Pressure in a piping systems 3

[SHS100]

Folks,

I am new here. My question relates to the pressure at any point/location in the system.

So the following is a description of the system - I have a tank of water piped to a centrifugal pump that delivers to a number of users points. The centrifugal pump will be set up to maintain a pressure setpoint of 10BarG, this is controlled via pressure switch near to the discharge nozzle of pump. When the pump pressurises the system to 10BarG it then stops, the system is at 10BarG and if there is no demand or no users taking water then there is no flow in the system. I only have a pressure guage fitted near to the discharge of pump and no other guages downstream. Considering that there is no change in elevation throughout the system - is the pressure at any point in the system at 10BarG??

 

[1503-44]

Yes. The same in a no flow - static system. It will increase by fluid density x change in elevation, if pipe elevation drops and decrease if pipe elevation rises.

Reality used to affect the way we thought. Now we somehow believe that what we think affects reality.

 

[LittleInch]

I agree - the anwer is yes.

This is though not a good system. If you don't have a bladder or accumulator, the pump will be constantly turning itself on and off as only a very small water loss can create a very big pressure drop or rise. Also as soon as any one wants water the pressure drops to near zero befor ethe pump has a chance to start then creates a big spike in pressure as it kicks in.

It also implies your non return valve on the pump is 100% sealing - very few are.

but maybe you have all these things - it seems like a very simple / basic question I would expect people learnt in high school?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[itsmoked]

Bad on so many levels. You could end up with a higher user and a lower user opening valves at the same time and having backflow. You either need a VFD based pressure pump or a bladder tank as Little suggests.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[1503-44]

There are billions of simple home water supply systems like this that just just a hi/lo range pressure switch to start/stop the pump while allowing some depressuring to occur between pump runs. Start at 20 psig and stop at 28 psig may be all you need. But are you asking about all that???

Reality used to affect the way we thought. Now we somehow believe that what we think affects reality.