Stuart Turner water pump

[Nev]

Some advice, you have not let me down to date!

 

My boat has a Stuart Turner water pump with a separate Pumptrol pressure switch and a failed accumulator tank. We are having some work done on the kitchen so I have stripped back the plumbing and will need to reinstall it. The Pumptrol pressure switch is very 'rusty' so I expect it has a small lek somewhere within it, not one I can identify. (The boat has a gas water heater (if that should be an issue when selecting water pumps)

 

Now when the boat was surveyed the surveyor was impressed with the Stuart Turner pump. I am nor sure what to replace when I put the plumbing back together, should I opt for a more modern pump with built in pressure switch or do I replace the Pumptrol pressure switch and stick with the Stuart Turner?

 

Is this pump ok for a freshwater system - I intend replacing the old water filter anyhow ?

 

Also I presume it is best to replace the failed accumulator tank to keep the cycling down on the pump?

 

 

Any advice would be appreciated,

 

Kind regards

 

Nev NB Percy

 

 

[Tony Brooks]

This is from memory. I think most ST pumps were centrifugal pumps rather than diaphragm or flexible impeller pumps. and are fine in any sort of water. The pump head itself has no wearing parts apart from a seal and possibly a bearing but I think its the motor bearing that supports the impeller. There are two problems.

 

1. The impeller may be capable of blocking with debris so it is worth taking the pump cover off and inspecting it. I think the impeller consists of two plates with the flutes between them. It the gap between the plates that block. A strainer on the inlet should prevent problems.

 

2. Being centrifugal it will not pump air like modern pumps can so if you drain or run the tank dry it can be interesting getting the pump to bleed. However I have always found a full tank and a good suck on a single open tap sorts it.

 

If it is a centrifugal pump there must also be a non-return valve on the inlet.

 

Any adjustable pressure switch will do. You can still get the D Square ones on Ebay otherwise use a caravan (Whale) pressure switch driving an automotive relay.

 

An accumulator is always nice to have.

 

The question of using or replacing the ST pump I think comes down to the availability of spares and the ease/cost of repair and I think that all of these would suggest that a modern pump may be a better bet in the longer term but if immediate cost is a problem then stick with the pump you have.

[The Bagdad Boatman (waits)]

The accumulator is like a football bladder which can be reinflated with a car tyre pump. some loose pressure over time.

[Tony Brooks]

To add.

 

I think those pumps use wound field coils so they will use more current than a modern pump but in water pump duty I doubt it would be significant on most boats.

[Timleech]

To add.

 

I think those pumps use wound field coils so they will use more current than a modern pump but in water pump duty I doubt it would be significant on most boats.

 

They do, but they sound better than a diaphragm pump

 

Tim

[Nev]

Gentlemen,

 

Many thanks for taking the time to reply to my request for advice, I really do appreciate it. Especially Tony for such a complete reply.

 

I agree with Tim on the sound comment the modern diaphragm pumps do not make a good noise !

 

A follow up question - I note the comment about current draw, but this pump does not seems to need to run for much time to pressure the system. I know this will depend on the boat plumbing, but in general would a centrifugal pump move more water?

 

I think I'll take a close look at the pump, give it a good clean and some lubrication and then investigate a replacement switch. I like to keep the old if possible.

 

I'll also see if the accumulator will take some pressure, I foolishly assumed it was failed but as the Bagdad Boatman advised the bladder may just be completely deflated.

 

Thanks again for your help and support,

 

Nev

[Tony Brooks]

I suspect it would move more water but as the pressure increases it will tend to move less and less.

 

It is because domestic water pumps run for such short periods that I said any extra current draw would not be significant. However if you were trying to run your domestics on a 35Ah car battery then it would be.

[Robbo]

This is from memory. I think most ST pumps were centrifugal pumps rather than diaphragm or flexible impeller pumps. and are fine in any sort of water. The pump head itself has no wearing parts apart from a seal and possibly a bearing but I think its the motor bearing that supports the impeller. There are two problems.

 

If its a centrifugal pump it won't need an accumulator.