DWPC,

Each size pressure regulator lists the flow rate for the pressure range drop it produces. If you require a certain flow rate at the downstream side of the regulator look for the size regulator that gives you that flow rate. Your pressure is high so you may need to put two pressure regulators in series to provide two drops to the desired pressure and the demand flow. You can also put the PR in parallel to provide the full drop and get the rated flow from both PRs. Does anyone agrees with this because it is JMHO. Someone may have more detailed info on this. This is a general overview. This info is for a direct-operated PR type. Aloha

It will be less. How much less will depend on the regulator. You will get more flow through a one inch regulator than you will through a three quarter inch regulator of the same kind. I can't help with how much less.

It would be easier to reduce trhe pressure with an additional station or two and you wouldn't lose any flow.

Zeuspaul

zeuspaul: By "stations" do you mean nozzles?

Yes. To reduce the pressure you can add nozzles or increase the orifice size of your existing nozzles.

Zeuspaul