12
Vacuum Sentry
TM
safety Valve
Troubleshooting
This section is a guide for solving problems that may occur with the HPS
TM
Vacuum Sentry
TM
Valve. Listed below are symptoms with possible causes
and suggestions for help.
Valve Cannot Be Pumped Down to High Vacuum
1.
Valve leaks from external atmosphere into vacuum system.
First check that the solenoid has proper electrical power
applied to the coil. If the solenoid appears to be functional,
then carefully leak test with a quality leak detector.
With careless leak detection, a leak a large distance away can
be picked up and the leaking component not found. Some
possible sources of leaks are:
a.
Non-sealing flanges between valve and system
may be due to damaged flanges, damaged O-ring,
dirt, loose clamps, or incorrect assembly. Locate
the problem and assemble correctly.
b.
If a leak signal is obtained at the solenoid / bonnet
connection, disassemble, clean, and reassemble.
c.
A leak signal at the solenoid intake indicates a
defective solenoid valve. Disassembly of the
solenoid valve is not recommended. Install a new
solenoid valve.
If the solenoid valve is replaced by a unit not supplied by
HPS
TM
, it is the responsibility of the user to insure that it is
sufficiently leak tight to meet the specifications.
d.
Leaks are found between the body and the bolted
flanges or bonnet. Isolate the offending seal
interface and disassemble. Inspect for damage or
dirt at the seal surfaces. Clean and reassemble as
described above.
2.
Valve is dirty and contaminated with a material that is
outgassing or blocking the orifices. Correct by thoroughly
cleaning the valve.
