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Pressure Regulating Valve and Pressure Reducing Valve

Pressure Regulating Valve and Pressure Reducing Valve

Pressure Regulating Valve and Pressure Reducing Valve

Dear All ,

I Am little confused between these two valves , Pressure Regulating Valve and Pressure Reducing Valve .

as per study i think both are same but why different names , Please review the Attached Drawing , the Pressure Reducing Valve is been only

installed to the hot water supply Risers which Goes to the Ground Floor and Lobby only , not to the others ( i think we need more pressure in there risers due to long distance why install pressure reducing valves?? )

and for the Pressure Regulating Valves , they are installed on the Hot water return line just before the Hot water circulation Pumps ,
( can the system run with out them and what purpose they are fulfilling )

please advice ,


Attachment : http://www.filedropper.com/01-m4-ws-109

RE: Pressure Regulating Valve and Pressure Reducing Valve

I can't open your file attachment - please use the attachment link underneath the posting box.

However the two terms are quite close together as essentially it is a similar valve, just depends on how it is controlled, but can be interchangeable. the trick is to be consistant in the description for a particular system.

Pressure regulating tends to control either the upstream or downstream pressure to a set amount.

Pressure Reducing valve tends to be limited to controlling downstream pressure or reducing the pressure by a fixed value, though this might then be called a differential pressure reducing valve - confusing eh?

Without the diagram it's difficult to say which is which, but better to simply call them control valves and show what its function is, which can be from multiple inputs, bit only one will be controlling at any one time.

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

RE: Pressure Regulating Valve and Pressure Reducing Valve

In the drawing, the "pressure reducing valve" is what is normally called a "pressure regulator" and is used to control downstream pressure.

The "pressure regulating valve" in the drawing is what the world calls a "back pressure valve". Whoever learned Viso last week to prepare this drawing is creating a whole new world of confusion with this drawing. It could easily be that this BP valve is there to try to keep the hot water returns from flashing.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

RE: Pressure Regulating Valve and Pressure Reducing Valve

I suspect that the valves on the return leg are simply there to allow adjustment of the flow so that each return leg when there is no flow out the far end is more or less equal. Hence each leg stays full of hot water. A very high waste of energy goes on with systems like this unless you seriously insulate all the pipework involved.

The pressure regulating valve on the leg going to the basement is just so that you don't overpressure the basement piping.

So yes the wording is odd because in order to regulate the pressure you need to reduce it. A valve cannot generate pressure only reduce it.

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

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