Domestic Water Pump - Gentle/Soft/Slow Start Needed: Can I do this with a capacitor?

Question

When my new 3.5 bar water pump starts up, it makes a shocking clonking noise. It is well anchored but I'm afraid of medium/long term damage to both pump and pipework.

What is the correct way to get this pump to start up gently? I am looking for a simple solution that I can make at home with a soldering iron and the right component(s). If you can help me solve this, it's at least a bottle of champage for you (if you're in the UK -- otherwise something equally rewarding but easier to ship!).

fyi, the pump uses single-phase AC and is rated at under a kW.


TIA and all that good stuff if you can help.

Biffo

Answer 1

If there is a straight run of pipe either side of the pump, I would suggest adding a loop of pipe either side (not a complete circle, just an up, along, down, along) _[~]_ to give a degree of flexibility in the pipework. You cannot soft start an AC motor with a capacitor. Another thing you might try is a gate valve to partially restrict the output. Is it the right size pump for the job?

Hope this helps.