调节阀泄漏量测试标准.docVIP

4 LEAKAGE SPECIFICAITONS AND CLASSES 泄漏等级和相关规定 4.1The maximum allowable seat leakage as specified for each class shall not exceed the set leakage in Table 1 using the test procedure as defined in Section 5. For Classes II through VI , each and every valve shall be tested . 在表1中给出不同的泄漏等级的最大泄漏量，并按第五部分所要求的测试程序去测试。 要达到等级2到等级6中的任一等级，每一个阀都必须测试。 4.2 Leakage Classes 泄漏等级 4.2.1 Class I . A modification of any Class II ,III or IV valve where design intent is the same as the basic class , but by agreement between user and supplier , no test is required . 一级密封 是根据等级二，三，四 来设计制造的，但是供方和用户已达成协议不需要测试。 4.2.2 Class II . This class establishes the maximum permissible leakage generally associated with commercial double port , double seat control valves or balanced single port control valves with a piston ring seal and metal to metal seats . Use test procedure Type A. 二级密封 主要是针对 工业双通双座控制阀或平衡型单通控制阀 那些带有活塞O型圈密封和金属对金属阀座密封。 使用A 类测试程序。 4.2.3 Class III This class establishes the maximum permissible leakage generally associated with Class II (4.2.2) , but a higher degree of seat and seal tightness . Use test procedure Type A. 三级密封 主要是针对那些阀座和密封硬度更高的二级密封所规定的相关的阀。规定了最大允许的最大泄漏量。使用A 类测试程序。 4.2.4 Class IV This class establishes the maximum permissible leakage generally associated with commercial unbalanced single-port , single-seat control valves and balanced single-port control valves with extra tight piston rings or other sealing means and metal to metal seats. Use test procedure Type A . 四级密封 主要是针对工业非平衡单孔单座控制阀和平衡型单孔控制阀带有紧固型活塞式密封圈或其他密封形式和金属密封，规定了最大允许泄漏量。使用A 类测试程序。 4.2.5 Class V This class is usually specified for critical applications where the control valve may be required to be closed , without a blocking valve , for long period of time with high differential pressure across the seating surfaces . It requires special manufacturing assembly and testing techniques . This class is generally associated with metal seat unbalanced single-port , single seat control valves or balanced singl