API 6A - 3 Terms, Definitions and Abbreviated Terms

 go to API 6A - Contents

3.1 TERMS AND DEFINITIONS    
For the purposes of this document, the following terms and definitions apply.

• 3.1.1 acceptance criteria : defined limits placed on characteristics of materials, products or services
• 3.1.2 accessible wetted surface : wetted surface for purposes of non-destructive examination that can be viewed by direct line of sight . NOTE This excludes test ports, control line ports, lockdown screw holes and other penetrations of these types.
• 3.1.3 actuator: mechanism for the remote or automatic operation of a valve or choke
• 3.1.4 adapter: pressure-containing piece of equipment having end connections of different nominal sizes and/or pressure ratings, used to connect other pieces of equipment of different nominal sizes and/or pressure ratings
• 3.1.5 annular pack-off: mechanism that seals off annular pressure between the outside diameter of a suspended tubular member or hanger and the inside diameter of the head or spool through which the tubular member passes or hanger is suspended
• 3.1.6 as-shipped condition: condition of the product or equipment when it is ready for shipment
• 3.1.7 back-pressure valve : unidirectional or bidirectional check valve that is installed through the christmas tree, into the tubing hanger, and prevents well fluids from flowing out of the well
• 3.1.8 blind flange : flange with no centre bore, used to close off completely a flanged end or outlet connection
• 3.1.9 body: any portion of wellhead and christmas tree equipment between end connections, with or without internal parts, which contains well-bore pressure
• 3.1.10 bonnet: pressure-containing closure for a body, other than an end or outlet connection
• 3.1.11 bottom casing pack-off : mechanism that seals off annular pressure between the outside diameter of a suspended tubular member or hanger and the inside diameter of the spool or tubing-head adapter placed over the suspended tubular or hanger
• 3.1.12 bullplug: pressure-containing closure for a female-threaded end or outlet connection, which may have an internal counterbore and/or test port
• 3.1.13 calibration: comparison and adjustment to a standard of known accuracy
• 3.1.14 carbon steel: alloy of carbon and iron containing a maximum of 2 % mass fraction carbon, 1,65 % mass fraction manganese, and residual quantities of other elements, except those intentionally added in specific quantities for deoxidation (usually silicon and/or aluminium)
• 3.1.15 casing: pipe run from the surface and intended to line the walls of a drilled hole
• 3.1.16 casing hanger mandrel: mechanism used to support a casing string in a casing head by means of a male or female thread attached to the casing
• 3.1.17 casing-head housing: equipment attached to the uppermost end of the surface casing, which serves to suspend and seal a casing string
• 3.1.18 casing-head spool: equipment attached to another casing head, which serves to suspend and seal a secondary casing string
• 3.1.19 casting, noun: object at or near finished shape obtained by solidification of a fluid substance in a mould. NOTE HIP components are not considered to be a casting.
• 3.1.20 certificate of compliance: document containing the statement by the manufacturer, or repairer/remanufacturer certifying that the equipment, repair, rework or remanufacture meets the requirements of this International Standard
• 3.1.21 certificate of conformance: document certifying that the repaired/remanufactured equipment and all of its component parts meet the requirements of the original product definition
• 3.1.22 check valve: valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction
• 3.1.23 chemical analysis: determination of the chemical composition of material
• 3.1.24 choke: equipment used to restrict and control the flow of fluids
• 3.1.25 choke bean, flow bean: replaceable orifice part used in positive chokes to control flow rate
• 3.1.26 choke trim: pressure-controlling choke component, including choke beans, used to control or regulate the flow of fluids
• 3.1.27 christmas tree: assembly of equipment, including tubing-head adapters, valves, tees, crosses, top connectors and chokes attached to the uppermost connection of the tubing head, used to control well production
• 3.1.28 clamp hub: protruding rim with an external angled shoulder and a sealing mechanism used to join pressure-containing equipment
• 3.1.29 closure bolting: threaded fastener used to assemble well-bore pressure-containing parts or join end or outlet connections. EXAMPLES Studs, nuts, bolts and capscrews.
• 3.1.30conformance: compliance with specified requirements
• 3.1.31 corrosion-resistant alloy, CRA: nonferrous-based alloy in which any one or the sum of the specified amount of the elements titanium, nickel, cobalt, chromium, and molybdenum exceeds 50 % mass fraction. NOTE This definition is different from that in ISO 15156 (NACE MR0175; see Clause 2).
• 3.1.32 corrosion-resistant ring groove: ring groove lined with a CRA or an austenitic stainless steel to resist metal-loss corrosion
• 3.1.33 cross: pressure-containing fitting with a minimum of four openings
• 3.1.34 cross-over connector: adapter with a restricted-area sealing means and with a top-connection pressure rating above that of the lower connection
• 3.1.35 cross-over flange: double- or single-studded adapter flange with a restricted-area sealing means and with a top-connection pressure rating above that of the lower connection
• 3.1.36 cross-over spool: flanged or other connected equipment with a restricted-area sealing means, at or near the face of its lower flange. NOTE Cross-over spools are also provided with suitable means to suspend and seal around an inner string of casing or tubing. A cross-over spool has a top connection with a pressure rating above that of the lower connection.
• 3.1.37 date of manufacture: date of manufacturer's final acceptance of finished equipment
• 3.1.38 date of repair/remanufacture: date of repairer/remanufacturer's final acceptance of finished equipment
• 3.1.39 end connection, outlet connection: integral male or female thread; clamp hub end connector and flange, studded or through-bolted, or any other means used to join together equipment that contains or controls pressure
• 3.1.40 equipment: any item or assembled equipment to which this International Standard is applicable
• 3.1.41 equivalent round, ER: standard for comparing various shaped sections to round bars, in determining the response to hardening characteristics when heat-treating low-alloy and martensitic corrosion-resistant steel
• 3.1.42 exposed bolting: bolting that is exposed directly to the sour environment or that is buried, insulated, equipped with flange protectors, or otherwise denied direct atmospheric exposure
• 3.1.43 fabrication weld: weld joining two or more parts
• 3.1.44 fit: geometric relationship between parts
• 3.1.45 flange: protruding rim with holes to accept bolts and having a sealing mechanism used to join pressure-containing equipment, with dimensions specified in this International Standard
• 3.1.46 forge, verb: deform metal plastically into desired shapes with compressive force. NOTE Forging is usually a hot process. The use of dies is optional.
• 3.1.47 forging, noun: shaped metal part formed by the forging method
• 3.1.48 form: essential shape of a product including all its component parts
• 3.1.49 full-bore valve: valve whose closure mechanism has a bore dimension the same as or larger than the valve body
• 3.1.50 function: operation of a product during service
• 3.1.51 gate valve: valve assembly with a gate operating within the body, 90° to the conduit, to effect a closure
• 3.1.52 hanger mandrel: portion of a casing or tubing hanger that is attached by a threaded connection to the tubular string and forms the upper end of that tubular string
• 3.1.53 heat: material originating from a final melt, or for remelted alloys, the raw material originating from a single remelted ingot
• 3.1.54 heat-treat lot: 〈batch furnaces〉 material placed on loading or carry devices and moved as a batch through one heat treat cycle
• 3.1.55 heat-treat lot: 〈continuous furnaces〉 group of pieces of material with the same nominal size that is moved sequentially through the heat treatment process using the same process parameters
• 3.1.56 heat treatment, heat treating: specified, timed sequence of controlled heating and cooling of materials for the purpose of changing physical or
• mechanical properties
• 3.1.57 heat-affected zone, HAZ: portion of the base metal that has not been melted, but whose mechanical properties or microstructure has been altered by the heat of welding or cutting
• 3.1.58 heat-sensitive lock-open device: device installed on a surface safety valve (SSV) actuator to maintain the SSV valve in a full open position until exposed to sufficient heat to cause the device to release and allow the SSV valve to close
• 3.1.59 hold period: period of time that the product is subjected to pressure and isolated from the pressure source
• 3.1.60 hot isostatic pressing, HIP: special forming process used to compact and metallurgically bond metal powder. NOTE This process takes place within a flexible, metal container whose contents are formed into the desired shape by subjecting the container to high temperature and pressure in an autoclave. It Produces a fully wrought structure.
• 3.1.61 hot-work: deform metal plastically at a temperature above the recrystallization temperature
• 3.1.62 job-lot traceability: ability to trace parts as originating from a job lot that identifies the included heat(s)
• 3.1.63 linear indication: surface NDE indication whose length is equal to or greater than three times its width
• 3.1.64 lock screw, tie-down screw: threaded pin extending through the wall of a casing-head or tubing-head connection used to lock down hangers or energize seals
• 3.1.65 loose connector: connector, as-manufactured, that is not intended to be made integral with another piece of wellhead and christmas tree equipment. EXAMPLES There are blind, threaded, spacer, welding neck, flanged, studded, or other loose connectors.
• 3.1.66 loose flange: flange, as-manufactured, that is not intended to be made integral with equipment compliant to this International Standard. EXAMPLES Types of flanges include blind, threaded, spacer, welding neck, studded or other connected adapter flanges.
• 3.1.67 low-alloy steel: steel containing less than 5 % mass fraction total alloying elements, or steels with less than 11 % mass fraction chromium, but more than that specified for carbon steel
• 3.1.68 make-and-break, verb: connect and disconnect a connection
• 3.1.69 manufacturing operation: activity involving, but not limited to, the machining, welding, heat treating or other processes utilized to produce a finished product
• 3.1.70 master valve: lowermost valve on the vertical bore of the christmas tree. NOTE Upper master valves and lower master valves are in general use. Upper master valves are sometimes called surface safety valves.
• 3.1.71 material performance: capabilities that it is necessary to demonstrate, as a minimum, for material to satisfy the criteria of this International Standard
• 3.1.72 multistage cross-over spool: flanged or other connected equipment with more than one restricted-area sealing means to provide suitable capability to suspend and seal around multiple inner strings of casing or tubing at several stages. NOTE A multistage cross-over spool may have a top connector with a pressure rating above that of the lower connector.
• 3.1.73 non-exposed bolting: bolting that is not directly exposed to sour environments and is not intended to be buried, insulated, equipped with flange protectors, or otherwise denied direct atmospheric exposure
• 3.1.74 non-pressure-containing weld: weld whose absence does not reduce the pressure-containing integrity of the part
• 3.1.75 objective evidence: documented field experience, test data, publications, finite element analysis or calculations that confirm performance characteristics, as applicable
• 3.1.76 original product definition: complete definition of the requirements for the original assembled equipment, single equipment unit, or component part, including specified limits and tolerances, health, safety and environmental requirements, limitations of use, customer specific requirements, design acceptance criteria, materials of construction, materials processing requirements and physical properties, physical dimensions, and requirements for manufacturing process controls, inspection, assembly and testing, marking, handling, storage, maintenance, and records requirements
• 3.1.77 part: individual piece used in the assembly of single equipment units. EXAMPLES Body, bonnet, gate, stud, handwheel, etc., are parts of a valve. A part may also be a piece not in finished form.
• 3.1.78 plug valve: valve assembly with a plug permanently mounted across the conduit so that, when rotated 90°, it effects a closure. EXAMPLES Plugs may be straight, tapered, ball, etc.
• 3.1.79 post-weld heat treatment: any heat treatment subsequent to welding, including stress relief
• 3.1.80 pressure integrity: structural and leak-resistant capability of a product to contain applied pressure
• 3.1.81 pressure-boundary penetration: device that penetrates directly into or communicates with the well-bore and is not defined elsewhere in this International Standard. EXAMPLES Grease or sealant injection fitting; check valve; control, test or gauge port plug and fitting, needle valve on test, gauge or injection port; electric and control line penetration.
• 3.1.82 pressure-containing part: part whose failure to function as intended results in a release of retained fluid to the atmosphere. EXAMPLES Bodies, bonnets, one-piece stems, and that segment of multi-piece stems that passes through the pressure boundary, are pressure-containing parts.
• 3.1.83 pressure-containing weld: weld whose absence reduces the pressure-containing integrity of the part
• 3.1.84 pressure-controlling part: part intended to control or regulate the movement of pressurized fluids. EXAMPLES Valve-bore sealing mechanisms, choke trim and hangers.
• 3.1.85 primary equipment: pieces of equipment that cannot normally be isolated from well fluid or well pressure
• 3.1.86 prolongation: extension of a piece of raw material or an extension of a production part made integrally during forging, hot working, cold working or casting
• 3.1.87 proration bean: type of positive choke bean of fixed length used to regulate the flow of fluid from a well. NOTE Proration is a system of allocating the amount of oil or gas a well or field is allowed to produce within a given period by a regulatory agency.
• 3.1.88 qualified personnel: individual with characteristics or abilities gained through training, experience, or both, as measured against the established requirements of the manufacturer/purchaser/this International Standard
• 3.1.89 rated working pressure: maximum internal pressure that the equipment is designed to contain and/or control
• 3.1.90 record, noun: retrievable information
• 3.1.91 reduced-opening valve: valve with either a regular or Venturi-type opening, either circular or non-circular, through the closure mechanism
• 3.1.92 relevant indication: surface-rupture NDE indication with major dimensions greater than 1,6 mm (1/16 in). NOTE Inherent indications not associated with a surface rupture are considered non-relevant.
• 3.1.93 remanufacture: activity involving disassembly, reassembly and testing of wellhead and christmas tree equipment, with or without the replacement of parts other than bodies, where machining, welding, heat treating or other manufacturing operations are employed. NOTE Remanufacture does not include the replacement of bodies.
• 3.1.94 repair: activity involving disassembly, reassembly and testing of wellhead and christmas tree equipment with or without the replacement of parts other than bodies. NOTE Repair does not include machining, welding, heat treating, other manufacturing operations or the replacement of bodies.
• 3.1.95 repair level: level to which equipment will be repaired or remanufactured in compliance with this International Standard
• 3.1.96 repairer/remanufacturer: principal agent in the repair and remanufacture of wellhead and christmas tree equipment who chooses to be in compliance with this International Standard
• 3.1.97 replacement part: part used to repair/remanufacture a piece of equipment that meets the wellhead and christmas tree requirement for the applicable repair/remanufacture level
• 3.1.98 restricted-area sealing means, restricted-area pack-off: pack-off or other device used to isolate an area at higher pressure from one at lower pressure. NOTE This device serves to limit pressure-induced loads on connectors or areas of a lower pressure rating. It may also be a seal that encloses a pressure-containment area smaller than the adjacent ring gasket or connector seal.
• 3.1.99 retained fluid: actual fluid produced by a well or injected into a well
• 3.1.100 room temperature: any temperature between 4 °C and 50 °C (40 °F and 120 °F)
• 3.1.101 rounded indication: surface NDE indication that is circular or elliptical, having a length less than 3 times its width
• 3.1.102 running tool: tool used to run, retrieve, position or connect wellhead equipment remotely from the drill floor
• 3.1.103 sandy service: intended for use in wells where particulates such as sand can be expected to cause equipment failure
• 3.1.104 secondary equipment: piece of equipment that can normally be isolated from the well fluid or well pressure
• 3.1.105 serialization: assignment of a unique code to individual parts and/or pieces of equipment to maintain records
• 3.1.106 slip-type casing hanger: mechanism used to support a casing string in a casing head by gripping the pipe with wedge-type members
• 3.1.107 spacer : pressure-containing piece of equipment used to connect and provide separation between other pieces of equipment
• 3.1.108 SSV actuator, underwater safety valve actuator, USV actuator: device which causes the SSV/USV valve to open when power is supplied and to close automatically when power is lost or released
• 3.1.109 SSV valve, USV valve: portion of the SSV/USV that contains the wellstream and shuts off flow when closed
• 3.1.110 stainless steel: steel containing more than 11 % mass fraction chromium to render the steel corrosion-resistant. NOTE Other elements may be added to secure special properties.
• 3.1.111 stress relief: controlled heating of material to a predetermined temperature for the purpose of reducing any residual stresses after welding
• 3.1.112 stress-corrosion cracking: cracking that results from a combination of corrosion and stress
• 3.1.113 studded connection: flanged end or outlet connection in which thread-anchored studs screwed into tapped holes replace the holes for bolt studs
• 3.1.114 substantive change: change identified by the manufacturer that affects the performance of the product in the intended service
• 3.1.115 sulfide stress cracking: cracking of metallic materials due to exposure to fluid containing hydrogen sulfide
• 3.1.116 surface safety valve, SSV: automatic wellhead valve assembly that closes upon loss of power supply. NOTE Where used in this International Standard, the term is understood to include an SSV valve and SSV actuator.
• 3.1.117 swab valve, crown valve: uppermost valve on the vertical bore of the christmas tree above the flowline outlet
• 3.1.118 tee: pressure-containing fitting with three openings. NOTE Two openings opposite one another form the run portion of the tee, and one opening is at 90° to the line of the run. Tees may be equipped with threads, flanges, studs or other end connectors.
• 3.1.119 test agency: independent third party that provides a test facility and administers a testing programme that meets the class II SSV/USV valve-validation testing requirements of Annex I of this International Standard and API Spec 6AV1
• 3.1.120 test and gauge connection: hole drilled and tapped into wellhead and christmas tree equipment through which internal pressure can be measured or through which pressure can be applied to test the sealing mechanisms
• 3.1.121 test tool: tool used to run into the wellhead in order to perform a pressure test
• 3.1.122 thread protector: cap or insert used to protect threads and seals during handling, transportation and storage
• 3.1.123 threaded flange: flange having a sealing face on one side and a female thread on the other for the purpose of joining flanged connections to threaded connections
• 3.1.124 top connector, bottomhole test adapter: uppermost fitting of a christmas tree which allows full-bore access to the christmas tree
• 3.1.125 tubing: retrievable pipe placed within a well to conduct fluid from the well's producing formation into the christmas tree or to conduct kill or treatment fluids in a well. NOTE Tubing is distinguished from casing as being retrievable during the life of the well.
• 3.1.126 tubing hanger mandrel: mechanism used to support a tubing string in a tubing head by means of a male or female thread attached to the tubing
• 3.1.127 tubing-head adapter: equipment that adapts the uppermost connection of a tubing head to the lowermost valve of the christmas tree
• 3.1.128 tubing-head spool: piece of equipment attached to the uppermost casing head or smallest casing string which serves to suspend the tubing and to seal the annular space between the tubing and casing
• 3.1.129 underwater safety valve, USV: automatic valve assembly installed at an underwater wellhead location which closes on loss of power supply. NOTE Where used in this International Standard, the term is understood to include a USV valve and USV actuator.
• 3.1.130 valve-bore sealing mechanism: internal valve parts that close off the flow through the valve bore. EXAMPLES Gates, balls, plugs, poppets, flappers and their respective seats.
• 3.1.131 valve-removal plug: threaded plug that can be installed in the wellhead to enable gate-valve removal under pressure
• 3.1.132 Venturi valve: valve with a reduced opening, in which the transformation from the full-opening ends to the reduced-closure area is well streamlined to reduce pressure loss
• 3.1.133 visual examination: examination of parts and equipment for visible defects in material and workmanship
• 3.1.134 volumetric non-destructive examination, volumetric NDE: examination for internal material defects by methods such as radiography and/or ultrasonic testing
• 3.1.135 wear bushing: retrievable cylindrical device that protects the internal surfaces of wellhead equipment and the top of the last casing suspended
• 3.1.136 weld preparation: geometry of surfaces for the purpose of welding
• 3.1.137 weld, verb: fuse materials, with or without the addition of filler materials
• 3.1.138 welding neck flange: flange with a neck on the side opposite the sealing face, prepared with a bevel to weld to corresponding pipe or transition pieces
• 3.1.139 wellhead: all permanent equipment between the uppermost portion of the surface casing and the tubing-head adapter connection
• 3.1.140 wetted surface: any surface that has contact with pressurized well fluid, either by design or because of internal seal leakage
• 3.1.141 wing valve: valve located on the christmas tree, but not in the vertical run, which can be used to shut off well flow
• 3.1.142 wrought product: product made from material having a wrought structure
• 3.1.143 wrought structure: structure that contains no cast dendritic elements
• 3.1.144 yield strength: stress level, measured at room temperature, at which material plastically deforms and does not return to its original dimensions when the load is released. NOTE All yield strengths specified in this document are the 0,2 % offset yield strength in accordance with ISO 6892-1 or ASTM A370.

3.2 ABREVIATED TERMS 
For the purposes of this document, the following abbreviated terms apply.

• AQL acceptable quality level
• CRA corrosion-resistant alloy
• DAC distance amplitude curve
• ER equivalent round
• FEA finite element analysis
• HAZ heat-affected zone
• HBW Brinell hardness
• HIP hot isostatic pressing
• HRB Rockwell hardness scale B
• HRC Rockwell hardness scale C
• NDE non-destructive examination
• NPT national pipe thread
• OEC other end connection
• PQR procedure qualification record
• PR performance requirement
• PSL product specification level
• QTC qualification test coupon
• RMS root mean square
• RL repair/remanufacture level
• Rm ultimate tensile strength
• ROE radius of exposure
• SSV surface safety valve
• TC test coupon
• UNS unified numbering system
• USV underwater safety valve
• WPQ welder performance qualification
• WPS welding procedure specification

 go to API 6A - Contents

API 6A - 1. Scope

go to API 6A - Contents

   

1.1. PURPOSE :                                                                                          

• specifies requirements and gives recommendations for the performance, dimensional and functional interchangeability, design, materials, testing, inspection, welding, marking, handling, storing, shipment, purchasing, repair and re-manufacture of wellhead and christmas tree equipment for use in the petroleum and natural gas industries.
• not apply to field use, field testing or field repair of wellhead and christmas treeequipment.

1.2. APPLICABILITY (see the typical equipment in Figures 1 and 2 below)

1. wellhead equipment: casing-head housings, casing-head spools, tubing-head spools, cross-over spools, multi-stage head housings and spools;
2. connectors and fittings: cross-over connectors, tubing-head adapters, top connectors, tees and crosses, fluid-sampling devices, adapter and spacer spools;
3. casing and tubing hangers: mandrel hangers, slip hangers;
4. valves and chokes: single valves, multiple valves, actuated valves, valves prepared for actuators, check valves, chokes, surface and underwater safety valves and actuators, back-pressure valves;
5. loose connectors [flanged, threaded, other end connectors (OEC), and welded]: weld neck connectors, blind connectors, threaded connectors, adapter and spacer connectors, bullplugs, valve-removal plugs;
6. other equipment:  actuators, clamp hubs, pressure boundary penetrations, ring gaskets, running and testing tools  (see Annex H), wear bushings (see Annex H).

1.3. SERVICE CONDITIONS : This International Standard defines service conditions, in terms of pressure, temperature and material class for the well-bore constituents, and operating conditions.

1.4. PRODUCT SPECIFICATION LEVELS (PSL): PSL 1, 2, 3, 3G, and 4 define the different levels of technical quality requirements. Annex A provides guidelines (not requirements) for selecting an acceptable PSL.

go to API 6A - Contents

API Spec 6A 20th Edition

ANSI/API SPECIFICATION 6A
20th Edition, October 2010, Effective Date 1-April-2011
Specification for Wellhead and Christmas Tree Equipment

CONTENTS

1. Scope
2. Normative References
3. Terms, Definitions And Abbreviated Terms
4. Design and performance - General requirements
5. Materials - General requirements 
6. Welding - General requirements
7. Quality control
8. Equipment marking
9. Storing and shipping
10. Equipment-specific requirements 
11. Repair and re-manufacture 

SUMMARY

1.1	PURPOSE specifies requirements and gives recommendations for the performance, dimensional and functional interchangeability, design, materials, testing, inspection, welding, marking, handling, storing, shipment, purchasing, repair and re-manufacture of wellhead and christmas tree equipment for use in the petroleum and natural gas industries. not apply to field use, field testing or field repair of wellhead and christmas treeequipment.
1.2	APPLICABILITY wellhead equipment: casing-head housings, casing-head spools, tubing-head spools, cross-over spools, multi-stage head housings and spools; connectors and fittings: cross-over connectors, tubing-head adapters, top connectors, tees and crosses, fluid-sampling devices, adapter and spacer spools; casing and tubing hangers: mandrel hangers, slip hangers; valves and chokes: single valves, multiple valves, actuated valves, valves prepared for actuators, check valves,chokes, surface and underwater safety valves and actuators, back-pressure valves; loose connectors [flanged, threaded, other end connectors (OEC), and welded]: weld neck connectors, blind connectors, threaded connectors, adapter and spacer connectors, bullplugs, valve-removal plugs; other equipment:  actuators, clamp hubs, pressure boundary penetrations, ring gaskets, running and testing tools (see Annex H), wear bushings (see Annex H).
1.3	Service Conditions: This International Standard defines service conditions, in terms of pressure, temperature and material class for the well-bore constituents, and operating conditions.
1.4	Product Specification Levels (PSL): PSL 1, 2, 3, 3G, and 4 define the different levels of technical quality requirements. Annex A provides guidelines (not requirements) for selecting an acceptable PSL.
4.1	Performance Requirements : para 4.2 to 4.7 and Clause 10 (P & T ranges and used, test fluids consistent with the material class in Table 3). Other requirements specified by the purchaser may include load capability, cycles, lubrication and operating force or torque. Performance requirement levels: PR1 and PR2.
4.2	4.2 Service conditions 4.2.1 Pressure Ratings : maximum rated working pressures (ksi: 2, 3, 5, 10, 15, 20),  threaded connection limitation (limited by thread sizes and rated working pressures in Table 1 -- rating do not include tubing and casing hangers) 4.2.2 Temperature Ratings : min. (the lowest ambient temperature to which the equipment may be subjected) and max. (the highest temperature of the fluid that may directly contact the equipment) temperatures specified in Table 2 or as agreed between the purchaser and manufacturer. 4.2.3 Material Classes : designed with materials, including metallics, that meet the requirements set forth in Table 3 class AA: stainless steels and/or CRA materials and classes BB: carbon and low-alloy steels material classes DD, EE, FF and HH shall meet ISO 15156 (all parts) (NACE MR0175; see Clause 2) -->  the designation and marking the maximum allowable partial pressure of H2S in units consistent with the rated working pressure markings and prefixes example, “FF-10” :indicates material class FF rated at 10 kPa H2S maximum allowable partial pressure. Where no H2S limit is defined by ISO 15156 (all parts) (NACE MR0175; see Clause 2) for the partial pressure, “NL” shall be used for marking (i.e. “DD-NL”). resistance to cracking caused by H2S is influenced by a number of other factors: pH; temperature;  chloride concentration; elemental sulfur. material classes ZZ : a specific sour-service application that is outside the parameters defined in ISO 15156 (all parts) (NACE MR0175; see Clause 2). The manufacturer shall meet material specifications supplied or approved by the purchaser, and shall maintain traceable records (regardless of PSL).
4.3	Design methods4.3.1 Connections: Flanges, Clamp hub and outlet end connections, Clamps 4.3.2 Casing hangers, tubing hangers, back-pressure valves, lock screws and stems4.3.3 Other end connectors, bodies and bonnets 4.3.3.5 Design qualification by proof test: as an alternative to the analytical methods above, the pressure rating of equipment may be determined by the use of a hydrostatic test at elevated pressure. It shall not previously have been subjected to a pressure greater than 1,5 times the desired or anticipated maximum allowable working pressure.
4.3
.
.
.
.
.
.
.
.
.
.
.
.
.
.	.
.
.

 asd