MVME177PA-64SE工控备件模块
对于设计用于抵抗任何方向的压力关闭的阀门（双截断和排放阀或截止阀除外），应将压力依次施加到关闭阀门的每一侧，另一侧向大气开放，以检查关闭装置大气侧的泄漏情况。对于截止阀，应向一个方向施加压力，压力施加在阀盘下方。对于设计为仅在一个方向上承受压力时关闭并标记的阀门，应仅在阀门的压力侧施加压力。对于止回阀，应在下游侧施加压力。对于配有密封或弹性内衬且设计用于125级或150级法兰（API 609，A类阀门）的蝶阀，只需在一个方向上进行关闭试验。对于其他弹性蝶阀（API 609，B类阀门），需要在两个方向进行关闭试验。对于具有首选流动方向的蝶阀，非首选方向上的关闭试验应基于该方向上减小的压差额定值。6.4.4将试验空气或气体截留在一体式（实心或柔性）楔形闸阀阀座之间的体腔内，然后用水覆盖阀座或用肥皂或类似溶液覆盖阀座，不构成可接受的低压关闭试验。
6.4.5如果阀体空腔内的螺纹连接允许6.6.1中双截断和排放阀所述的测试程序，则该连接应符合MSS SP-45的要求，并应在装运前安装实心管塞（符合ASME B16.11），其材料成分与阀壳的材料成分相同。6.5高压关闭试验高压关闭试验程序应与低压关闭试验程序相同，但如果是液体试验，则应在观察到液滴而非6.4中所述的气泡时检测泄漏。6.6双阻断和排放高压关闭试验对于双阻断和泄放阀，应通过阀门端口将压力依次施加到关闭件的每一侧。应通过阀门底部的开口（ASME B16.34中的位置“G”）检查阀体空腔中的泄漏。如果操作考虑因素不允许阀门底部开口，则买方可指定另一个开口位置，并且阀门应在试验期间在阀门底部的位置进行双重阻断和排放试验。所有位置的测试，特别是替代位置的测试将需要符合6.1.2要求的程序。测试持续时间不得少于表5.7阀门认证和重新测试7.1合格证书中规定值的两倍（2×）。如果买方有规定，阀门制造商应向买方提交采购订单中要求的合格证书。
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.
