Bell & Gossett P81568D Series 1535 - Manual (Page 13)

Piping checklist
WARNING:
• The heating of water and other fluids causes volumetric expansion. The associated forces
can cause the failure of system components and the release of high-temperature fluids.
In order to prevent this, install properly sized and located compression tanks and
pressure-relief valves. Failure to follow these instructions can result in serious personal
injury or death, or property damage.
• Avoid serious personal injury and property damage. Make sure that the flange bolts are
adequately torqued.
• Never force piping to make a connection with a pump.
Check Explanation/comment Checked
Check that a section of straight pipe, with a length that
is five times its diameter, is installed between the
suction side of the pump and the first elbow, or that a
suction diffuser is installed.
This reduces suction turbulence by
straightening the flow of liquid before it enters
the pump.
Check that the suction and discharge pipes are
supported independently by use of pipe hangers near
the pump .
This eliminates pipe strain on the pump .
Check that there is a strong, rigid support for the
suction and discharge lines.
As a rule, ordinary wire or band hangers are not
adequate to maintain proper alignment.
For pumps with flanges, check that the bolt holes in
the pump flanges match the bolt holes in the pipe
flanges.
—
Check that the suction or discharge lines are not
forced into position.
Coupling and bearing wear will result if suction
or discharge lines are forced into position.
Check that fittings for absorbing expansion are
installed in the system when considerable
temperature changes are expected.
This helps to avoid strain on the pump.
Check that flexible piping is used on both the suction
and discharge sides of the pump when you use an
isolation base.
—
Check that a triple duty valve is installed in the
discharge line.
This valve serves as a check valve that protects
the pump from water hammer, and serves as
an isolation valve for servicing and for
throttling.
Check that the pipeline has isolation valves around
the pump and has a drain valve in the suction pipe.
—
Use PTFE tape sealer or a high quality thread sealant
when you install the suction and discharge
connections to a threaded pump housing.
—
On an open system, check that the end of the suction
pipe is at least 3 ft. below the surface of the water in
the suction well.
Where there is suction lift, make sure that horizontal
runs of the suction pipe slope down from the pump
toward the suction well and never slope up.
This prevents air from being drawn into the
pump. Avoid air pockets in the suction line and
make sure that each section of the suction pipe
is air tight.
Installation
12 Series 1535 Installation, Operation, and Maintenance Manual