What's the difference . Water pump spec?

[normanandsue]

My current defunct freshwater pump is marked ,84 bar. The one I am looking to replace it with is marked 1,4 bar. Can one of you techies tell me what difference it would make and should it be OK as a replacement.

Many tia

 

[Lenny HB]

Obviously the pressure is a lot higher on the replacement but how does the flow rate compare?

 

[normanandsue]

Obviously the pressure is a lot higher on the replacement but how does the flow rate compare?

Don't know as I haven't fitted it yet. What concerns me is, will the replacement pump increase pressure in the system and possibly cause pipe connections to burst.

 

[Lenny HB]

Don't know as I haven't fitted it yet. What concerns me is, will the replacement pump increase pressure in the system and possibly cause pipe connections to burst.

Should be OK that's about 20psi about the same as the smallest Sureflow pumps. No good having high pressure if the flow rate is naff.

 

[normanandsue]

Should be OK that's about 20psi about the same as the smallest Sureflow pumps. No good having high pressure if the flow rate is naff.

How would I know what the flow rate is without fitting it?

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[Ernesto]

We've fitted and experienced a similar increase in pump pressure as the original fitted to our van wasn't up to the job - no problems so far

 

[Diabalo]

Flow rate should be indicated somewhere

 

[Lenny HB]

How would I know what the flow rate is without fitting it?

Should say on the pump or in the spec.

 

[PeteH]

My current defunct freshwater pump is marked ,84 bar. The one I am looking to replace it with is marked 1,4 bar. Can one of you techies tell me what difference it would make and should it be OK as a replacement.

Many tia

What Maker?. Shureflow for example have a web site and the full spec; of all their pumps.

 

[tonyidle]

The major consideration when buying a pump is flow rate. This affects how fast the water leaves the taps. If your system is controlled by tap microswitches then pressure isn't a consideration. Pressure is measured with the pump outlet blocked off and is the max value achievable by the pump. As such it only matters if you are on a pressure-switched system and all that matters is that it is more than the pump it replaces so you can be certain it will operate the pressure switch. System pressure will only rise until the pressure switch turns the pump off and pressure switches, whether built-in to the end of the pump or not, are adjustable. So, to summarise, if you have a pressure system pre-set to a particular pressure you can install the pump you suggest then turn the pressure down if you wish. As has been suggested you could leave it set as out of the box with no ill effect. If you have a microswitch system pressure doesn't matter. In both cases make sure the flow rate matches or exceeds that of your existing pump.

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[PeteH]

The "Trail King" series of pumps are fitted to many R-V`s and Motorhomes (I have a big box of parts from various "dead" ones) the most common seem to be 1.7l/min flow rate. but the one from the last R-V was 2.4L/min. (from Memory) The pressure control is usually adjustable.

 

[autorouter]

There is one possible problem with the pressure, and that is the water heater may have a maximum pressure spec. Our Truma has a spec of 1.4 bar, so a higher pressure pump presumably has the risk of activating the pressure release valve and causing leakage. There are many different units for pressure, but as a guide, 1 bar is about 15 psi (14.7 I think).

There is pressure drop along narrow pipes, so if like ours the sink or water heater is on the opposite side to the water tank there are long pipes that need high pressure to get a decent water flow. The advertised pump flow rate is only good for a short pipe length.

I think the Trail King flow rates are more like 7 and 10 litres per minute.

 

[normanandsue]

Flow is 19/l PM sames as pump being replaced. Sorry didn't realise when asked previously about flow it was the number of litres per minute.
This is why us techie dinosaurs in our ignorance need and appreciate the help of our techie friends

 

[normanandsue]

Thanks to all of my techie funster friends my new pump is fitted and all is working fine. All you comments and advice was helpful and much appreciated