PRESSURE WATER SYSTEM QUESTION PLEASE

Robin

Robin

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Our ancient freshwater pressure pump gave up theghost yesterday and we now have a more powerful one working fine but the higher pressure makes the taps throb especially at low flow rates. The original system has no accumulator/expansion tanks and I'm wondering if we should now add one.

Question What is the difference between an 'accumulator' tank and an 'expansion' tank? is their location in the system the only difference as Surecal list both and visually they seem identical?.... suggested size being 2 litres for our Surecal 30l calorifier and new 115 psi (Whale) pump.

TIA for usual informed responses!
 
afaik they are the same thing and yes, you need one to smooth out the flow of water. They also prevent the pump running the instant you crack a tap - often you only need a splash or a little more and the expansion tank takes care of maintaining the pressure to allow that without running the pump immediately. This saves wear on the pump and provides a smoother waterflow.
Use the data provided by manufacturers to decide the size of the expansion tank.
Well worth the effort to civilise your water delivery.
 
Robin said:
Our ancient freshwater pressure pump gave up theghost yesterday and we now have a more powerful one working fine but the higher pressure makes the taps throb especially at low flow rates. The original system has no accumulator/expansion tanks and I'm wondering if we should now add one.

Question What is the difference between an 'accumulator' tank and an 'expansion' tank? is their location in the system the only difference as Surecal list both and visually they seem identical?.... suggested size being 2 litres for our Surecal 30l calorifier and new 115 psi (Whale) pump.

TIA for usual informed responses!
Click to expand...

Thee accumulator tank is to smooth out the water flow by accumulating pressure, a 2ltr one seems about right for you, it is fitted in the cold pipe, after the pump. The expansion tank is there to prevent expansion of the hot water system damaging the calorifier and/or hot water pipes etc, it is located somewhere after the calorifier, in the hot water pipes. The Surcal sit is good for digrams. The two tanks are the saem, but have different pressures, again, the Surecal website gives useful info. Your Surecal calorifier should have a 5ltr expansion tank. It's important to fit the expansion tank, as the Surecal calorifier has a no-return valve in the cold water supply to the calorifier, which means there is no room for expansion without the tank. The Surcal warranty is also void without the expansion tank.
 
Some pumps are designed to work without an expansion tank as they have a bypass. Is the replacement one of those? Even with one of those they can pulse if you only turn the tap on a little bit. I guess a larger pump could show this more readily as you would be using less of its capacity at the same tap position.
 
PaulRainbow said:
Thee accumulator tank is to smooth out the water flow by accumulating pressure, a 2ltr one seems about right for you, it is fitted in the cold pipe, after the pump. The expansion tank is there to prevent expansion of the hot water system damaging the calorifier and/or hot water pipes etc, it is located somewhere after the calorifier, in the hot water pipes. The Surcal sit is good for digrams. The two tanks are the saem, but have different pressures, again, the Surecal website gives useful info. Your Surecal calorifier should have a 5ltr expansion tank. It's important to fit the expansion tank, as the Surecal calorifier has a no-return valve in the cold water supply to the calorifier, which means there is no room for expansion without the tank. The Surcal warranty is also void without the expansion tank.
Click to expand...

They (Richardsons, our on site engineers) fitted a new Whale 18L UNIVERSAL pump as the original Flojet one, probably 25 years old and deemed irreparable was leaking internally hence the irritating running every 5 secs or so. Not sure where I read the pressure as 115psi as I was trying to look on line for how much it was going to cost, might have been Amazon and a typo or misread. looking on Whale website now it seems pressure is 'up to 45 psi.
 
Our fairly old pump gave up a year or two ago. It had been fitted without a filter, but this is worth adding if you haven’t already got one. If possible, fit the accumulator tank somewhere accessible since you may need access to it from time to time to re-pressurise it.
 
johnalison said:
Our fairly old pump gave up a year or two ago. It had been fitted without a filter, but this is worth adding if you haven’t already got one. If possible, fit the accumulator tank somewhere accessible since you may need access to it from time to time to re-pressurise it.
Click to expand...

The new pump came fitted with a filter as supplied. If an accumulator is installed it would be in the same place as the pump, accessible but not instantly as it is under floor of an under seat locker, but as boats go not too bad
 
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