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MOTOR DRIVEN PUMPS - INSTALLATION AND OPERATION
7) Connect and set the pressure switch to a set-point
approx. 10-30 psi above the system process
pressure. Ensure the switch is set at a pressure
between the Nitrogen set point and the max
anticipated discharge pressure. This pressure
switch should be wired to a panel or warning light or
alarm to prevent a decrease in barrier fluid pressure
below the pressure of the process fluid. This would
prevent process fluid from ever escaping into the
intra-seal cavity and potentially to atmosphere.
Dual Seal designs require sensing
devices to monitor seal performance
and detect leakage. Failure to properly
install sensing devices may result in
product leakage.
Hazardous or toxic
fluids can cause
serious injury.
8) A sensing device is required to ensure that
process fluid does not escape pump in case of
seal failure. If the seal fails, the barrier fluid
pressure and the barrier fluid level in the SPA
will drop. A pressure switch or a liquid level
switch may be used to sense these conditions
and the system should then be shut down to
prevent product leakage to atmosphere.
9) For the Plan 52 Seal only: Ensure the SPA tank is
vented to atmosphere through an orifice. The vapor
space of the Seal Pot should be open atmospheric
pressure during operation. The tank should be kept
below discharge pressure of the pump, at all times.
This includes during periods of non-operation. If the
SPA tank pressure exceeds discharge pressure, the
outer seal can open and may cause contamination of
barrier oil into system. The seal may not reseat
once pressure is dropped.
10) Close the SPA tank vent and slowly allow the pump
to fill with the pumping fluid while monitoring the SPA
tank pressure and barrier oil level (if possible). If the
barrier oil pressure or level increases, there is a seal
leak and the pump should be removed from service
and replaced.
11) Connect and set a pressure switch to a set-point of
approx. 10 psig. This pressure switch should be
wired to a panel or warning light or alarm to prevent
the barrier pressure from exceeding the process
pressure. This would prevent barrier fluid leaking into
the system or process fluid from contaminating the
barrier oil due to the outer seal opening.
Note: A suitable orifice should be installed inline.
This will allow a leak to be detected by
increasing the SPA tank pressure. Under normal
operation vapor emissions should be properly
contained and disposed (e.g. flared off).
Figure 7 Plan 52 Pressure Switch Installation
Dual Seal designs require sensing
devices to monitor seal performance
and detect leakage. Failure to properly
install sensing devices may result in
product leakage.
Hazardous or toxic
fluids can cause
serious injury.
12) A sensing device is required to ensure that
process fluid does not escape pump in case of
seal failure. If the seal fails, the barrier fluid
pressure and the barrier fluid level in the SPA
will increase. A pressure switch or a liquid level
switch must be used to sense these conditions
and the system should then be shut down to
prevent product leakage to atmosphere.
INSTALLATION AND CONNECTION:
13) The following is a checklist for completion prior to
operation of the pump:
All plumbing connected, 1 barrier fluid supply line
to each side of pump and one return line to each
side of pump.
All air has been bled out of system.
Bleed valve shut. Seal supply and Seal return
valves open.
Pressure of barrier fluid system is 30 – 50 psi
above process pressure for the Plan 53 Seal or at 0
psig for the Plan 52 Seal.
Once pressurized, the nitrogen pressure supply to
the SPA is shut off for the Plan 53.
SPA pressure is constant.
There are no barrier fluid leaks in the
tubing/piping/hoses.
Open pump inlet valve and ensure no process
fluid leakage.
Open pump discharge valve
During operation, pressure in the barrier fluid
system (SPA) stays constant.
Having completed these steps and the checklist above, the
pump should be ready for operation.
