| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a check valve capable of remarkably reducing a pressure loss in comparison with a conventional check valve. <P>SOLUTION: This check valve includes a casing 2 having a valve seat 10 formed in a flow path and a valve element assembly 21 arranged in the casing 2. A top 23 of a valve element 22 is received in a large-diameter portion 38 of a through-hole 37 in a support member 35 of the valve element assembly. A narrow flow path portion 68 (a first portion of an intermediate flow path), which is formed between an arcuate portion 46 of an outer periphery 45 of the support member and a second enlarged-diameter portion 12 of the casing and which has a small flow passage area, is communicated with a back pressure chamber 50 defined in the support member at the rear of the top of the valve element through a communicating passage 67 including a gap 66 between the outer periphery of the valve element and the inner periphery of the large-diameter part and a groove part 27 on the rear surface of the top of the valve element. A low static pressure of water flowing through the narrow flow path is introduced into the back-pressure chamber. Water passing through the narrow flow pathe portion enters a diffuser flow path portion 69 as a second part of the intermediate flow passage, and recovers the static pressure while flowing therethrough. Next, the water flows downstream through a uniform flow path as a third portion of the intermediate flow path while maintaining the recovered static pressure. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
