shall normally be internally threaded, where available as manufacturer's standard option. Connections shall be suitable for the electrical area classification in which the instrument is installed.

e. Tropicalization of electronic instrument circuitry is required.

f. Thermocouple extension wire to the process area junction boxes shall normally be multiconductor cable with individual twisted and shielded pairs of 20-gage solid wire and an overall aluminized mylar shield. Single pair twisted, shielded, solid 16-gage lead wire shall be routed in conduit from the junction box terminal blocks to the thermocouple assembly. Where thermocouples are for inputs to high speed multiplexers, computer and logger installations, they shall be individually shielded pairs. Extension wire shall be color coded according to ANSI standard MC96.1.

4.0 STANDARD PRACTICE

4.1 Temperature Instruments

4.1.1 Electronic Temperature Transmitters shall be used for control and equipment/unit shutdown applications and are optional for monitoring applications. Transmitter shall detect open circuit in the temperature element wiring and fail upscale or downscale as required by the process application. Transmitter output shall be 4-20 mA DC linear with the temperature being measured. Transmitter shall provide ambient temperature compensation.

4.2 Thermowells, Thermocouples And Thermometers

4.2.1 Temperature Wells shall be used for all temperature elements and temperature test services except for motor winding and tube skin applications.

a. Construction shall be 0.260 inch bore designed to fit a 1/4 inch OD element.

b. Material shall be type 304L stainless steel well and screwed wells unless other material is required by piping specifications. Wells shall be tapered and highly polished

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and hydrostatically tested to 281 kg/cm2 G minimum at ambient temperature.

c. Well Connections Mating flanges shall be stainless steel, unless temperature considerations require other materials.

d. Thermowell Extensions shall be provided when required to extend beyond insulation.

e. Special Protecting Tubes of chrome iron, incoloy, or other special materials shall be used as required for fire boxes, kilns, reactors and oxidizing atmospheres.

f. Plastic Plugs for internal thread protection shall be furnished with all wells.

g. Identification of thermowells shall be by a stamped code number indicating material and nominal "U" dimension.

4.2.2 Thermocouples shall be magnesium-oxide insulated and sheathed type. Sheath shall be 1/4 inch diameter type 316 stainless steel. The hot junction shall be ungrounded to the sheath. The element shall be furnished with a sealed transition and 1000 mm of armored and plastic covered stranded lead wire or complete thermocouple assembly.

a. Type "K" chromel-alumel thermocouples shall be used for temperature ranges within 0 to 1150 ºC. Type "B" platinum 30% rhodium-platinum 6% rhodium thermocouples shall be used for temperatures above 1350 ºC. Type "T" copper-constantan thermocouples shall be used for temperature ranges -130 to 350 ºC. Type “J” iron-constantan thermocouples shall be used for temperature ranges 0 to 600 °C. Type “E” chrome-constantan thermocouples shall be used for temperature ranges 0 to 800 °C.

b. Thermo-Electric Properties and Limits of Error of Thermocouples shall conform to ANSI MC96.1, Temperature Measurement Thermocouples.

c. Refer to Section 3.4.3.f for thermocouple wiring.

d. Identification of Thermocouple Assemblies shall be by attaching a name-plate showing tag number to the head.

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e. Thermocouple Heads shall be mounted on the end of a 3/4 inch conduit run close to the thermocouple.

4.2.3 Resistance Temperature Detectors (RTDs) shall be considered for applications where very narrow spans and high accuracy are required. RTDs shall be 3-wire, Pt-100, 1/4 inch stainless steel sheath type.

4.2.4 Installation and insertion depth of thermocouples, assemblies, and test wells shall be in accordance with ISA Standards.

4.2.5 Thermometers shall be bimetallic sealed type, non-reset, heavy duty, back connected adjustable every angle type with 125 mm (5”) minimum diameter dial. Dials of 75 mm (3”) diameter shall be used in mechanical equipment lube and seal oil service or other auxiliary service.

4.2.6 Temperature elements shall be procured with temperature wells to assure proper fit.

4.3 Pressure Transmitters

Pressure transmitters shall be used where indication and/or record of pressure is required at a location not adjacent to the primary element. All range of operation shall be between 50 – 75 % of their scale and shall have local indication.

4.3.1 Absolute Pressure Transmitters shall provide barometric pressure compensation.

4.3.2 Pressure Transmitters for suppressed range control shall be non-indicating force balance, variable capacitance.

4.3.3 Pressure Elements shall be ANSI type 316 stainless steel except where the process requires a special material.

4.3.4 Connections for pressure transmitters shall be 1/2 inch NPT.

4.4 Pressure Gauges

4.4.1 Range shall be specified such that the gauge normally operates in the middle third of the scale. Gauge ranges on pump discharges shall be specified for overrange protection beyond the pump shut in pressure or relief valve setting. Gauge ranges on

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vessels shall be specified for overrange protection not less than 1.2 times the vessel design pressure.

4.4.2 Accuracy of all direct connected gauges in process service shall be guaranteed for at least ±1/2 of 1% of maximum scale reading over the entire scale.

4.4.3 Pressure Elements shall be 316 stainless steel, including tube, socket and tip except where the process requires a special material. Elements above 66.7 kg/cm2 G shall be bored instead of drawn and connections to socket and tip shall be threaded and backwelded.

4.4.4 Pressure Gauge Movements shall be hardened stainless steel or hardened monel for stainless steel bourdon tubes.

4.4.5 Sockets and Tips shall be steel for stainless steel bourdon tubes.

4.4.6 Over-Pressure Protection shall be 1.3 times the maximum tube rating to prevent permanent set from continuous overpressures. Wide bourdon tubes, such as used for 4.22 kg/cm2 G and below which do not inherently have the above characteristic, shall be furnished with overload stops to provide this protection.

4.4.7 Blow Out Protection shall be provided on all gauges in process service connected directly to the pressure source. When required, rupture discs or blow out plugs shall be installed on the lower side of the case for local mounted gauges and on the case back for board mounted gauges.

4.4.8 Weep Holes shall be provided on the case bottom of all gauges located in humid areas unless the case already has sufficient ventilation.

4.4.9 Pulsating Service installations shall be provided with pulsation dampeners.

4.4.10 Diaphragm Protectors shall be used where necessary to protect gauges from corrosive fluids, from freezing or evaporation of process fluid. They shall have one inch NPT screwed or flanged connections in accordance with piping specifications and shall be identified by a symbol on the engineering flow sheets.

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4.4.11 Pigtails or Siphons shall be provided on hot vapor service and all steam service to prevent the heat from contacting the bourdon tube. For highly viscous materials, special precautions must be taken.

4.4.12 Cases for gauges in the process area shall be solid front phenolic turret type with a snap ring. Cases shall be weatherproof and metal cases shall be protected with weather-resistant black paint.

4.4.13 Pressure Gauge Case Sizes shall be:

Local Mounted 115 mm (4.5”) Local Panel Mounted 115 mm (4.5”) Transmitters 90 mm (3.5”) Valve Actuators 40 mm to 60 mm (1.5” to 2.5”) Special Applications 150 mm (6”)

4.4.14 Dials shall be white, non-rusting metal or plastic, with black figures.

Manufacturer's standard dial faces shall be marked with the words, "Steel Tube", etc. This does not apply to 40 mm (1.5”) and 50 mm (2”) gauges. Pointers shall have micrometer adjustment.

4.4.15 Connections for 115 mm (4.5”) pressure gauges, process take-off connections, and first block valve shall be 3/4 inch NPT. After first block valve, piping and valve may be reduced to 1/2 inch NPT. Receiver gauges and 60 mm (2.5”) pressure gauges may be 1/4 inch NPT.

4.4.16 Receiver Gauge Elements shall be calibrated to read zero at 0.2 kg/cm2 G and full scale at 1 kg/cm2 G. Receiver dials shall be graduated to match the range of the transmitter.

4.5 Flow Transmitters

4.5.1 Differential Pressure type instruments shall be a prime choice for flow measurements.

4.5.2 Electronic Flow Transmitters shall be the force balance differential converter type (variable capacitance or strain gage to sense force). Bodies shall be carbon steel with stainless steel internal trim, unless other materials are required for the particular

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service. Overrange protection equal to the body rating shall be provided.

4.5.3 Differential Pressure Indicators shall be normally bellows type 150 mm (6”) dial locally mounted on a 2” pipe stand. Connections shall be 1/2 inch NPT with 1/4 inch NPT Vent/Drain. Element material shall be 316 L SS minimum with carbon steel chamber. Minimum pressure rating shall be 35 kg/cm2 G. It shall be able withstand maximum relieving pressure of the system.

4.5.4 Mass flow and density sensor/transmitters shall be used to precision measurement of volumetric flow rate in loading trucks. Sensor shall operate by coriolis principle. Sensor and explosion-proof transmitter shall be installed in the same hazardous area.

4.6 Primary Flow Devices

4.6.1 Orifice Plates of the square edged concentric type shall be specified except where they are unsatisfactory for the application. Plate dimensions shall conform to API STD 2530, latest edition. Materials shall be ANSI type 316 stainless steel unless special materials are required for the service. For special application shall provide double chamber orifice fittings.

4.6.2 Differential Pressure Range shall preferably be 2500 mm water column. A higher differential may be used when the primary flow element is in series with a control valve and there is no increase in the system energy loss. Differential pressure range for gas or vapor shall normally not exceed 400 mm of water for each kg/cm2 A inlet pressure.

4.6.3 The d/D Ratio shall be around 0.63

4.6.4 Orifice Run Design shall be in accordance with API STD 2530. Runs shall normally be sized for a d/D of 0.75.

4.6.5 Orifice Bores shall be calculated by formula based on API STD 2530 latest edition. Maximum flow rate shall be chosen so that a rounded factor is available.

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4.6.6 Flange Taps shall be used in accordance with the latest edition API STD 2530/ASME recommendations. 1/2 inch NPT tap size shall be specified for up to ANSI 600# line classification. 3/4 inch NPT tap size shall be specified for ANSI 900# and ANSI 1500# line classifications.

4.6.7 The Minimum Orifice Flange Rating shall be 300# ANSI. The use of higher rated flanges, or of facing other than raised face shall be as called for in piping specifications.

4.6.8 Ring Type Plate Holders shall be manufacturer's standard plate mounting. Ring facing shall be oval ANSI standard unless otherwise required by piping specifications.

4.6.9 Orifice Taps for horizontal pipe runs shall be oriented horizontal for clean liquids and steam, and vertical-up for gases (preferred). Alternately, orifice taps may be 45° below the horizontal centerline for clean liquids and steam, and 45° above the horizontal centerline for gases.

4.6.10 Venturi Tubes, Low Loss Flow Tubes and Flow Nozzles shall be used where high pressure recovery is necessary and/or where only a low inlet pressure is available.

4.6.11 Pitot and Pitot Venturi Elements shall be used where high accuracy is not required, or the pipe diameter is too large for acceptable orifice plate design.

4.6.12 Variable Area flow meters shall be used for small flow rates where local indication, recording or control is required. They may also be used where rangeability, nonlinearity, viscosity or the hazardous nature of the fluid makes the differential pressure-type instrument unsatisfactory. They shall be armored type with a magnetic pick-up.

4.6.13 Positive Displacement Meters or turbine meters shall be used to measure flows where the integrated flowing quantity with a high accuracy is desired.

4.6.14 Other Types of Flow Elements should be considered where the above mentioned elements are not acceptable.

4.6.15 Meter Run Piping for sharp edged orifice plates shall be furnished as part of the piping systems and shall be purchased

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from the pipe shop contractor directly from the piping spool sheets. The meter runs shall be defined and identified on engineering flow sheets and piping spool sheets as follows (the "Meter Run Standard" shall normally be furnished):

a. "Meter Run Standard" shall mean that the upstream and downstream pipe tolerances between the orifice plate and the nearest upstream and downstream fittings shall be standard mill run pipe and shall be smooth and free from blisters and scale. The orifice flange bore shall be machined to the same bore as the pipe. These runs shall not be specially identified on the flow sheets or the piping spool sheets.

b. "Meter Run Certified" shall mean that the upstream and downstream pipe tolerances between the orifice plate and the nearest upstream and downstream fittings shall be selected and fabricated in accordance with the tolerances and practices as recommended by the API STD 2530. The orifice flange bore shall be machined to the same bore as the pipe. These runs shall be identified on the piping spool sheets as "METER RUN CERTIFIED" and shall be identified on the engineering flow assembly. The maximum percent allowable tolerance measured inside and the published inside diameter shall be 0.05% based on a d/D of 0.63.

c. The contractor shall supply Meter Tubes Dimensional Data Sheets filled out, which will constitute the certification. These will be returned to the design engineer for approval before shipment.

d. "Meter Run Calibrated" shall mean that these meter runs will not be furnished by the pipe contractor but may be furnished for installation in a piping system by the contractor. These meter runs are normally for 1-1/2 inch and under pipe sizes and utilize corner taps. The specifications for these meter runs, when required, will be found elsewhere and will mean that they have been flow calibrated in a flow laboratory. These meter runs will be shown on the engineering flow sheets as "API-CAL" adjacent to the symbol for the orifice flange assembly.

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They will show on the piping spool sheets as "METER RUN CALIBRATED".

e. Meter Runs shall be furnished with bolts, nuts, gaskets, jack screws, and hex head pipe plugs in the orifice flange taps, and shall be in accordance with the applicable piping specification.

f. Both Sides of the meter run shall have identical inside diameter. The orifice flanges shall be bored to the same I.D. as the pipe.

4.7 Level Instruments

4.7.1 Magnetic Level Indicators/Transmitters are preferred for indication and control applications where they can be used and are cost-effective. Generally, they can be used for temperature range of -180° to +400° C, pressures up to 900# ANSI class, measurement heights up to 6500 mm and Sp. Gr. higher than 0.3. The indicators can be follower (shuttle) type or flipper (bargraph) type. The flipper type magnetic level indicators shall provide correct level indication under adverse conditions of vibration and turbulence (i.e., the flippers should not change colors under the adverse conditions).

a. Material of construction for chamber and float shall be 316L SS minimum.

b. The sensor wire of the transmitter may be installed in the inner tube of the chamber or outside the chamber.

c. Connections of magnetic level gauges shall be 2" flanged and flange rating shall meet vessel trim specification.

d. Drain and vent valves shall be included with the gauges.

e. Frost-proof extensions shall be provided on the indicators for cryogenic applications.

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4.7.2 External Displacement type instruments shall be used for emergency shutdown service and liquid-liquid interface service.

a. Body Material shall be fabricated carbon steel, with stainless steel displacer and inconel torque tube. Where vessels are of alloy construction, body material shall be of equivalent or better materials.

b. Extension Tubes shall be used above 260 οC and below 0 οC.

c. Connections shall be 2 inch flanges with bottom-bottom and topside connections. Pressure rating shall meet vessel trim.

d. Rotatable Heads shall be specified.

4.7.3 Differential pressure type instruments may be used for ranges above 1200 mm..

4.7.4 Direct Operated type level controls (Ball Float, Mechanically Linked Valve, etc.) shall be used on utility services only.

4.7.5 Continuous level transmitter RF/admittance type shall be used to water vessel, the process wetted parts shall be 316 stainless steel.

4.8 Level Indicators

4.8.1 A gauge glass is not required where a magnetic level indicator/transmitter (refer to Section 4.7.1) is used. If a magnetic level indicator can not be used due to process requirements, a level gauge glass and other level indicators should be considered. Follow Sections 4.8.3 through 4.8.12 shall be followed when level glasses are used.

4.8.2 Liquid level bridle shall be used to minimize the number of vessel nozzles where numerous level instrument connections are made to the same vessel. The top and bottom connections of the bridle shall be directly connected to the vessel independent from any inlet or outlet process nozzle. Bridle connection on vessel shall be 3-inch. Level instruments for shutdown functions shall not be installed on bridles.

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4.8.3 Reflex Type Gauge Glasses shall be used where a liquid-gas interface exists and the liquid is clean, colorless, with a liquid specific gravity above 0.55 and the liquid will not leave deposits on the glass.

4.8.4 Transparent Thru-Vision Gauge Glasses shall be used in all cases where a liquid-liquid interface exists, on liquid gravities of 0.55 or lower, on services involving acid, caustic or dark-colored materials, on heavy and viscous oil service, and on steam generating equipment.

4.8.5 Large Chamber Glasses shall be used where operating temperatures are below ambient and the liquid is near its bubble point. Glasses shall be heavily insulated and shall preferably be side connected and shall be installed with gate valves and offset gauge cocks. For criogenic services it shall use stainless steel.

4.8.6 Minimum Pressure Rating shall be based on manufacturer's pressure-temperature charts as published. The minimum rating for both reflex and transparent gauges shall be 70.3 kg/cm2 G at 37.7 οC.

4.8.7 Body Material and Cover Material shall be carbon steel. Cast iron is not permitted. Alloy construction, 304 stainless steel, shall be used for all wetted parts where the application requires it.

4.8.8 Frost Extensions shall be provided where operating temperatures are below 0 οC.

4.8.9 Visibility shall cover the operating range of the level instrument(s). In alarm and shutdown service, the visible length shall cover the alarm point but may not cover the shutdown point. Gauge glasses shall be visible from grade, platform or the related instrument. Each gauge glass column shall have a maximum of three sections.

4.8.10 Connections of gauge glasses shall be 3/4 inch NPT screwed top-top and bottom-bottom. Other connection orientations may be used where required.

4.8.11 Gauge Cocks shall meet vessel trim specifications and shall not be considered a combination block valve and safety shut-off cock. They shall have a minimum pressure rating of 210.9

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kg/cm2 G at 37.7 οC. They shall have a 3/4 inch NPT offset union male screwed inlet with a 1/2 inch female union gauge connection. Gauge cocks shall be offset type with ball check on inlet. A back-seating stem and screwed seat shall be furnished. Separate block valves shall be installed between vessel and gauge cock.

4.8.12 Installation shall be in accordance with specification ESP-P-6920.

4.8.13 Servo Gauge or a float and tape level indicators shall be provided for product storage tanks. Interfaces shall be used for communication to SCD.

4.9 Control Valves

4.9.1 Valve Type selection shall take into account such factors as cost, operating (minimum, normal, and maximum) and design conditions, fluid being handled, rangeability required, allowable leakage, noise, and other special requirements. For general services, the following types shall be considered:

a. Cage Guided Globe Valves with balanced or unbalanced type trim. These valves should not be used for dirty services.

b. Globe Valves, single or double ported. Double ported valves shall be top and bottom guided. Single seated valves may be either top and bottom or top guided.

c. Ball Valves of the throttling type.

d. Butterfly Valves with either conventional or shaped discs.

e. Eccentric rotating plug valves of the throttling type.

f. Special Body Types may be considered for special applications such as slurry handling, highly erosive or viscous streams, or for noise control.

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4.9.2 Noise generated by valve shall not exceed 85 dBA at normal flow at 1000 mm away from valve and 1000 mm away from piping.

4.9.3 Characteristics of the inner valve shall be equal-percentage except where system characteristics indicate otherwise. Linear and quick opening characteristics shall be used where required.

a. Equal Percentage Characteristics shall be used on loops that have large variations in valve pressure drops, fast changing pressure control loops, and most flow control loops. In processes where no guide lines are available, equal percentage shall be used.

b. Liner Characteristics shall be used for most level control, slow changing pressure control loops, and loops where the measurement is linear and the variation in the pressure drop across the control valve is small. Linear characteristics shall be used for three-way valves and for two-way valves used in three-way service.

c. Quick Opening characteristics shall be used for on-off service and for direct connected regulators utilizing low lift.

4.9.4 Valve Sizing shall be based on a maximum capacity of 1.3 times the normal flow or 1.1 times the absolute flow, whichever is greater. The manufacturer's "Cv" shall be used to determine valve capacity.

4.9.5 Selected Valve shall pass the maximum flow at 85 percent or lesser valve opening (from a closed position) and shall pass the minimum flow at 15 percent greater of the valve opening.

4.9.6 Body Size shall be one inch minimum. 3/4 inch body size may be used in air and water services for special applications and for pressure regulator services. Reduced ports shall be used as required. The use of odd sizes, 1-1/4, 2-1/2 and 5 inches, shall be avoided. And it shall respect the usual recommendation of relation d/D (valve/pipe).

4.9.7 Minimum Rating for process valves shall be ANSI 300# class for flanged valves and 600 PSIG for screwed valves. (Except that butterfly valves may be ANSI 150# class). In no case shall the valve body rating be less than that permitted by piping specifications.

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4.9.8 Connections shall conform to the following:

a. Flanged Connections for valves one inch and larger in process or steam service, 2 inches and larger in air and water service. Flanges shall conform to ASME B16.34.

b. Screwed Connections may be employed for valves smaller than 2 inches in air and water service where piping specifications permit screwed fittings.

c. Socket Weld Connections may be employed for valves smaller than 2 inches in air and water service where piping specifications do not allow screwed fittings.

4.9.9 Face to Face Dimensions of flanged valves, with integral flanges, shall conform to ASME B16.10. Flangeless bodies such as ball and butterfly valves, and also split body valves, may deviate from these flange dimension requirements.

4.9.10 Body Materials and Rating shall conform to the Piping Specifications. This will call for the following materials:

a. Cast or Forged Carbon Steel shall be used for non-corrosive applications with temperatures above -28 °C and below 400 °C.

b. Alloy shall be used for corrosive service, for temperatures above -28 °C and below 400 °C.

c. Cast Iron may be used only on air service where permitted by piping specification.

d. Cooling Fins or Extension Bonnets shall be provided for temperatures above 230 °C.

e. Butterfly valve bodies shall be heavy duty single flange type minimum. Body and flange rating shall meet piping specification.

4.9.11 Valve Trim shall be stainless steel except for severe service conditions which dictate consideration of other materials.

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4.9.12 Valve trim in the following services shall be hardened with a minimum Brinnel hardness near 400. In cases where severe services require greater hardness, special alloys, or coatings to prevent excessive erosion or corrosion, suitable trim material shall be furnished.

a. Where pressure drop exceed 10.5 kg/cm2.

b. Where erosive fluids or solid-bearing fluids are encountered.

c. All flashing service.

d. All steam service over 3.5 kg/cm2, regardless of pressure drop.

4.9.13 Tight shutoff valve service shall preferably be reinforced Teflon soft seats if Teflon is suitable for the process fluid and process conditions. Where tight shutoff is required it shall be Class V as per ANSI/FCI 70-2 1991.

4.9.14 Guide Bushings shall be of corrosion resistant material. It is preferred that the guide material be a minimum of 125 Brinell harder than the trim.

4.9.15 Packing Glands shall be equipped with flange style gland followers, secured by two bolts. A lubricator with steel isolating valve shall be provided where packing lubrication is required.

4.9.16 Extension Bonnets shall be provided on throttling services above 230° and below -17° C, or in accordance with the manufacturer's recommendation.

4.9.17 Valve Actuators shall be spring and diaphragm or piston type. Electric or electro-hydraulic types may be considered in special maximum differential pressure service to which the valve may be exposed. Actuator shall move valve to open, closed or hold in safe position in case of air or electrical failure.

Interface to electric actuators shall be used for communication to SCD.

4.9.18 Valve Positioners and Booster Amplifiers shall be provided in

accordance with the latest edition of ISA - S75.13.

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Recommended practice is as follows:

a. Controller signal is split ranged between two or more control valves.

b. Controller signal must be amplified to obtain sufficient actuator force.

c. Where better control is required with minimum overshoot from system disturbances and fastest possible recovery. (For example, this may be as a result of stringent process requirements, high control valve stem friction or long transmission lines.)

d. When the system is slow: USE A VALVE POSITIONER (Slow systems are usually those involving thermal or level processes, most mixing processes and a few large gas processes.)

e. When the system is fast: USE A BOOSTER (Fast systems are usually those involving liquid or gas pressure and most flow measurement.)

NOTE: If (a), (b), or (c) above do not apply to a given application, neither positioner or booster is necessary in most cases.

4.9.19 Positioners shall be of the electro-pneumatic type for all services (unless specified otherwise) and shall be furnished with two gages. Positioners shall be easily convertible from direct to reverse acting.

4.9.20 Electric/Pneumatic Transducers, when required, shall be furnished pre-piped and mounted on the valve.

4.9.21 Solenoid Valves, when required, shall meet the area classification and shall be weatherproof. They shall designed for use in the plant control systems and shall operate on 24 VDC and shall be low-power type (1.4 watts maximum. ).

a. Coils for solenoid valves shall be encapsulated and be high temperature resistant for continuous duty at rated voltage and frequency.

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b. Emergency Shutdown related solenoid valves shall be of fast relief type.

c. Valve Bodies for solenoid valves shall follow the piping specifications when used in process lines. Manufacturer's standard brass shall be used for air service.

4.9.22 Tubing shall be 3/8" O.D. 316 stainless steel seamless tube with 0.049 inch wall thickness . Pipe nipples shall be schedule 160 minimum and pipe fittings of 3000 # rated 316 stainless steel. Fittings shall be swagelok compression fittings or equal.

4.9.23 An air set (pressure reducing combination filter/regulator) for air consuming devices shall be supplied with each control valve. Each airset shall be equipped with input and output gauges.

4.9.24 A two inch diameter 0-2 or 0-4 kg/cm2 G pressure gauge mounted on the diaphragm actuated control valve where a positioner is not installed.

4.9.25 Handwheels shall be side mounted declutchible locking type, integral or attached with clamps or bolts.

4.9.26 Guide for Selection of Handwheels or Block and Bypass Manifold

When considering the use of handwheels or block and bypass valves the plant integrity must be protected..

The following guidelines are for determining when to use a handwheel or blocks and bypass valves.

All applications should be evaluated as a part of mechanical flow diagram review.

a. No Handwheel or Block and Bypass

Control valves shall be specified without handwheels or blocks and bypass valve in the following service.

1. Where the control valve can be removed and repaired without upsetting plant operation.

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2. Where the control valve is on non-essential equipment that is operated intermittently and can be isolated without affecting plant operation.

3. Where plant safety would be impaired by either providing a means for blocking flow or opening a valve manually.

b. Block and Bypass Valve Application

Control valves shall be provided with up and down stream block valves and a bypass valve in the following service.

1. Severe operating conditions where the control valve may require servicing between normal plant shutdown, typically in corrosive, erosive or fouling services.

2. For safety considerations as determined by the project.

c. Handwheel Application

Control valves shall be specified with a handwheel in the following services.

1. All control valves not covered by Paragraphs. a. and b. above

NOTE: Handwheels are not good substitutes for block valves and bypass valves. They should be specified for this purpose only after careful consideration. Handwheels can serve as a block valve and for manual control, but for valve maintenance they offer very little.

4.9.27 Procedure for Sizing Block and Bypass Valves Used with Control Valves

In processes requiring block and bypass valves in service with control valves the following criteria are recommended:

Block valves: Use gate valves which are the same size as the control valves, but not less than one size smaller than line size.

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Bypass valve: Cv of bypass valve shall be, at least the calculated Cv of the control valve, but not more than twice the selected Cv of the control valve.

Globe valves shall be used up to 4” (Cv=200). If the bypass valve Cv requirement is >200, a gate valve with the required Cv shall be used. See table below. When gate valves are used as bypass valves, their minimum size shall be two sizes under line size.

Sizing Notes

1. In applications where high pressure drop may occur, and flashing is possible, the sizes of block and bypass shall be determined by process calculations. Bypass valves may need to be oversized for process reasons, such as startup (faster filling or emptying a system) or gravity draining.

2. When sizing blocks and bypass for control valves with small sizing ∆P, look at the manifold pressure drop. The Process Engineer does not consider manifold pressure drop when he gives sizing ∆P for a control valve.

VALVE CAPACITIES (Cv) TABLE

Size Globe(2) Gate(1) Ball (2) Plug-

Cock(3) Butterfly(4) Vee-Ball(4)

1” 10 70 45 25 23 1 1/2” 26 170 125 55 26 86

2” 48 310 165 144 55 127 3” 110 720 350 254 136 240 4” 200 1350 775 433 271 552 6” 480 3100 1000 900 768 1110 8” 865 5700 2000 1400 1340 2070 10” 1370 9000 3150 2100 2170 3160 12” 2000 13500 5200 3100 3180 4620

CAUTION: Actual project selected vendor should be consulted for exact Cv data.

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NOTES: 1. Data from Crane Technical Paper No. 410, dated 1976 2. Data from Jamesbury Bulletin 284, dated 1977

3. Data from Tufline Catalog CV-1, dated 1977 4. Average of data from Fisher Controls Catalog 10, dated 1976

TYPICAL EXAMPLES

Control Valve Size

Calculated

Cv

Selected

Cv

2 x Selected

Cv

Bypass Valve

Cv Requirement

Type &

Size Valve

1” 3 4** 8 3-8** 1” Globe 2” 30 44 88 30-88 2” Globe 3” 55 104 208 55-208 3” Globe 4” 160 180 360 160-360 4” Globe 4” 202 224 448 202-448 2” Gate 6” 261 395 790 261-790 3” Gate

** Reduced trim, pick bypass w/reduced trim if available or use next largest size.

TYPICAL BLOCK AND BYPASS VALVE SIZING CHART

Control

Valve

Size

Line Size

1 1 1/2 2 3 4 6 8 10 12

Blo

ck

Byp

ass

Blo

ck

Byp

ass

Blo

ck

Byp

ass

Blo

ck

Byp

ass

Blo

ck

Byp

ass

Blo

ck

Byp

ass

Blo

ck

Byp

ass

Blo

ck

Byp

ass

Blo

ck

Byp

ass

1 1 1 1 1- 1 1/2 1 2 1 - - - - - - - - - -

1 1/2 - - 11/2 11/2 11/2 11/2 2 11/2 3 11/2 - - - - - - - - 2 - - - - 2 2 2 2 3 2 4 2 - - - - - - 3 - - - - - - 3 3 3 3 4 3 6 3 - - - - 4 - - - - - - 4 4 4 4 6 4 8 4 - - 6 - - - - - - 6 3* 6 4* 8 4* 10 8 8 - - - - - - 8 4* 8 4* 10 8*

10 - - - - - - 10 6* 10 8* 12 - - - - - - 12 8*

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*Gate type bypass valve

4.9.28 Automatic deluge valve shall be used to on-off in control water flow. The valve can be installed in any position service without physical damage. The valve shall supplied with accessories solenoid valve, limit switches, etc.

4.9.29 Two-stage electric control valves shell be used for those applications where requiring precise shut-off in loading trucks.

4.9.30 Internal safety shut-off and operating valve shall be use for safe tanks in case of fire. The accessories such as fusible plugs and strainer assembly shall be supply with the valve. The valve size and flange rating shall be in accordance with piping specifications.

4.9.31 Pressure regulations shall be used for pressure control applications in services of water and shall can handle pressures up to 42.16 kg/cm2 and temperatures up to 343.3 °C.

4.10 Pressure Safety Devices

4.10.1 All Pressure Relieving Devices Shall be Sized in strict accordance with applicable local, state, and national code requirements. Formulae shall be in accordance with API RP 520.

4.10.2 Percent Accumulation used in calculating sizes of relieving devices shall be as follows:

3% Steam service where ASME Power Boiler Code applies.

10% Gas or vapor service, and liquids, except as noted below.

16% Vessels protected by multiple relief valves.

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21% Fire exposure or unfired pressure vessels.

25% Liquids - for thermal relief of pipelines and pump discharges.

4.10.3 Nomenclature used shall be in accordance with API RP 520.

4.10.4 Safety and Relief Valves in general application, shall be spring operated. For other services the type of safety and relief valves will be determined in accordance with the service application. Balanced bellows valves shall be considered for relief into closed flare and blowdown systems. Pilot operated pressure relief valves may be specified for services where the set pressure less than 110% of the operating pressure.

4.10.5 Full Nozzle Type Valves shall be specified for sizes one inch and larger.

4.10.6 Base or Modified Nozzle Type Valves shall be specified for thermal relief service. Sizes shall be 3/4 inch x 1 inch for all liquids.

4.10.7 Rupture Discs may be used in lieu of or in combination with safety and relief valves, where applicable or required. When used in combination, an excess flow check valve and pressure gauge shall be installed in the vapor space between the rupture disc and relief valve.

4.10.8 Pressure and Vacuum Relief Valves for storage tanks shall be of the weight loaded or pilot operated type, and sized in accordance with API Standard STD 2000.

4.10.9 Safety Valves for Steam Turbine Casings shall be as follows:

a. Non-Condensing Turbine Casings shall be equipped with relief valves of the sentinel type for warning purposes only. If the turbine is the type that starts automatically, full relief is required. When full relief is required, NEMA Standard SM 23 shall be used for sizing.

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b. Condensing Steam Turbine Casings shall normally be equipped with relief valves of the atmospheric type giving full relief. NEMA Standard SM 23 shall be used for sizing.

4.10.10 Materials of Construction shall be as follows:

a. Steel Bodies with Stainless Steel trim shall be specified.

b. Steel Bodies shall be specified for thermal relief in cooling water service and air service, provided piping specifications permit.

c. Aluminum Bodies shall be specified for API storage tank pressure and vacuum relief valves, providing piping and vessel specifications permit.

d. Alloy Bodies or Special Materials shall be specified where required because of process, atmospheric, or operating conditions.

e. Springs shall be carbon steel for normal process operating temperatures of -60° C through 230° C, tungsten alloy steel above 230° C and ANSI 316 stainless steel from -60° C to -240° C.

4.10.11 Bonnet Construction shall be as follows:

a. Plain Closed Bonnets shall be specified, with a tapped and plugged vent for easy conversion to a balanced type valve.

b. Exposed Spring Bonnets shall be specified for steam service above 230° C, as required by ASME Power Boiler Code, Paragraph PG-68.6.

4.10.12 Connection Sizes and Ratings shall be as follows:

a. Flanged Connections shall be furnished on all safety and relief valves, one inch size and larger. Minimum rating shall be 150# ANSI. Valve flanges shall match rating and facing of mating flange on vessels or piping. Body flanges shall be per ASME B16.34.

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b. Screwed Connections shall be furnished on valves 3/4 inch and smaller unless process or operating conditions do not allow. Threaded connections on valves shall be per API SPEC 5B taper pipe threaded ends.

4.10.13 Accessories

a. Plain Lifting levers shall be furnished for exposed spring bonnets on safety and relief valves in ASME Power Boiler Code Service and on air valves with closed bonnets on plant air receiver service.

4.10.14 Code Stamps shall be furnished with safety valves where applicable.

4.10.15 Closed Relief Valve Discharge Systems shall be designed in accordance with API RP 520.

4.10.16 Inspection and Testing of safety and relief valves shall be performed in the field and shall be witnessed by the Owner's representative. Set pressure tolerances shall be at least as good as required by ASME Unfired Pressure Vessel Code, paragraph UG-133 Section VIII, DIV. 1.

a. Seat Tightness - Metal-to-Metal seats shall be specified as "Commercial Tightness", which permits a stipulated maximum leakage at a specified percent of set pressure. "Bubble Tightness", which permits no leakage at specified percent of set pressure, shall be specified when required by process conditions or customer requests.

b. Testing for Tightness shall be in accordance with API RP 527.

4.10.17 Full Area Block Valves - When Block valves are provided, they shall be on both inlet and outlet of the relieving device and shall be of "Locked Open" or "Car Seal Open" type. A bypass valve shall also be provided for manual relief if needed. Some relief valve installations shall also have testing taps at the inlet and outlet, as shown on the P&ID.

4.11 Drainers

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4.11.1 Ball Float Traps (Continuous Drainers) shall be used for modulating service such as draining condensate from temperature controlled reboilers, for trapping liquids in gas or air streams, and for venting air or gas from liquid streams. For large volumes of condensate removal, fabricated surge pots with displacement level controllers and pneumatic control valves may be used. Consider use of surge pots and level controllers on major exchangers.

4.11.2 Strainers shall be installed in the piping upstream of all drainers. The use of integral strainers shall be considered where they are available as a manufacturer's standard, and can be blown down or removed without disassembling the drainers. Strainer body and gasket materials shall be in accordance with piping material specifications.

4.11.3 Trim Material shall be stainless steel except that special parts such as bellows or bimetallic elements shall be manufacturer's standard.

4.12 Switches

4.12.1 Switches for Alarms and Interlock Systems shall be used for on-off applications only. When outdoor installations are required, they shall meet the area classification and be weatherproof. Switches in equipment shutdown service shall be directly connected to the process. Wiring for switches shall be two conductor and shall not use the common hot wire technique.

a. Switch Contacts shall be specified double-pole, double-throw, wherever possible for versatility. Contacts shall be specified 1A, 24 VDC for instrument services and 5A, 120/240 V, 60 cycle when used to operate motors and other heavy duty electrical devices.

b. Switch Action for alarms and shutdown shall be closed circuit for normal operation; open circuit for alarm/shutdown condition. Switch action for hardwired interlock and shutdown may be either normally open or closed for normal operation, depending on type and

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reliability of power source and on nature of interlock wiring (so as to avoid need of interposing relays).

4.12.2 Level Switches shall be the external float cage type with one inch NPT screwed or socket-weld connections. Body material and rating shall conform to piping specifications. Internal trim shall be stainless steel unless other materials are required for service. Installation shall be in accordance with Job Installation Drawings. Level switches in alarm service may be receiver pressure switches when there is a level transmitter as part of the system. Level switches in equipment shutdown service shall be direct operated type.

4.12.3 Pressure Switches for direct connected process and utility service shall be diaphragm or bourdon tube type with materials suitable for the service. They shall meet the hazardous electrical classification and shall have micro switches. Connections shall be 3/4 inch NPT.

4.12.4 Temperature Switches, locally mounted in hazardous classification Division 1 locations, shall be filled system bulb type or expansion type. They shall meet the electrical classification and shall have micro switches.

4.12.5 Flow Switches for direct operation by process fluids may be of the sight flow, rotameter, or paddle type for low accuracy requirements. Orifice plate, thermal dispersion and differential pressure type transmitter shall be used for high accuracy requirements.

4.13 Analyzers

4.13.1 Analyzers and Specialty Instruments are specified to directly or indirectly measure the concentration of one or more components in a process stream or to measure some property that is of interest in meeting specifications of the stream.

4.13.2 Analyzer Selection shall not be limited by this standard. Since new types of analyzers and new applications for existing analyzers are frequently available, this standard shall be used only as a guide

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4.13.3 Gas Chromatographs are specified when it is necessary to determine several components simultaneously or a single component in a mixture.

a. Applications for gas chromatography include gas or vapor streams and liquid streams which can be vaporized at the operating temperature of the analyzer. If the stream is dirty or contains non- volatile components, these undesired components must be removed in the sampling system. The instrument vendor shall supply the application data needed for the analysis.

b. The components of a chromatograph include the sample conditioning system, analyzer's cabinet, control unit, and readout. The analyzer cabinet shall be as near to the point being sampled as is practical, and may be installed in the field. The control unit may be mounted either in the field or in a control room. The readout device shall be in the control room.

4.13.4 Infrared Analyzers are specified for the analysis of a single component in a gas vapor stream. Special precautions to avoid wet samples are necessary if salt windows and optics are required.

4.13.5 Thermal Conductivity Analyzers are recommended for the determination of hydrogen purity. They may also be applied to other two-component determinations.

4.13.6 Paramagnetic Analyzers are specified only for the determination of oxygen in gas streams. Two types of sensors are available which include the "dumbbell" and the thermal sensing unit. The thermal unit is preferred since it is not as fragile as the "Dumbbell" sensor.

4.13.7 Electrochemical Analyzers are specified to measure the properties of water solutions. They are also widely used for the determination of pollution.

4.13.8 Colorimeters, Dispersive Ultraviolet, and Turbidity Instruments are applied to liquids and sometimes gases. Colored materials or materials absorbing in the ultraviolet region may be determined.

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4.13.9 Liquid Density Instruments are specified when the concentration of a solution is to be determined or when density is a variable of a process stream. A number of types are available including displacement instruments, "U" tube gravimetric instruments and radiation absorption instruments. The "U" tube type is preferred since it is less sensitive to flow. It does, however, have temperature and pressure limitations which may dictate a choice of another type. Temperature compensation is required if the temperature of the stream is not reasonably constant.

4.13.10 Gas Density Analyzers are specified to determine purity of hydrogen streams, carbon dioxide in stack gas and other purposes. The mechanical type with rotation impellers is most commonly used. A second type where the unknown gas impinges on a stream of known gas with the resulting flow being thermally detected has been developed. Temperature compensation is not normally required for either instrument.

4.13.11 Atmosphere Monitors are specified to warn of toxic or other hazardous conditions.

4.13.12 Sampling Conditioning Systems are as important as the choice of the analyzer. The sample system is furnished by the same Seller who supplies the analyzer.

a. Gas and Vapor Systems

1. The system volume shall be kept to a minimum. 1/4 inch stainless steel tubing shall be used. Other materials may be used if sample compositions and conditions permit.

2. For gas samples, the pressure should be reduced at the sampling point to increase the velocity through the sample system and reduce time lag. This pressure reducing valve is outside of the sampling system supplied by the instrument Seller.

3. Sample bypasses around the analyzers shall be supplied. This insures that the sample lines are purged and it reduces the time lag of sampling. The sample bypass is either vented to atmosphere or back to a lower pressure part of the process.

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4. The sample must be clean and free of particles. Install a "Y" strainer immediately ahead of the primary pressure reducer. Additional filters, strainers and drainers which may be required should be specified as part of the system. Water washing of the stream may be required with dirty samples such as stack gas. The water should be recycled with only a small makeup and drain stream to minimize composition changes.

5. Desiccants should be avoided when drying a sample stream. Chilling and trapping the moisture is preferred. Desiccants may become spent and not function or they may absorb constituents other than water.

6. Steam tracing or insulation of the sample line is required if condensation of the sample can occur at ambient conditions. A heated cabinet shall be provided by the manufacturer for the sample conditioning system if there is danger of condensation.

b. Liquid Systems

1. When a liquid stream must be taken to the analyzer, the sampling is similar to a gas or vapor system. Filtering, pressure reduction, cooling or heating may be required. The extent of sample conditioning required shall be governed by the process stream.

2. Liquid bypasses around the analyzer shall be provided to reduce sampling lag. They shall be drained to a sewer or a lower pressure part of the process.

3. Electrolytic conductivity, pH, or similar probes shall be installed in a bypass line so that it is not necessary to interrupt the process to service the electrodes.

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4.13.13 Electrical Wiring of the instruments shall conform to the National Electrical Code. With large instruments such as analyzers that cannot be mounted in an explosion-proof box, air purging may be required. ISA Standard S12.11 shall be followed. If possible, mount the analyzer in a non-hazardous area.

a. The control circuits of the analyzer shall be powered from the control panel. Each analyzer shall have an over-current protective device, (magnetic type circuit switch or a fuse). Local disconnect switches shall also be provided so that the instruments can be safely serviced. Cabinet heaters, circulating pump motors and other devices which draw relatively high currents may be powered locally.

b. Signal wiring shall be run to the control room in separate conduit or cable. It shall be routed to the receiver instrument by the shortest most direct route feasible. Supply of special cables by the instrument Seller shall be considered.

4.13.14 Process Control Loops which include an analyzer shall be cascaded. In cases where the analyzer is continuous and not delayed, direct output control may be provided.

a. Holding circuits shall be provided when the analyzer output is intermittent. The output of this device may be used for trend recording in addition to providing signal for the control loop.

b. Converters to provide a current or pneumatic output shall be provided if required. These devices shall be mounted at the control panel. In cases such as with boiling point analyzers, a pneumatic output may be obtained directly.

c. Repeater amplifiers with grounded input and floating output are often required when the analyzer is used with electronic controllers. In cases where the grounded output of the analyzer causes no problems the receiver repeater is normally floating. A repeater is normally necessary when the receiver input is also grounded.

4.13.15 Walk-In Type Houses shall be provided for most analyzers.

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4.13.16 Calibrating Gases shall be furnished for analyzer calibration where practical.

4.14 Receiver Instruments

4.14.1 Local Flow Indicators shall be the filled bellows type. Body material shall be carbon steel with stainless steel bellows in process service. Minimum working pressure shall be 50 kg/cm2 G. Cases shall be weatherproof.

a. Range shall be 2500 mm water column dry differential. Where a larger range is required, a differential of up to 6000 mm water column may be used in lieu of increasing the meter run size.

4.14.2 Pressure Controllers. non-indicating, pilot-operated type may be used for applications where transmission to remote receivers is not required. The pressure sensitive element and controller shall be mounted in a weatherproof case or housing suitable for valve. Direct connected pressure gauges shall be piped in parallel for local indication. An adjustable proportional band of at least 2-200% and a convenient control point setting shall be provided. Output of the final control element shall be 0.2-1 or 0.4-2 kg/cm2 G.

4.14.3 Panel Mounted Electronic Controllers shall be narrow (nominal 75 mm x 150 mm), vertical or horizontal scale, indicating deviation type, mounted side by side or in multi-high density enclosures. The controllers shall have a center scale set point with a clearly identified off-normal display.

4.14.4 Automatic - Manual Transfer Control shall be furnished with panel mounted controller and shall be provided with bumpless transfer from automatic to manual control and vice versa.

4.14.5 The Annunciator Alarm System for the main control room shall produce both visual and audible signals. Visual signals shall be the backlighted type. Acknowledge and test switches shall be provided.

a. Sequence of Alarm shall normally be FIRST OUT per ISA S18.1 F3A-14.

1. NORMAL: Light is out and horn is silent.

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2. PROCESS ABNORMAL: First alarm - intermittent flashing light and horn is audible. Sub alarm - fast flashing light and horn is audible.

3. ACKNOWLEDGE BUTTON PRESSED: First alarm - slow flashing light and horn is silent. Sub alarm - light is steady and horn is silent.

4. PROCESS RETURNS TO NORMAL: Light goes out.

b. Annunciators, local panel-mounted for packaged and rotating mechanical equipment, shall use a first out identification sequence.

c. Annunciator Design shall be in accordance with ISA S18.1.

d. One Common Alarm Point shall be provided in the main control room annunciator to indicate an alarm condition on any locally mounted annunciator.

e. Each Annunciator shall have capacity for 15% to 25% extra points and shall have 10% to 15% spare relays or cards.

4.14.6 Control Panels shall be free-standing type with open frame back, constructed in convenient sections to facilitate shipment and installation. They shall be non-graphic, and in the case of main control panels, shall be arranged for high density, multi-instrument housings or channels. When a Process display is desired, consideration should be given to a semigraphic section, annunciation-process display, projector display, or other.

4.14.7 Panel Construction shall be from 10 guage hot rolled steel plate with angle iron or Unistrut-type frame and mounting racks. The panel shall be fabricated, sand blasted, and all irregularities removed, after which a suitable primer surface shall be applied. The primer shall be followed by two coats of light green paint. For economics, or other reasons, consideration may be given to other construction methods, such as relay rack construction, or console type design.

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4.14.8 Recorders circular chart type shall be used for local services only.

4.14.9 Local control unit shall be of type electronic preset blending system to be used in ship loading terminals. Shall be microprocessor 32 bit high speed architecture with memory capacity for faster response. Shall be provides precise batch delivery for custody transfer of petroleum industrial and chemical products. Shall be supply with display, keypad, operator prompts and program menus. LCU shall be explosion proof housing.

4.14.10 Flow computer shall be used for makes complex calculations based in AGA 3 equations with pressure, temperature and gravity compensation displays totalization of flow, diagnostics and alarm functions. The data of totalization shall indicated in standard condition of PGPB, too.

4.14.11 Ground connection system shall be used for safety on loading trucks.

a. Wiring On Main Control Panel In A Non-Hazardous Area shall be in plastic ducts routed to the instrument housings. Power wiring to instruments may be installed with plugs and cord sets and a continuous convenience outlet duct. All signal or alarm wiring shall terminate on clearly identified terminal blocks. Power wiring to be minimum 3.5 mm2 (12AWG) THHN while signal and alarm wiring to be minimum 1.5 mm2 (16AWG) THHN.

b. Intrinsically Safe Wiring shall be run in separate conduit, wireways, etc., from other wiring.

4.14.12 Instrument Nameplates for miniature instruments shall be furnished on the instrument bezels by the major instrument Seller showing the Tag Number and Service. Other nameplates may be furnished on the panel front located beneath the instrument. All instruments shall have a rear mounted nameplate showing the Tag Number.

4.14.13 Arrangement of the Major Control and Recording Instruments shall be such that the centerline of the lowest instrument is not below 800 mm (2 feet 6 inches) and the centerline of the

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highest instrument is not above 1400 mm (5 feet 6 inches) from grade. Horizontal and vertical spacing of instruments shall be as such to facilitate maintenance and panel construction.

4.14.14 Electrical Classification of the main control panel and panel instruments in the control house shall be nonhazardous. Local control panels shall meet the electrical classification for the area.

4.14.15 Wiring shall comply with the requirements of the National Electrical Code for the area classification where the panel is installed.

a. Wiring On Main Control Panel In A Non-Hazardous Area shall be in plastic ducts routed to the instrument housings. Power wiring to instruments may be installed with plugs and cord sets and a continuous convenience outlet duct. All signal or alarm wiring shall terminate on clearly identified terminal blocks. Power wiring to be minimum 3.5 mm2 (12AWG) THHN while signal and alarm wiring to be minimum 1.5 mm2 (16AWG) THHN.

b. Intrinsically Safe Wiring shall be run in separate conduit, wireways, etc., from other wiring.

5.0 INSTALLATION

5.1 Installation shall be in accordance with Specification ESP-P-6920.

5.2 Level elevations shown on P&IDs for each vessel indicate the alarm or trip value and not the elevation of nozzles on the vessel. Level nozzles on the vessel shall be located such that the level instrument will be able to provide alarm or trip at the elevation indicated on the P&ID. The level transmitters shall cover 110% above high-high level point, 120% above high level point, 20% below low level point, and 10% below low-low level point.

5.3 Tropicalization shall be provided for field mounted instruments. The instrument manufacturer's standard tropicalization shall be indicated on data sheets.

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5.4 All instruments and instrument process lines subject to freezing shall be heat traced, filled with seal fluid, purged or otherwise protected. These instruments and process lines shall be identified on P&ID's.

5.5 Connection sizes on vessel/piping as follows

Type of Measurement Connection Sizes on Vessel/Piping

Flanged RTJ

To be used only when required by piping or vessel specification

Analysis 2" min. 2" min.

Flow -- --

Level - Screwed d/p cell -- --

Flanged d/p cell 3" min 3" min

Displacer 2" 2"

Magnetic Gauge/Transmitter

2” 2”

Gauge glass 2" 2"

Bridle system 3" 3"

Pressure 2" 2"

Thermowells 2" 2"

5.6 Instrument Support Brackets shall not be welded to process piping (except as required by piping stress analysis on high temperature steam lines).

5.7 For mass flow sensors, it shall make pipe preparations.

ESP-P-6000

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Transcript of ESP-P-6000