3788350 is referenced by 3 patents and cites 7 patents.

A valve assembly is described of the so-called block and vent type wherein the valve is normally closed with the downstream side vented. When a pilot pressure is applied, it first closes the vent and then opens the valve partially. On application of a second pilot signal from another source or from a suitable time delay network, the valve opens fully. On release of the pilot pressures, the valve closes first and then opens the downstream vent.

Title
Block and vent valve
Application Number
05/349,457
Publication Number
3788350
Application Date
April 9, 1973
Publication Date
January 29, 1974
Inventor
West Benjamin W
Agent
Fitch Even Fabin & Luedeka
Assignee
California Controls Company
IPC
F15b 13/42
F15b 11/08
F16K 31/122
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