Vacuum Sentry
TM
safety Valve
13
Valve Leaks in Closed Position
1.
Check for proper installation. The valve has been designed
to vent the roughing pump upon closure. If the valve has
inadvertently been installed backwards it would isolate the
pump and vent the system. Reinstall the valve correctly
with the flow arrow on the body label pointing toward the
mechanical vacuum pump.
2.
Nosepiece O-ring leaks. Confirm leak using a leak detector.
Replace O-ring as described previously.
3.
O-ring (15) leaks. Check for loose screws. Confirm leak
using a leak detector. Replace O-ring as
described previously.
Valve Closes Too Slowly
1.
Inlet filter to solenoid valve is clogged. Clean or
replace filter.
2.
Solenoid valve is defective. Replace with a new
solenoid valve.
3.
There is excess friction between bushing (2) and guide pin
(1). Clean and repair the bushing and guide pin as
described above.
4.
The spring is restricted by contamination. Disassemble,
clean, or replace.
Valve Opens Too Slowly or Not Completely
1.
The orifices are partially blocked. Clean and reassemble.
2.
There is excess friction between bushing (2) and guide pin
(1). Clean and repair the bushing and guide pin as
described above.
3.
The diaphragm or spring is contaminated. Disassemble,
clean or replace, and reassemble.
Valve Fails to Open
1.
The solenoid valve has a leak or will not close properly
preventing the evacuation of the chamber over the piston
(4). Check to make sure that electrical power has been
restored to the solenoid valve. If the solenoid valve is
energized then leak check to confirm leak and replace
solenoid, if unit is found to be defective.
