The purchaser may specify other types of connections, such as welded or flanged. Threads shall be either tapered and capable of providing a pressure-tight seal or parallel-threaded. Connections or plugs with parallel threads shall have a head section for trapping and retaining a sealing member suitable for the specified valve service. Thread sizes shall be in accordance with Table 7.
Table 7 - Thread sizes for bypass, drain and vent connections. Wrenches for valves shall either be of an integral design or consist of a head which fits on the stem and is designed to take an extended handle.
The head design shall allow permanent attachment of the extended section if specified by the purchaser. The maximum force required at the handwheel or wrench to apply the breakaway torque or thrust shall not exceed N.
Wrenches shall not be longer than twice the face-to-face or end-to-end dimension of the valve. Handwheel diameter s shall not exceed the face-to-face or end-to-end length of the valve or 1 O00 mm, whichever is the smaller, unless otherwise agreed. Except for valve sizes DN 40 NPS 1 ' 1 2 and smaller, spokes shall not extend beyond the perimeter of the handwheel unless otherwise agreed. When specified by the purchaser, the handwheel of the gearbox input shaft shall be provided with a torque-limiting device, such as a shear pin, to prevent damage to the drive train.
Valves shall be supplied with locking devices if specified by the purchaser. Locking devices for check valves shall be designed to lock the valve in the open position only. Valves fitted with manual or powered actuators shall be furnished with a visible indicator to show the open and the closed position of the obturator.
Misalignment or improper assembly of components shall be prevented by suitable means, such as a dowel pin or fitting bolt, which ensure the unique location of manual or powered operators and stem extension assemblies. External connections shall be sealed, for example with gaskets or O-rings, to prevent external contaminants entering the mechanism. Operators and stem extension assemblies shall be provided with a means of preventing pressure build-up in the mechanism resulting from stem or bonnet seal leakage.
The interface between actuators and valve bonnet or stem extension assemblies shall be designed to prevent misalignment or improper assembly of the components. The interface between actuators and valve bonnet or stem extension assemblies shall be sealed with gaskets or O-rings to prevent external contaminants from entering the assembly.
Means shall be provided of preventing pressure build-up in the actuator from stem or bonnet seal leakage. The output of the actuator shall not exceed the maximum load capacity of the valve drive train. The design thrust or torque for all drive train calculations shall be at least two times the breakaway thrust or torque.
NOTE This factor of safety is to allow for thrust or torque increase in service due to infrequent cycling, low-temperature operation and the adverse effect of debris. For ball valves, the total torsional deflection of the extended drive train when delivering the design torque shall not exceed the overlap contact angle between the seat and obturator.
Deflections of the extended drive train shall not prevent the obturator from reaching the fully closed position. If specified by the purchaser, fire resistance certification of the design shall be provided, in accordance with clause A.
If specified by the purchaser, valves shall be provided with an anti-static device and tested in accordance with clause C. Design documentation shall be reviewed and verified by competent personnel other than the person who performed the original design.
Specificationsfor metallic parts shall, as a minimum, specify the requirements for:. All process-wetted parts, metallic and non-metallic,and lubricants shall be suitable for the commissioning fluids and service specified by the purchaser.
Non-metallic parts of valves intended for hydrocarbon gas service at pressures of PN Class or above shall be resistant to explosive decompression. The CE shall be calculated in accordance with the following formula:. The chemistry of austenitic stainless steels for welding ends shall meet the following requirements:. Requirements for the chemistry of welding ends made of other materials shall be established by agreement.
A minimum of one impact test, comprising a set of three specimens, shall be performed on a representative test bar of each heat of the material in the final heat-treated condition. Test specimens shall be cut from a separate or attached block taken from the same heat, reduced by forging where applicable, and heat-treated in the same heat treatment batch, including stress-relieving, as the product materials except that: - pressure-containing parts stress-relieved at or below a previous stress-relieving or tempering temperature need not be retested; - retesting is not required after stress-relieving if the measured toughness of the material before stress-relieving is three times the required toughness.
Toughness testing may be performed during the qualification of the valve manufacturing procedure provided that the material for testing is heat-treated using the same equipment as during valve production. The impact test temperature shall be as defined in the applicable material specifications and pipeline design standardhode. Except for material for bolting, impact test results for full-size specimens shall meet the requirements of Table 8.
Table 8-Charpy V-notch impact requirements full-size specimen. Bolting material with a mechanical strength above ASTM A Grade B7 or hardness exceeding HRC22 shall not be used for valve applications where hydrogen embrittlement may occur, unless otherwise agreed. For example, hydrogen embrittlement can occur in buried pipelines with cathodic protection. Materials for pressure-containing and pressure-controlling parts and bolting shall meet the requirements of NACE MR if sour service is specified.
Welding, including repair welding, of pressure-containing and pressure-controlling parts shall be performed in accordance with procedures qualified to ASME Section IX or EN , and 8.
The results of all qualification tests shall be documented in a procedure qualification record PQR. Post-weld heat treatment PWHT shall be performed in accordance with the relevant material specification. NOTE Some pipeline-welding standards, such as BS , may have more stringent requirements for the essential variables of welding.
It may be necessary to provide full weld test rings, in the same heat treatment condition as the finished valve, for weld procedure qualification. A set of three weld metal impact specimens shall be taken from the weld metal WM at the location shown in Figure The specimens shall be oriented with the notch perpendicular to the surface of the material. A set of three impact specimens shall be taken from the heat-affected zone HAZ at the location shown in Figure The notch shall be placed perpendicularly to the material surface at a location resulting in a maximum amount of HAZ material located in the resulting fracture.
Specimens shall be etched to determine the location of the notch. The impact test temperature for welds and heat-affected zones shall be at or below the minimum design temperature specified for the valve.
Hardness testing shall be carried out for the qualification of procedures for welding on pressure-containing and pressure-controlling parts in valves required to meet NACE MR Figure Charpy V-notch weld metal WM specimen location. Key 1 Weld metal 2 Heat-affected zone 3 Base metal. Figure Hardness survey specimen location. This clause specifies the quality control requirements for the manufacturing of valves.
The purchaser shall specify which particular supplementary NDE requirements in Annex B shall be performed. Equipment for measuring dimensions shall be controlled and calibrated in accordance with methods specified in documented procedures. After defect removal, the excavated area shall be examined by magnetic particle MT or liquid penetrant PT methods prior to starting repair welding. Repair welds on pressure-containing parts shall be examined using MT or PT methods. Acceptance criteria shall be specified in documented procedures.
The supplementary NDE requirements in Annex B, if specified by the purchaser, shall also apply to repair welding. Each valve shall be tested in accordance with this clause prior to shipment. The purchaser shall specify which particular supplementary tests in Annex C shall be performed, together with the frequency of testing. Testing shall be performed in the sequence used in this clause for specifying the test requirements.
Shell pressure testing shall be carried out before painting of the valves. Test fluids shall be fresh water which may contain a corrosion inhibitor and, by agreement, antifreeze. Valves shall be tested with the seating and sealing surfaces free from sealant except where the sealant is the primary means of sealing. Tests specified with the valve half-open may also be performed with the valve fully open provided the body cavity is simultaneously filled and pressurized through a cavity connection.
Unless otherwise agreed, stem backseat testing shall be performed prior to shell testing. Where a valve has a stem backseat feature, testing of the backseat shall commence with the seat free.
Self- energized packing or seals shall be removed unless a test port is provided for this test. The valves shall be filled with the ends closed off and the obturator in the partially open position until leakage of the test fluid around the stem is observed. The backseat shall then be closed and a minimum pressure of 1,Itimes the pressure rating determined in accordance with 6.
Monitoring for leakage shall be through a test access port or by monitoring leakage around the loosened packing. Table 9-Minimum duration of stem backseat tests. Hydrostatic shell testing shall be performed on the fully assembled valve prior to painting. Valves shall be closed off and the obturator placed in the partially open position during the test. If specified by the purchaser, the method of closing the ends shall permit the transmission of the full-pressure force acting on the end blanks to the valve body.
Where present, external relief valves shall be removed and their connections plugged. The test pressure shall be 1,5 or more times the pressure rating determined in accordance with 6. The duration shall not be less than that specified in Table IO. Test duration min utes. After hydrostatic shell testing, external relief valves shall be re fitted to the valve. The relief valve connection shall be free of visible leakage during this period. Where provided, the external relief valve shall be set to relieve at the specified pressure and tested.
The set pressure of relief valves shall be between 1, I and 1,33 times the valve pressure rating determined in accordance with 6. High-pressure gas seat testing in accordance with clause C. Lubricants shall be removed from seats and obturator sealing surfaces except, by agreement, for assembly lubricants for metal-to-metal contact sufaces.
The test pressure for all seat tests shall not be less than 1 , l times the pressure rating determined in accordance with 6. The test duration shall be in accordance with Table Table 1l-Minimum duration of seat tests. Leakage for soft-seated valves and lubricated plug valves shall not exceed I S 0 Rate A no visible leakage.
For metal-seated valves the leakage rate shall not exceed I S 0 Rate D, except that the leakage rate during the seat test in The test procedures for various types of block valve are given in With the valve half-open, the valve and its cavity shall be completely filled with test fluid.
The valve shall then be closed and the test pressure applied to the appropriate end of the valve. Leakage from each seat shall be monitored via the valve body cavity vent or drain connection.
For valves without a body cavity connection, seat leakage shall be monitored from each seat at the respective downstream end of the valve the valve end downstream of the pressurized test fluid. The valve shall then be closed and the test pressure applied successively to both ends of the valve. Seat leakage shall be monitored from each seat via the valve body cavity vent or drain connection. For valves without a body cavity vent or drain connection, seat leakage shall be monitored from the respective downstream end of the valve.
Cavity relief valves shall be removed if fitted. The valve and cavity shall be filled with test fluid, with the valve half- open, until the test fluid overflows through the cavity relief connection. To test for seat leakage in the direction of the cavity, the valve shall be closed.
The test pressure shall be applied successively to each valve end to test each seat separately from the upstream side. Leakage shall be monitored via the valve cavity pressure relief connection. Thereafter, each seat shall be tested as a downstream seat. Both ends of the valve shall be drained and the valve cavity filled with test fluid.
Pressure shall then be applied whilst monitoring leakage through each seat at both ends of the valve. With the valve half-open, the valve and the test cavity shall be completely filled with test fluid until fluid overflows though the valve cavity vent connection.
The valve shall then be closed and the vent valve on the test closure opened to allow fluid to overflow, or the test closure on the downstream end of the valve removed. The test pressure shall then be applied to the upstream end uni-directional seat end and leakage monitored from the cavity connection. If leakage is also occurring through the downstream seat, the upstream seat leakage shall be taken as the sum of the leakage measured from the cavity and the downstream connections.
The test in To test the bi-directional seat in its downstream-sealing direction, both ends of the valve shall be blanked off. With the valve half-open, the valve shall be completely filled with test fluid and pressurized to the test pressure. The test pressure shall be maintained on the cavity connection whilst monitoring seat leakage of the bi-directional seat at the overflow connection on the downstream test closure. The valve shall then be closed and the valve body vent valve opened to allow excess test fluid to overflow from the valve cavity test connection.
The test pressure shall then be applied to one end of the valve and the pressure released at the other end. This test shall be repeated for the other valve end. Seat tightness shall be monitored during each test via overflow from the valve cavity connection. The test pressure shall be applied simultaneously from both valve ends. Valves shall be marked in accordance with Table On valves whose size or shape limits the body markings, they may be omitted in the following order: - size;.
The purchaser may specify requirements for the marking of valve components. For valves with one seat uni-directional and one seat bi-directional only, the directions of both seats shall be specified on a separate identification plate as illustrated in Figure In Figure 15, one symbol indicates the bi- directional seat and the other symbol indicates the uni-directional seat.
Figure Typical identification plate for valve with one seat uni-directional and one seat bi-directional. Table Valve marking Marking Application 1.
On both body and nameplate 2. Pressure class On both body and nameplate 3. PressureAernperature rating On nameplate a Maximum operating pressure at maximum operating temperature b Maximum operating pressure at minimum operating temperature 4.
On nameplate 5. Body material designation: Material symbol, e. On both body and nameplate. Bonnethover material designation: Material symbol e. On bonnetkover [including melt identification e. Trim identification: Symbols indicating material of stem and sealing faces of closure members if different from that of body Nominal valve size On body or nameplate or both where practicable a Full-opening valves: nominal valve size On body or nameplate or both where practicable b Reduced-opening valves: shall be marked as specified in 6.
On body or nameplate or both where practicable 9. Ring joint groove number On valve flange edge 1o. SMYS and minimum wall thickness On body weld bevel ends Flow direction for check valves only On body of uni-directional valves only Seat sealing direction Separate identification plate on valve body Unique serial number On both body and nameplate Date of manufacture month and year On nameplate I S 0 On nameplate.
R49 Item 9: ring joint identification on flange edge Item serial number. Stainless-steel valves shall not be painted unless otherwise agreed. Flange faces, weld bevel ends and exposed stems shall not be painted.
Protective covers shall be made of wood, wood fibre, plastic or metal and shall be securely attached to the valve ends by bolting, steel straps, steel clips or suitable friction-locking devices.
The design of the covers shall prevent the valves from being installed unless the covers have been removed. Plug, ball and reverse-acting through-conduit gate valves shall be shipped in the fully open position, unless fitted with a fail-to-close actuator. Valves provided with stem extensions without an operating mechanism shall have the annular space closed and the stem extension secured against the outer housing. Documentation shall be provided by the manufacturer in legible, retrievable and reproducible form, and free of damage.
Documentation required by this International Standard shall be retained by the manufacturer for a minimum of five years following the date of manufacture.
The purchaser shall specify which particular supplementary documentation requirements in Annex D shall be provided. Annex A i nformat ive. This annex provides guidelines to assist the purchaser with valve type selection and specification of specific requirements when ordering valves. NOTE The maximum test pressure for valves fitted with an external pressure relief may be lower see 6.
High internal pressures can result from the thermal expansion of the fluid trapped in these confined areas. Therefore, if the valve has no self-relieving design provision, pressure relief fittings shall be fitted in the valve body in accordance with 6. The purchaser should examine the valve design for compatibility with pigging operations when ordering valves for use in pipelines requiring pigging. Avalve in which the drive member or the obturator obstructs the bore in the otherwise fully open position e.
Certain full-opening valves with pockets may allow bypass of fluid around a short pig or sphere. The fire resistance design of valves shall be qualified by fire testing in accordance with I S 0 The purchaser shall specify any additional test requirements not covered by this International Standard. The valve data sheet in this annex may be used to assist with the specification of valves for ordering.
Specification required Valve location and function Nominalvalve size Maximum operatingpressure Maximumfield test pressure see clause A.
Yes No Plain raised face or ringjoint? If ringjoint, flat or raisedface? Welding end? Yes No Attach specificationsfor welding-end configuration. Specialflanges or mechanicaljoints?
Length:Any special requirementsfor end-to-end or face-to-face dimension? Valve operation Is gearbox with handwheel required? If so, give details:- For a handwheel on a horizontal shaft, give distance from centreline of valve opening to handwheel: mm Or, for a handwheelon a vertical shaft, give distance from centrelineof valve opening to centre of rim of handwheel: mm Note: For plug valves having loose wrenches, wrenches must be ordered separately.
Wrench required? Lockingdevice required? Yes No Pressure relief: If pressure relief devices are required,are there special requirementsfor these devices? Drain connections:Any requirements? Bypass connections:Any requirements? Supplementary documentationrequired? See Annex D - Third-party witness of processeshesting Painting or coating required? Annex B normat ive. This annex specifies supplementary NDE requirements for the examination of valves which shall be performed by the manufacturer if specified by the purchaser.
The type and severity level for acceptance of the welding ends shall be as specified by the purchaser. Examination shall be carried out in accordance with ASME Section V, Article 23 using the direct technique or, where proper access or interpretation of results is not possible, by shear wave examination. Annex C normat ive. This annex defines requirements for supplementary valve testing which shall be performed by the manufacturer if specified by the purchaser.
The frequency of testing shall also be specified by the purchaser, if not defined in this annex. By agreement, hydrostatic testing may be performed at pressures higher than specified in The seat test specified in The seat tests specified in The test pressure and duration shall be as specified in The resistance shall be measured on dry valves before pressure testing and shall not exceed 10 Q.
The maximum torque or thrust required to operate ball, gate or plug valves shall be measured at the pressure specified by the purchaser for the following valve operations: a open to closed with the bore pressurized and the cavity at atmospheric pressure; b closed to open with both sides of the obturator pressurized and the cavity at atmospheric pressure; c closed to open with one side of the obturator pressurized and the cavity at atmospheric pressure; d as in c but with the other side of the obturator pressurized.
Torque or thrust values shall be measured with seats free of sealant except where the sealant is the primary means of sealing. If necessary for assembly, a lubricant with a viscosity not exceeding that of SAE 1OW motor oil or equivalent may be used. Thrust and torque testing shall be performed following hydrostatic shell testing and, if specified, low-pressure gas seat testing. Cavity relief testing is not required if protection of the cavity against over-pressure is ensured, for both the open and the closed position, by a hole in the obturator or around the seat seal.
Failure to relieve shall be cause for rejection. Evidence of trapped pressurizing medium in the cavity shall be cause for rejection. Process-wetted and pressure-containing parts which are manufactured, fabricated or formed from plate shall be resistant to hydrogen-induced cracking HIC. Annex D n orm ative. The manufacturer shall provide the following supplementary documentation if specified by the purchaser:. D I 1 Calibration records purchaser to identify requirements for equipment when ordering.
D13 Material certification to I S 0 purchaser to specify type of certification, and for which parts, when orde ring. Products stamped with the API Monogram provide observable evidence that they were produced in accordance with a verified quality system and in accordance with an API-recognized, international oil and gas industry product specification.
When used in conjunction with the requirements of the API License Agreement, API Specification Q I Parts One and Two define the program for voluntary licensing of suppliers who wish to provide oil and gas industry products in accordance with an API-recognized international oil and gas industry product specification.
API Monogram Program Licenses are issued only after an on-site audit has verified that the licensee conforms with both the quality system requirements described in API Specification Q I Part One and the requirements of an API- recognized international oil and gas industry product specification.
In addition to the referenced standards listed in Section 2, this Annex references the following standard:. For licensees under the Monogram Program, where cited these requirements are mandatory. Referenced standards used by the manufacturer may be either the applicable revision shown in Section 2 and herein, or the latest revision. The Licensee shall apply the monogram, license number, and date of manufacture to monogrammed products in accordance with a marking procedure as specified by the applicable API product specification.
Where there are no API product specification marking requirements, the licensee shall define the location s where this information is applied. The monogram may be applied at any time appropriate to the manufacturing process but shall be removed if the product is subsequently found to be in nonconformance with API specified requirements. When you are recommissioning a pipeline. Over the recent past, pipelines that were shut down have started being recommissioned.
Since the valves on these industries have been idle for years, there is a need for them to be repaired and tested. When you are fixing spares that have been idle for quite some time.
If you are replacing a valve with a new one that has been sitting outside for more than a year or even through extreme changes of weather, you are advised to test the valves before fixing them into the line. When you are using a valve in a bypass while doing maintenance.
Experts will always put a valve in a bypass pipeline as they do their maintenance on the mainline. In case these bypass valves have been idle for more than a year or rather have been in extreme changes of weather, they should always have a test before they are installed. When you send a valve in order to be repaired.
Any time you have an API valve repaired, maybe since it is leaking or not functioning well, the valve has to be tested again before you put it back into service on your line. API 6D Ball valve has a rounded hollow designed device used for on-and-off service. The ball is always in the path where fluid follows from. It is important to source them from API 6d ball valve manufacturers who prioritize quality over cost. Best quality ball valves will serve the intended purpose for a longer time.
Check valves are majorly used in oil and gas pipelines to prevent any backflow of oil or gas. These check valves have a bolted cover and a clapper that swings freely. The clapper is mainly used to control the flow of fluids in the pipes when turned on and off. API 6D gate valves are customed to use pressure for tight cover on the top side when high pressure occurs.
Internal springs have a sealing of low pressure as they help in pushing seat rings against the gates. API 6D gate valves are ideal in the transportation of gas, and oil products and their valves are made of different types of materials to meet your project needs.
It is important to have pressure valves inspected and tested before they are considered for use.
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