The slide valve includes a pre loaded spring, capable in {TAIL ~ the absence} of {HEAD ~ other force} of moving the slide valve to its closed position to lock the member against movement 
The slide valve includes a pre loaded spring , capable in { TAIL ~ the absence } of { HEAD ~ other force } of moving the slide valve to its closed position to lock the member against movement
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH