Appendix A
Check Valve Operation
A-2
Locking Down Check Valve for Line Testing
Turning the service screw all the way clockwise, seals the relief valve and at the same time locks down and seals
the check valve as shown in Figure A-3. The line is now isolated for pressure testing.
Figure A-3. Locking down the check valve for line testing
Removing Check Valve
When removal of the check valve is desired, turn the service screw clockwise until it is all the way down as shown
in Figure A-4. At about 7.5 clockwise turns, the relief valve will open (you will hear line pressure vent) and the
service screw will lock onto the check valve. When you have turned the service screw all the way down, back off 3
or 4 turns (counterclockwise) and wait a few seconds for the product in the manifold to drain out. Unscrew the
check valve housing and remove the complete valve assembly.
Figure A-4. Removal of check valve assembly for service
rjpumps\ckvlv4
Service screw full down
seals off check valve
and relief valve to
isolate line from tank
Service screw
To tank
To line
rjpumps\ckvlv5
To tank
Product drains
from line
Check valve supported
by snap ring
