You mean you want to increase the volume of water. After your PRV valve the press. is the same all through the house, if your hw pipes are partly stoppedup your vol. will cut down so check all your areaters on faucets and check under the sink with your stop, take supply loose and see if you have a lot of water at stop, if so then it is something in your faucet needs to be done. Clean it out are new parts.
Art retired plbg