EN comprises 13 pages. Sudarshan Kv. Karthik Raman. Kaushik Sengupta. Nitin Aggarwal. Cesare Daldossi. Anurag Srivastava. Nat Flores. Rafi Udeen. Shankar Raj. Raj Bindas. Javier Barrera. Santiago Toller. Ephrem Woldekidan. More From Josip-Jenny Zrile. Josip-Jenny Zrile. Popular in Law. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October , and conflicting national standards shall be withdrawn at the latest by October This document supersedes EN The main changes compared to the previous edition are: a the scope was specified and editorially revised; b the normative references were updated; c Clause 3 Terms and definitions was revised; d Clause 4 Test requirements was changed; e A.
EN contains supplementary testing requirements for tests, test procedures and acceptance criteria of valves. Tests and procedures given in this European Standard may also be used, if required, for type tests and acceptance tests.
Details should be included in the appropriate standard. The specified tests may also be used as type tests or acceptance tests. Part 1: Pressure tests, test procedures and acceptance criteria. Mandatory requirements. These standards covers both strength test shell pressure test and seat leakage test. It shall be noted that some valve design standards, such as BS and. Test pressures: Test description Low-preesure gas High-pressure liq.
NPS : The maximum permissible leakage rate shall be 3 cm3 per minute per in. September API It shall be mentioned that leakage rates of safety critical valves in service cannot be evaluated against the above mentioned leakage rates.
This valve will require a leakage rate A according to EN Leakage rates The tests are carried out as per Tables 1 to 4 on previous page. The acceptance criteria shall be as follows:.
Unless otherwise specified in the appropriate product standard, when the test fluid is a liquid, leakage from the operating mechanism sealing is permitted provided that there is no visually detectable leakage when the test pressure is 1,1 times the maximum allowable pressure. The test shall confirm the capability of the seat s to conform to the specified leakage rate:. The test fluid shall be a liquid or gas.
If the test fluid is a liquid, avoid entrapped gas. The test procedures to be used for the different types of valves shall be taken from Table A. Type of valve Test procedure Gate valve 1.
Fill the valve cavity including if appropriate, the bonnet cavity with the test fluid. Ball valve 2. Force of closing shall be in accordance to standards dealing with products and fitness Plug valve for purpose. Move the obturator to the closed position. Apply the test pressure specified in A.
Determine the leakage rate. Repeat 3 and 4 inclusive for the other side of the valve. Globe valve 1. Fill the upstream valve cavity with the test fluid. Diaphragm valve 1. Fill the valve cavity with the test fluid. See NOTE 6. Butterfly valve 1. Test double disc butterfly valves either in both directions with the body vent plug removed, or test by introducing the test pressure between the discs via a shell tapping and measuring leakage either side of the disc.
Check valve 1. Fill the downstream valve cavity including, if appropriate, the cover cavity with the test fluid. NOTE 1 The procedure described may not ensure pressurization of the integrate space of double-seated valves and may not therefore permit verification of the leakage rate of the downstream seat.
When such pressurization is a requirement of the product or performance standard, or is required by the purchaser, it may be necessary to carry out step 3 before step 2. NOTE 2 Valves which incorporate "double block and bleed" design features shall have the bleed plug removed prior to the test in order to prove the "double block and bleed" capability. NOTE 3 Valves with double sealing such as two-piece obturator or double-seated valves may be tested by applying the test pressure between the seats and checking each side of the closed valve.
NOTE 4 Soft seated ball valves previously subjected to a liquid seat test pressure may have a reduced performance capability in some subsequent services at low differential pressures. If a liquid seat test pressure is specified and is carried out before a low pressure gas seat test, it may be necessary to allow time for the seat material to recover.
NOTE 5 With plug valves relying on a sealing compound to effect a seal, it is permitted to charge with sealing compound prior to testing. NOTE 6 Valves with symmetrical seating may be tested in either direction. The test pressure shall be maintained for a duration not less than the periods specified in Table A. When the seat tightness is tested in a production line and the time of one production cycle is shorter than the production test time specified in Table A.
The choice of the rate A to G is specified in the relevant valve product standards. The leakage rates measured during the specified test duration shall not exceed the rate specified in the corresponding product or performance standards. The acceptance criteria takes into account the uncertainties measurement.
Leakage rates are given in Table A. NOTE 1 The leakage rates only apply when discharging to room temperature. NOTE 3 "No visually detectable leakage" means no visible weeping or formation of drops or bubbles. If leakage rate measurements are carried out by automatics means, this should be qualified by the manufacturer's quality system. Annex ZA informative. Once this standard is cited in the Official Journal of the European Union under that Directive and has been implemented as a national standard in at least one Member State, compliance with the clauses of this standard given in Table ZA.
Table ZA. ISO , Industrial valves — Pressure testing of metallic valves.
0コメント