Shurflow pump

[TCG]

Hi Can you good guys help?
I am looking to purchase a spare pump, been online and cannot find exact replacement, the ones i am seeing have reduced Bar presure and deliver less water per minute. my pump is 20psi could i fit a 30psi to increase presure and flow rate?

 

[WillH]

It matters little what the pressure and flow rates are as long as you are happy with what the pump delivers.

 

[autorouter]

It's OK as long as the boiler and pipes can tke the higher pressure. Truma boilers can take 2.8 bar (about 40 psi) but best to double-check the spec.

 

[funflair]

Just increasing the pressure does not increase the flow rate, the pump you show is 7.5 l/min and I think most Shurflo are 7.0 l/min and 20psi so close enough in my book, I would keep the pressure the same personally.

Martin

 

[pappajohn]

Just increasing the pressure does not increase the flow rate, the pump you show is 7.5 l/min and I think most Shurflo are 7.0 l/min and 20psi so close enough in my book, I would keep the pressure the same personally.

Martin

try explaining that to one or two members if you can.... And have the patience.

Even though I posted the pressure and flow rate from two shurflo pumps...30psi 7ltr....20psi 7ltr....they still insisted higher pressure meant higher flow.

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[funflair]

try explaining that to one or two members if you can.... And have the patience.

Even though I posted the pressure and flow rate from two shurflo pumps...30psi 7ltr....20psi 7ltr....they still insisted higher pressure meant higher flow.

Maximum flow rate of the pump will be measured with no restrictions, ie no pipework bends, couplers or shower head. The maximum pressure of the pump will be measured with full restriction to the flow.

So the pressure does not change the flow rate of the "pump" but it does alter the flow rate of the "system" as a greater pressure gets past the restrictions easier and allows more flow at the exit.

So I may or may not have discredited my original statement

Martin

 

[andy63]

try explaining that to one or two members if you can.... And have the patience.

Even though I posted the pressure and flow rate from two shurflo pumps...30psi 7ltr....20psi 7ltr....they still insisted higher pressure meant higher flow.

Generally speaking that is the case...
In any given system if there is no change to the size of openings and length of pipe etc a increase in pressure will result in an increased flow..
That doesnt mean you cant get two pumps to operate at the same rate of flow at different pressures by design...
Andy

 

[pappajohn]

If it delivers 7 liters a minute it delivers 7 liters a minute.
My argument was that 7 liters is a finite amount regardless of the pressure behind it.
It cannot move more than 7 liters in one minute either through a 3" pipe or a drinking straw, but the water pressure differential will be vast between the two.

 

[pappajohn]

That doesnt mean you cant get two pumps to operate at the same rate of flow at different pressures by design...

That was my main argument but it seemed to fall on deaf ears.

 

[2657]

If it delivers 7 liters a minute it delivers 7 liters a minute.
My argument was that 7 liters is a finite amount regardless of the pressure behind it.
It cannot move more than 7 liters in one minute either through a 3" pipe or a drinking straw, but the water pressure differential will be vast between the two.

No it can't deliver more than 7l/min but it can deliver a lot less,if the pressure is capped at 20psi then the flow rate through the straw will be a lot less.

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[pappajohn]

No it can't deliver more than 7l/min but it can deliver a lot less,if the pressure is capped at 20psi then the flow rate through the straw will be a lot less.

At no point did I say it couldn't deliver less.

Anyway, I said all I had to say on the other thread.
I've been to Coventry and its a sh!thole.