Normally closed pneumatic diaphragm valve with mechanical override with lockout

Abstract

A pneumatic valve with lockout for controlling the flow of a fluid includes a housing, a fluid flow passage extending through the housing between a fluid inlet and a fluid outlet, and a valve movable along an axis to open and close the flow passage. A pneumatic actuator is operable to move the valve to open and close the flow passage. A manual lockout device is actuable to selectively enable and actuation of disable the valve. The device includes a locking member movable to prevent the lockout device when the valve is disabled. A fitting on the housing to convey a pressurized gas to the pneumatic actuator is mounted to swivel about the housing for connection to an air source on any radial within 360°. The valve is compact, simple to connect in a system and safe.

1 . A normally closed pneumatic diaphragm valve with mechanical override with lockout for controlling the flow of a fluid, comprising:
 a housing which is elongated along an axis of the valve, the housing having a surface mount body at one axial end of the housing which defines a footprint of the valve when mounted on an apparatus;   a fluid flow passage extending through the housing between a fluid inlet and a fluid outlet in the surface mount body;   a diaphragm valve movable along said axis to open and close the flow passage;   a pneumatic actuator located at an opposite end of said housing from said one end and operable to move the diaphragm valve to open and close the flow passage;   a manual lockout device located adjacent said opposite end of the housing and within said footprint of the valve, the lockout device being rotatable around said axis relative to the housing between a position to enable the valve to be opened by the pneumatic actuator and a position to disable the valve in a position closing the flow passage, the device including a locking member selectively movable to a position preventing rotation of the lockout device from the disabled position.   
   
   
       2 . The pneumatic valve with lockout according to  claim 1 , wherein the manual lockout device includes a knob rotatable relative to said housing between said position to enable the valve and said position to disable the valve, and wherein said locking member is mounted in said knob and selectively movable to and from the housing when the knob is in the disabled position to respectively prevent and permit rotation of the knob relative to said housing. 
   
   
       3 . The pneumatic valve with lockout according to  claim 2 , wherein said housing includes an aperture in which an end of said locking member is received to prevent rotation of the knob relative to the housing when the locking member is moved to the housing with the knob in the disabled position. 
   
   
       4 . The pneumatic valve with lockout according to  claim 2 , wherein said knob further includes a hole for a locking device selected from the group consisting of a padlock and a cable, movement of said locking member to the housing exposing said hole to allow the locking device to be inserted through the hole to preclude movement of the locking member from the housing. 
   
   
       5 . The pneumatic valve with lockout according to  claim 2 , further comprising a pair of control pins protruding from the locking member in opposite directions through openings in the knob for manual movement of the locking member. 
   
   
       6 . The pneumatic valve with lockout according to  claim 2 , wherein the manual lockout device further comprises a spring yieldably biasing said locking member for movement from said housing. 
   
   
       7 . The pneumatic valve with lockout according to  claim 2 , wherein the manual lockout device further includes a stem having one end affixed to said knob for rotation therewith and a second, threaded end rotatably engaged in a threaded hole in said actuator for translation to enable and disable the valve. 
   
   
       8 . The pneumatic valve with lockout according to  claim 1 , wherein said diaphragm valve includes a flexible diaphragm movable with respect to a valve seat about the flow passage to open and close the flow passage. 
   
   
       9 . The pneumatic valve with lockout according to  claim 1 , including a fitting to convey a pressurized gas to and from the pneumatic actuator for respectively pressurizing and venting the actuator.