Installation
TT Twin-Screw Pump -
Installation, Operation & Maintenance Manual
43
Discharge piping checklist
Checklist
Check
Explanation/comment
Checked
Check that an isolation valve is
installed in the discharge line
The isolation valve is required for inspection and
maintenance of the pump
Check that a check valve is installed in
the discharge line, between the
isolation valve and the pump
discharge outlet.
The location between the isolation valve and the
pump allows inspection of the check valve.
The check valve will prevent hydraulic shock acting
upon the pump and will also prevent reverse rotation
of the pump when stopping the unit.
Check that a vent valve is installed in
the discharge piping prior to the check
valve.
This is only mandatory if pump operates with a
suction lift.
Fit suitable pressure relief valve to the
pump discharge
Pressure relief valves must be installed between the
discharge valve and the casing discharge flange of
2-Screw pumps to protect both the pump and piping
system. The valve and piping system must be
solidly constructed of proper material with ample
opening for passage of full discharge capacity,
because positive displacement pumps can build up
pressure rapidly, if the discharge is restricted or shut
off. This type of relief valve must lead back to the
source of supply or other suitable collecting point to
prevent product loss and an excessive temperature
rise of the re-circulated fluid in pump that operate
unattended.
Auxiliary-piping checklist
Precautions
CAUTION:
Risk of significant heat generation, seal failure, and possible physical injury. Sealing systems
that are not self-purging or self-venting require manual venting prior to operation. Read the
seal system supplier’s instructions to confirm venting requirements.
Running a mechanical seal dry, even momentarily, can cause seal failure and physical injury.
Never operate the pump without confirming that liquid is supplied to the mechanical seal.
Auxiliary cooling and flush systems must be operating properly to prevent excess heat
generation, sparks, and/or premature failure.
NOTICE:
Ensure auxiliary piping is installed as specified on the pump data sheet prior to startup.
