MVME177PA-64SE工控備件模塊
對于設(shè)計用于抵抗任何方向的壓力關(guān)閉的閥門（雙截斷和排放閥或截止閥除外），應(yīng)將壓力依次施加到關(guān)閉閥門的每一側(cè)，另一側(cè)向大氣開放，以檢查關(guān)閉裝置大氣側(cè)的泄漏情況。對于截止閥，應(yīng)向一個方向施加壓力，壓力施加在閥盤下方。對于設(shè)計為僅在一個方向上承受壓力時關(guān)閉并標記的閥門，應(yīng)僅在閥門的壓力側(cè)施加壓力。對于止回閥，應(yīng)在下游側(cè)施加壓力。對于配有密封或彈性內(nèi)襯且設(shè)計用于125級或150級法蘭（API 609，A類閥門）的蝶閥，只需在一個方向上進行關(guān)閉試驗。對于其他彈性蝶閥（API 609，B類閥門），需要在兩個方向進行關(guān)閉試驗。對于具有首選流動方向的蝶閥，非首選方向上的關(guān)閉試驗應(yīng)基于該方向上減小的壓差額定值。6.4.4將試驗空氣或氣體截留在一體式（實心或柔性）楔形閘閥閥座之間的體腔內(nèi)，然后用水覆蓋閥座或用肥皂或類似溶液覆蓋閥座，不構(gòu)成可接受的低壓關(guān)閉試驗。
6.4.5如果閥體空腔內(nèi)的螺紋連接允許6.6.1中雙截斷和排放閥所述的測試程序，則該連接應(yīng)符合MSS SP-45的要求，并應(yīng)在裝運前安裝實心管塞（符合ASME B16.11），其材料成分與閥殼的材料成分相同。6.5高壓關(guān)閉試驗高壓關(guān)閉試驗程序應(yīng)與低壓關(guān)閉試驗程序相同，但如果是液體試驗，則應(yīng)在觀察到液滴而非6.4中所述的氣泡時檢測泄漏。6.6雙阻斷和排放高壓關(guān)閉試驗對于雙阻斷和泄放閥，應(yīng)通過閥門端口將壓力依次施加到關(guān)閉件的每一側(cè)。應(yīng)通過閥門底部的開口（ASME B16.34中的位置“G”）檢查閥體空腔中的泄漏。如果操作考慮因素不允許閥門底部開口，則買方可指定另一個開口位置，并且閥門應(yīng)在試驗期間在閥門底部的位置進行雙重阻斷和排放試驗。所有位置的測試，特別是替代位置的測試將需要符合6.1.2要求的程序。測試持續(xù)時間不得少于表5.7閥門認證和重新測試7.1合格證書中規(guī)定值的兩倍（2×）。如果買方有規(guī)定，閥門制造商應(yīng)向買方提交采購訂單中要求的合格證書。
For valves designed to resist pressure closure in any direction (except double block and drain valves or globe valves), the pressure shall be applied to each side of the closed valve in turn, and the other side shall be opened to the atmosphere to check the leakage of the atmospheric side of the closing device. For globe valves, pressure shall be applied in one direction, under the disc. For valves designed to be closed and marked when subjected to pressure in only one direction, pressure shall be applied only on the pressure side of the valve. For check valves, pressure shall be applied on the downstream side. For butterfly valves equipped with sealing or elastic lining and designed for Class 125 or 150 flanges (API 609, Class A valves), the closure test shall be conducted in one direction only. For other flexible butterfly valves (API 609, Class B valve), the closing test shall be conducted in two directions. For butterfly valves with preferred flow direction, the closing test in the non preferred direction shall be based on the reduced differential pressure rating in that direction. 6.4.4 Trapping the test air or gas in the body cavity between the seats of the integral (solid or flexible) wedge gate valve, and then covering the valve seat with water or soap or similar solution does not constitute an acceptable low pressure closing test.
6.4.5 If the threaded connection in the valve body cavity allows the test procedure described in 6.6.1 for double block and drain valves, the connection shall comply with the requirements of MSS SP-45, and the solid pipe plug (in accordance with ASME B16.11) shall be installed before shipment, with the same material composition as the valve shell. 6.5 High pressure shutdown test The high pressure shutdown test procedure shall be the same as the low pressure shutdown test procedure, but if it is a liquid test, the leakage shall be detected when liquid drops are observed instead of bubbles described in 6.4. 6.6 Double block and discharge high-pressure closing test For double block and discharge valves, the pressure shall be successively applied to each side of the closing element through the valve port. Leakage in the valve body cavity shall be checked through the opening at the bottom of the valve (position "G" in ASME B16.34). If operational considerations do not permit an opening at the bottom of the valve, the purchaser may designate another opening location, and the valve shall be subjected to a double block and discharge test at the bottom of the valve during the test. Testing at all locations, especially at alternate locations, will require procedures that meet the requirements of 6.1.2. The test duration shall not be less than twice the value specified in Table 5.7 Valve Certification and Retesting 7.1 Certificate of Conformity (2 ×）。 If specified by the Purchaser, the valve manufacturer shall submit to the Purchaser the certificate of conformity required in the purchase order.
