pump distance from tank

[Nozzle]

according to the manufacturer guide the run from the tank to the pump cannot exceed 4m of 22mm. they don't say why.

I would suggest it is to do with net positive suction head. The higher the expected flow of the pump, the more the pressure will drop at the eye of the pump.

Statically, the pressure at the eye of the pump depends only on the heigh of your head tank. But if you put 1000 yard of pipes between the head tank and the suction of the pump, as soon as the water starts to move the dynamic pressure drop increases. If it increases over and above the static pressure then the pump will cavitate and will sound like there's gravel rumbling around in there.

Nozzle

 

[motorbiking]

I dont understand what your problem is.

You seemed to be saying the pump cannot go by cylinder. I thought that was because it will not fit.

Now you are saying that it can fit there.

So what is your problem about fitting it there with a short supply pipe length?

Tony

originally it was all agreed that the pump would go in the airing cupboard. Then plumber told Mrs it can't because of the pipes in the loft and would have to go in bathroom instead. further she was told it would be better that way. so she agreed. All this without the knowledge that 1. it probably could have gone in the airing cupboard had they been willing to sort the loft pipe work out and 2. it's not better in the bathroom as no bugger makes decent pumps that can go that far away from the cylinder.

and now the pipe work has been installed for the pump to be in the bathroom and the finishing trades have completed their work.

so my dilemma is find a pump that will work. e.g a regenerative pump which Stuart turner don't make. or insist on a better quality pump where the risk is reduced.

does that make sense?

 

[Agile]

Noz has explained why the pump needs to be close to the water supply tank or to have large diameter pipework with low resistance.

It is not the pump design which is involved. It is the flow resistance of the pipework!

So it seems the problem has been caused by the builder's useless plumber!

An aggressive person would blame the employing builder and require them to site the pump by the cylinder and make good any tiling in the bathroom.

I am glad that I can do my own plumbing and don't have to reply on builders!

Tony

 

[dilalio]

I am glad that I can do my own plumbing and don't have to reply on builders!

Tony, I couldn't agree more! Plumbing for builders is a fookin nightmare... They want you at the drop of a hat, think they can pay you peanuts but want more than you'd ask out of their client, and send you on fools errands all over the place... And expect you to do your work with all the other trades coming at you from every angle