water pressure 1

[wedostr2]

I'm looking for the water pressure drop across a backflow preventer on a 3/4" to a city main with delivered pressure of about 75 psi. Can anyone stear me to that information?

 

[KiwiMace]

Exactly zero when there is no flow. For all other flow rates, refer manufacturers catalog.

 

[MTES93]

Typically around 12.0 psi for most flow rates if device is reduced pressure type. See link...

If not RP type, you should be able to back out of this link and find the type you have...

http://media.wattswater.com/ES-009.pdf