QUALIFICATION OF WELDING PROCEDURES AND WELDERS

1.1    Welding Procedures
Welding procedures shall be in writing and shall be qualified in accordance with ASME Boiler and Pressure Vessel Code, Section IX. All welding procedures shall be identified by a unique number and shall be referenced on all applicable fabrication drawings.
These procedures shall include the following: Welding Procedure Specifications (WPS), Procedure Qualification Test Records (PQR), ranges of variables qualified, a weld map or description identifying which welding procedure will be used for each weld, method and extent of inspection. For piping, representative weld maps illustrating the applicable weld procedures are required. 

1.2    Qualification of Welding Procedures
The P-number (as defined in ASME Code, Section IX) shall be considered an essential variable for all welding processes. Materials having no P-numbers shall be qualified individually. Note that any changes in essential variables require.
Welding position shall be considered an essential variable for groove welds in all automatic welding processes. Note that welding position is an essential variable for welder qualification.
All welding consumables not listed in the ASME Code, Section II, Part C shall be individually qualified.
For submerged arc welding, brand name and grade of flux shall be considered an essential variable, together with changes in speed or heat input beyond the range qualified. The procedure qualification test record shall indicate the name of the manufacturer sand the trade name of the wire and flux used to qualify the procedure.
Postweld heat treatment (time and temperature) shall be considered an essential variable for P-3, P-4, P-5, and P-6 materials.
Welding procedure qualification impact testing of welds and heat-affected zones (HAZ) for ferritic materials is required at the minimum design temperature.
When impact testing is required, the Charpy V-notch impact values for parent material, weld metal and heat-affected zones shall not be less than those specified in ASME B31.3 for piping. The impact test shall be performed on the same type (ASTM or other similar specification) and grade of material as will be used in fabrication.
Procedure qualifications for weld overlay deposits shall include complete chemical analysis of the overlay, procedure qualification test record, and sample of the overlay. The procedure qualification tests shall include:
a.  Dye penetrant examination of the completed weld.
b. Side bend tests and longitudinal face bend tests for weld metal soundness. Cracks at specimen edges shall not be considered part of the examination.
The welding procedure qualification tests shall include hardness tests for the following quenched and tempered carbon steel, high-strength low-alloy (HSLA) steel, carbon-molybdenum (C-Mo), manganese-molybdenum (Mn-Mo), chromium-molybdenum (Cr-Mo) steels; martensitic stainless steels and other air-hardenable materials.
Procedure qualification tests for welding carbon steel shall also include a hardness survey if any of the following conditions exist:
a)   Submerged arc welding is performed with F8XX or higher flux designation
b) Shielded metal arc welding is performed with covered electrodes of E80XX or higher  classification
c) Job specifications or data sheets require a maximum specified hardness in the weld and /or heat-affected zone
d) Process conditions (wet hydrogen sulfide, amine, hydrogen fluride, and caustic) require production hardness testing
The  hardness  testing for welding procedure qualification shall be performed on the base metal, weld, and heat-affected zone with an instrument having an indentor nor larger than 1/16 inch   diameter  (such  as  Vickers 10  kg load,  Rockwell  B  and C). The hardness shall be reported as Brinell (BHN), Rockwell B or C, or Vickers (HV) equivalent numbers. Hardness  surveys shall be performed along two lines  parallel  to the outer  and inner surfaces of the weld and located approximately 0.08 inch below them (Figure 1). The type of hardness test instrument shall be reported and the test result shall meet the hardness requirement of 225 BHN (238 HV10, Rc 20) maximum.
For gas tungsten arc and gas metal arc welding, the qualification record shall include the composition and flowrate of the shielding gas and inert gas backing, when used.

PETROLEUM FIREWATER SYSTEMS DESIGN

Fire-water systems shall be installed on petroleum Plant to cover the fire-water needs of each plant. This document describes the minimum facilities and fire-water capacities required to meet the statuary requirements.

The permanent systems used for protection of equipment usually consist of a combination of deluge, water sprays and fixed monitors.

·         A water deluge system is one in which all the water is applied at the top of the vessel and allowed to run down the sides.

·         A water spray system uses many nozzles arranged in a grid pattern to distribute the water evenly over the vessel.

·         Fixed monitors are permanently connected to the fire-water grid system and directed at the protected unit.

·         Gas Turbines/Compressors/Expander

Gas turbines/compressors/expander packages are not water protected as the units are enclosed and protected by CO₂ total flooding systems.

·         Vessels

All vessels containing hydrocarbon liquids are water protected including their supporting skirts.

·         Drain System

Closed Drain Drum is deluged as well as the Closed Drain Pump.

·         Compressor Discharge Coolers

Compressor discharge coolers are not water protected as those coolers are air cooler type and contain little or no liquid.

·         Overhead and Bottoms Air Coolers

Liquid filled coolers are water protected; those with condensing liquids are not water protected.

·         Emergency Generator

The driver of the Emergency Diesel Generator and its feed vessel will be deluged only if fire is detected in its area. A dedicated deluge valve shall be provided for the skids.

·         Pressurized LPG Spheres

Each LPG storage sphere shall be protected either by a water deluge system or water spray system, to protect against pool-fire exposure, supplemented by fixed monitors.

Fire-water Flow Rates

The minimum flow rates used in determining the total fire-water flow rate are shown in Table

Flow is initiated only in the zone(s) where the fire is detected. In the remaining zones, flow can be initiated manually. Fixed sprays or deluge cover equipment and critical valves. Monitors and hydrants operation is manual.

SPRAY NOZZLE SELECTION

The spray nozzle shall be effective at the minimum discharge pressure given in NFPA 20 of 40 psig. In general spray nozzles are fully effectively from 50 psig upwards (3.5 barg).

For example: D3 Protect spray Nozzle No. 21, K = 25.9 @ 3.5 barg

Q =    Flow rate, 48.5 litter/minute

P  =    Pressure, bar

K =    Nozzle constant (by vendor)

Litters / minute

Contractor shall fully design the actual fire-water network in detail engineering and all assumed parameters in this document shall be recalculated to give the optimum fire-water system.

CONNECTIONS PIPE TO EQUIPMENT

Piping shall be erected and supported in a manner that will not put undue strain on equipment such as compressors, engines, pumps, vessels and heat exchangers. Cold pull shall be to Company’s approval.

The following procedure shall be observed:
·            Initially, piping shall be attached to the equipment using finger tightened bolts
·            Flat face flanges and full face gaskets shall be used on piping connecting to equipment with flat face flanges only.
·            Flanges shall be checked to ensure that no strain is placed on the equipment. If the pipe is not in correct alignment it shall be removed and corrected. The correction in alignment shall not be made while the pipe is connected to the equipment.  Heating of piping to correct misalignment shall not be permitted.

·            Finally tighten bolts to correct torque.

·            All brazed aluminum heat exchanger misalignment tolerances, bolt torque values and flange tightening procedures shall be strictly observed. Hammer wrenches shall not be used. Company shall witness all brazed aluminum heat exchanger flange bolt-ups.

Cold pulls shall be approved by Company.

The following procedure shall be applied for the alignment of flanges to rotating equipment:
·            Align pipe work to equipment flanges to within the more stringent of either the manufacturer’s tolerances or ASME B31.3. Adjust pipe support where necessary.

·            Flange faces shall be parallel within 1/16” measured across any diameter.

·            Bolt up piping to equipment flanges and torque the bolts to the specified tension.

·            Check the coupling alignment during the bolting and tensioning of the pipe flanges to the equipment flanges. The bolting up and tensioning of the flanges shall not affect the coupling alignment between the driver and driven equipment.

·            Check setting of pipe support.

·             Finally tighten bolts to correct torque.
Flange Connections

Flange connections shall be made up as follows:

·            Clean protective grease from flange gasket faces and position for bolt up.  Flange faces shall be parallel and aligned axially in the horizontal and vertical plane to the tolerances. Position gasket and install bolts and nuts to hand tight.

·            All bolts for flanged connections require extreme attention in assembly to ensure uniform loading on the gasket surfaces.  Non uniform bolt loading, dirt at the mating surfaces or scratched flange surfaces shall be subject to release and flange joint re-assembly or flange face redressing.

·            Regardless of the scheme selected for flange joint assembly, i.e. gauge between flanges, torque wrench or bolt elongation, it is important to tighten uniformly and not prematurely set the gasket.  Hand tighten all nuts first, and then gradually tighten opposite nuts on the flange.  Do not bring a single nut to full tightness before the others have been carefully stepped up toward this final position.

·            Flange bolt and stud threads shall protrude a minimum of ¼ inch or two full thread pitches, whichever is the greater, past the nut. Extremely long bolt projection will not be accepted unless required for hydraulic tensioning.  Uniformity of bolt projection through the nuts of stud bolts shall be observed.

·            New gaskets shall be used whenever a set of flanges is broken apart and then re-connected.
FRP Flange Connections

All flanged joints shall be uniformly tightened and shall be torque no more than the pipe manufacturer’s recommended limit.

FRP flanged joints shall be fully tightened, with the pipe support to FRP pipe clamps loose.

The FRP pipe clamps shall be tightened only once final flange bolting shall have been completed.

Washers shall be used at all bolted connections where all FRP flat faced flanges mate together or with wafer type valves. Flat faced flanges shall not be used with raised faced flanges.

The specification break between carbon steel and FRP piping shall utilize flat faced carbon steel flanges.

PRINCIPLE INSTRUMENTATION OF PETROLEUM PLANT

Instrumentation System Overview

Petroleum plant shall have instruments for measurement and control that are of field proven design and high quality.

The various instruments involved mainly cover the following:

• Flow Instruments: Integrated orifice plate, senior orifice fitting, restriction orifice,        multivariate flow transmitter, coriolis meter, V-cone meter
• Level Instruments: Level gauge glass, displacer (external) type, float type for level transmitter and level switch 
•  Pressure Instruments: Electronic pressure transmitter, pneumatic pressure transmitter, pressure switch, pressure gauge, pressure indicating controller, pressure differential indicator
• Temperature Instruments: Electronic temperature transmitter, temperature gauge, temperature switch 
•  Fire and Gas Detectors: IR3 Flame detectors, UV/IR Gas detectors, Fusible plug 
•  Valves: Control valve, solenoid valve, on/off valve/actuator, pressure safety valve, pressure regulator valve 
•  Miscellaneous: Instrument cables/Trays & accessories, instrument mounting/hook-up accessories, power supply distribution facility, multi-cable transit block, instrument calibration/maintenance tool, etc.

Instrumentation in Package Unit

Instruments for package units shall fully follow the guidelines, philosophy and standards that defined in this specification for selection, design, and installation.

The instrument package vendor shall fully equip all related instruments and control, and services necessary to ensure the delivery of a fully operational package. Package vendor shall be responsible for the project liaison and detailed engineering of all his equipment, instrumentation, and materials manufacturers, fabrication, assembly, calibration, and their quality of workmanship in complying with this specification.

Hazardous Areas

All instruments located in hazardous areas shall be certified & approved for use in accordance with the applicable area classification.  All outdoor instruments and related equipment shall as a minimum be certified to NEMA 7 for installation in API 500 Class I, Division 1 hazardous area, or Division 2 as required by classification drawings.

 The vendor must provide test certificates & approval certificates from statutory authorities like UL or FM for all instruments and related equipment as applicable for weather protection or for their use in hazardous areas.

Environmental Protection

All instruments, enclosures and related equipment installed in open areas of the facilities must be certified to NEMA 4X for weatherproof requirement. All field instruments and associated equipment shall be manufactured of materials suitable for service under the specified environmental conditions over the design period. All field instruments, structural supports and frame works manufactured of carbon steel.

THE PIPING VALVE TYPE

Primary isolation valves shall be shown on the P&ID and identified in accordance with valve identification number. Isolation valves shall be provided for all instrument connections, isolation of equipment that can be serviced when bypassed, multiple (spare) pump installations, etc.

The valve type shall be in accordance with each specific piping material class specification no. Valves description will as given in the valves specification no.  All valves shall be furnished with manual operators unless specified otherwise.

Gear Operators, as furnished by the valve manufacturer, shall be provided for large valves which satisfy both of the following conditions:

Class 150 rating	10” size and larger
Class 300 rating	8” size and larger
Class 600 & 900 rating	6” size and larger
Class 1500 & 2500 rating	4” size and larger

Gear operators shall be sized such that its output torque is at least 1.5 times the maximum required operating torque of the valve proper and shall be suitable for operation in a tropical environment.  The gear ratio shall be maximum 1:60 for valves NPS 8 and smaller or maximum 1:120 for valve NPS 10 and larger.  Gear operators shall be self locking and be provided with a position indicator.

All valves shall be capable of being locked in the open or closed position with a positive position locking device other than chain.

Block valves shall in general be ball valves of fire safe design in accordance with API 607/API 6FA or equivalent and a copy of the certification shall be provided. Butterfly valves may be used in cooling water services. Globe valves will be used when throttling is required.

Valves shall be provided with pressure equalizing bypasses when high differential pressure exists across the closed valve. Valves for which bypasses are to be furnished and the size and type of bypass valve will be shown on the applicable flow diagram.

All 2” size and larger valves shall have flanged ends. 1½” and smaller size valves shall have flanged or socket weld ends.

Check valves will be provided for all lines tying into common headers, or to prevent back flow.

Flanged end valves which are described as outside screw and yoke (OS&Y) in the valve classification tables shall be provided with stem protectors.

Globe, ball, check, and slab-type gate valves shall be field repairable. Balls, seals and seats shall be replaceable without welding or cutting.

Valve dimensions shall be identical to the dimensions specified in ASME B16.10, Face-to Face and End-to-End Dimensions of Ferrous Valves.  Face-to-face dimensions shall be long patterns.

All valves except check valves shall be capable of sealing with design pressure applied from either end of the valve.

Unless otherwise specified, valves shall be suitable for oil, water, and gas service throughout the temperature range of the pressure class.

Double seated valves capable of sealing simultaneously against pressure differential from the bonnet section to the adjacent pipe in both directions shall be equipped with self relieving seals.  Valves ANSI Class 900 and above shall have ring joint faced flanges in accordance with ASME B16.20 Ring-Joint Gaskets and Grooves for Steel Pipe Flanges unless otherwise indicated.

Vent and drain valves shall comply with the requirements of the valve classification tables and shall be adequate for the pressure and temperature limits indicated on the material and service classification data sheets.

Valve pressure-class ratings shall be in accordance with ASME 16.5.

For testing of valves, API standard 598, Valve Inspection and Test, or API specification 6D, Pipeline Valves, shall be used as a basis.

Unless otherwise specified on the piping material classification data sheets, gate valves shall be outside screw and yoke (OS&Y) with a rising stem, a bolted bonnet, a bolted packing gland, and a solid wedge gate.

If resilient seat inserts are used, the inserts shall be capable of withstanding the maximum temperature encountered in the service application.  Teflon or reinforced Teflon seat insert is preferred.

Valve seats and seals in service ASME Class 900 rating and above shall be specified explosive decompression resistant.

In general reduced bore isolation valves shall be used in all except the following circumstances:

a.     Manifold valves.

b.    Piggable lines.

c.     Pump suctions.

d.    On drain lines subject to potential blockage.

e.     Where the bore velocity would cause unacceptable pressure loss, noise, erosion, or exceed supplied specified limits for corrosion inhibitor film stability

The valve stem shall not be retained by the packing gland.  A shouldered stem with bottom entry is preferred.

The sealing characteristics of ball valves shall not be impaired by rapid temperature changes or in throttling application.

The following restrictions apply to ball valves installed by socket welding or seal welding:

a.     Installation of ball valves by socket welding, seal welding and stress relieving shall not damage the valve seats.

b.    For all socket weld valves disassembly during the installation will be required.

Check valves other than the check valves listed in the piping material classification data sheets may be required for certain service conditions as given below.

Piping Sizes	Check Valves
2 Inches and smaller	Lift type (ball, piston or disc)
3 Inches and larger	Spring actuated, double flapper type

a.     In services with fluids moving at high velocities or with pulsating vapour flows, piston check valves shall be used.

b.    In severe service applications, non-slam check valves with hydraulic (or another type) damping devices shall be used. Lines 8 inches and larger in services that do not require non-slam devices may use spring-actuated double-flapper type check valves.

c.    Centrifugal pump discharge check valves shall be of either the lift disc; balanced tilting-disc or spring actuated double-flapper type

Check valves shall be provided with drains on the downstream side of the check if required for safe operation and maintenance.

Wafer type check valves may be used as an option to flanged swing check valves in ANSI Class 600 and lower.  Wafer check valves shall be designed to API Std 594, Wafer and Wafer-Lug Check Valves.

Butterfly valves shall be limited to water and air service.  Wafer lug and wafer drop-in type butterfly valves shall normally be used.  Butterfly valves shall be designed to API Std 609, Lug and Wafer Type Butterfly Valves.