4.1.6 Optimising flow conditions
1. Avoid bending radii that are smaller than 1.5
times the nominal pipe diameter.
2. Avoid abrupt changes of cross-section and
direction along the pipes.
4.1.7 Handling leaks
1. Provide equipment for collecting and discharging
leaking liquids.
2. Make sure that leaking liquids can be freely
discharged.
4.1.8 Avoiding excessive pressure
1. Observe the operating instructions of the
manufacturer.
2. Make sure the settings of the pressure relief
valve meet the requirements of the system.
3. Do not feed the return flow from the safety valve
directly back into the inlet pipe.
4.1.9 Further safety and control equipment
(recommended)
•
Install a dirt trap in the inlet pipe (mesh size: 0.6
mm).
•
Provide a fine filter, if necessary. See section
7.1 Operating
conditions.
•
Install a non-return valve between the outlet
flange and the isolating valve to ensure that liquid
does not flow back when the pump is stopped.
•
Install isolating valves in the inlet and outlet pipes
to facilitate maintenance and repair work.
•
Provide pressure gauges for pressure
measurements in the inlet and outlet pipes.
•
Provide inlet-side temperature measurements.
Only necessary for hot or hazardous pumped liquids:
•
Provide leak monitoring equipment.
Collect any leaking pumped liquid and dispose of it in
accordance with local environmental rules and
requirements.
4.1.10 Connecting the pipes
Remove any impurities in the pump before
connecting the pipes in order to avoid
material damage.
Keeping the pipes clean
1. Flush all pipe parts and fittings before
connection.
2. Make sure that no flange seals protrude inwards.
3. Remove any blank flanges, plugs, protective foils
and/or protective paint from the flanges.
4. Remove any welding beads from welded pipes.
Connecting the inlet pipe, if any
1. Remove the transport screw plugs from the
pump.
– run the pipes with a continuous downward
slope towards the pump to avoid air pockets.
2. Make sure that no seals protrude inwards.
3. For tank-top and in-tank installations: Observe
the minimum immersion depth. See section
4.1.11 Liquid
level.
Connecting the outlet pipe
1. Remove the transport screw plugs from the
pump.
2. Connect the outlet pipe.
3. Make sure that no seals protrude inwards.
Checking pipe connections for stress
1. Before checking, make sure that the pipes are
connected and cooled down.
2. Disconnect the pipe flanges from the pump.
3. Ensure that the pipes can be moved freely in all
directions within the expected range of
expansion:
– nominal diameter < 150 mm: By hand
– nominal diameter > 150 mm: With a small
lever.
4. Make sure that flange surfaces are parallel.
5. Reconnect the pipe flanges to the pump.
11