Pump Installation
Foundation, baseplate, pipework and coupling alignment. Most pump problems that appear later start here.
Foundation and Baseplate
- Set the baseplate on a foundation that is flat, level and heavy enough to carry the set without flexing. Level the baseplate on shims close to the foundation bolts, not between them.
- Grout the baseplate before final alignment. Grout that has not cured will move, and any alignment done before it cures is lost.
- Check that the baseplate is level in both directions across the machined pads, not across the paint.
Suction Pipework
- Keep the suction line as short and as straight as the layout allows. Every bend close to the suction nozzle disturbs the flow into the impeller eye.
- Do not fit an elbow directly onto the suction flange. Allow a straight length of several pipe diameters ahead of the pump.
- On a suction lift, use an eccentric reducer with the flat side uppermost so no air pocket can form at the high point. On a flooded suction, the flat side goes underneath.
- The suction line should rise continuously towards the pump on a lift, with no high points where air can collect.
- Support the pipework independently. The pump nozzles are not there to carry the weight of the line.
Discharge Pipework
- Fit an isolating valve on the discharge so the pump can be started against a partly closed valve and isolated for service.
- Fit a non return valve between the pump and the isolating valve where the system can run backwards through the pump.
- Take the pressure gauge connection on a straight length, not immediately after a bend.
Coupling Alignment
- Align the coupling after the baseplate is grouted and after the pipework is connected and supported. Piping strain moves the pump.
- Check both parallel and angular alignment, and check it again once the pump has reached working temperature on hot duty.
- Refit the coupling guard before the set is energised.
Motor and Rotation
- Check the direction of rotation with the coupling element removed or the pump uncoupled. Running a centrifugal pump backwards can loosen the impeller.
- Confirm the arrow on the pump casing against the actual direction before coupling up.
Vertical Sump Pumps
- A wet installed vertical pump such as the VNP hangs from its cover plate into the pit. Check that the cover plate is level and properly supported before lowering the column.
- Set the immersion depth so the suction stays covered at the lowest working level in the pit.
- There is no suction line and no foot valve on a wet installation, so nothing needs priming.
Installation FAQ
Should I align the coupling before or after connecting the pipework
After. Connect and support the pipework first, then align, because piping strain pulls the pump out of line.
Which way round does an eccentric reducer go
Flat side uppermost on a suction lift so air cannot collect at the top. Flat side underneath on a flooded suction.
How much straight pipe do I need before the suction nozzle
Several pipe diameters of straight run. An elbow bolted directly to the suction flange gives an uneven flow into the impeller eye.
Do I need to grout the baseplate
Grout it and let it cure before final alignment. Alignment carried out on an ungrouted base does not hold.
How do I check the direction of rotation safely
Uncouple the pump or remove the coupling element, then bump the motor and compare the direction against the arrow on the casing.
Question About Installation
Send the pump series, the size and what you are seeing on site and we will come back to you.