Flowserve FPS 14 - Manual (Page 10)

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 – Chattering or Banging in condensate return line after pump has discharged
1. Are the multiple rises and drops after the pump discharge?
If so, install a vacuum breaker on the highest point in the return line. For a closed system install
an air vent downstream of the vacuum breaker.
2. Does the condensate inlet pressure to the pump exceed the condensate return line pressure?
If so, this indicates the probability that live steam is blowing through the pump.