Flowserve FPS 14 - Manual (Page 8)

6. Check the operation of the Vent and Pressure valves.
CAUTION: At the end of each pumping cycle, when the vent valve first opens, there will be a
puff of motive gas (Steam, air, or gas) as the tank is depressurizing. This is normal and should
not be mistaken for a leaking pressure valve. Be careful when troubleshooting, and only put
your hand near the vent after the initial puff disappears.
a.) Close the isolation valve on the vent line. If a ball valve has been installed on a tee in the
vent line, open the valve. If not, detach the vent line so that it is open to atmosphere.
b.) When the pump is in the filling cycle, the vent valve should be open and there should be a
flow of gas from the vent. This is the pump contents being evacuated as the liquid fills the
pump tank. If there is no flow of gas from the vent then the vent valve either has not
opened or has a blockage. The mechanism will have to be removed from the tank and
inspected to resolve this problem. See MAINTENANCE Instructions.
c.) If the full motive gas pressure is found at the vent, this indicated either that the pressure
valve is not closed, or that there is a leak in the pressure valve. If this is the case, close and
re-open the isolation valve on the pressure supply line. This may dislodge any debris. If
there is still full motive gas pressure at the vent or the pump still will not fill properly, the
mechanism must be removed from the tank and inspected. See MAINTENANCE
Instructions.
d.) Closed System: If the pump begins to fill when the vent valve is open to atmosphere and
stops when the vent line is reconnected to the return tank, then the pump is vapor locked.
A thermostatic air vent must be installed on the vent line at the highest point, and the vent
line must be self-draining.
PROBLEM – Pump will not properly discharge the condensate after filling
1. Are all of the isolation valves open?
Check the isolation valves on the pump outlet and motive supply line. If these are closed, open
the valves and check for proper pump operation. Check all strainer screens for obstruction.
Clean the strainers if necessary and check for proper pump operation.
2. Is there motive gas pressure (steam, air, or gas) to the pump?
Verify that all pressure supply valves are open, and that there is pressure at the motive gas
supply inlet.
If there is no motive gas pressure, check the motive gas supply system and pressure valve for
clogging.
3. Is the motive gas pressure (steam, air, or gas) high enough for proper operation?
The motive gas pressure must be high enough to overcome the backpressure after the pump
and high enough to provide the required pumping capacity. If there is not a pressure gauge
installed on the outlet of the pump, the backpressure can be measured during the pumping
cycle by installing a pressure gauge in the ¼” NPT connection on the top of the cover flange.
The pressure in the tank during the pumping cycle is approximately 2 – 3 psig higher than the
backpressure. If the pump tank pressure equals the motive gas pressure, the motive gas
pressure is not high enough to overcome the backpressure on the pump.
If the motive gas pressure is not high enough to overcome the backpressure then increase the
motive gas pressure.