| 摘要 |
<p>A combination pressure reducer and flow control valve which include a valve body and cover means having an upstream port and a downstream port, and two parallel fluid flow passages interconnecting said ports. An adjustable differential pressure valve means is operatively mounted in a first one of said two parallel fluid flow passages for reducing the upstream pressure of fluid entering the upstream port to provide a reduced downstream pressure at the downstream pressure port. A check valve means is operatively mounted in the second one of said two parallel fluid flow passages and it is operative to check the flow of fluid through said second one of said two parallel fluid flow passages when fluid is flowing through said first one of said two parallel fluid flow passages, and to allow flow of fluid through said second one of said two parallel fluid flow passages when fluid is exhausted into said downstream port and out the upstream pressure port. An adjustable fluid flow control valve means is operatively mounted in either one of said two parallel fluid flow passages to provide either a meter in or a meter out action to the flow of fluid through the passage in which the adjustable fluid flow control valve means is mounted. The function of the check valve means and the adjustable fluid flow control valve means may be incorporated in a single valve means for a meter out action. An adjustable pre-exhaust valve means may be included for quickly exhausting downstream pressure simultaneously with the exhaust of fluid flow through the check valve means.</p> |
