I just ran a new water line to my home. Replaced 3/4 poly butle with 3/4 pvc. Almost immediately started getting water hammer. It only happens when you run the water not when shutting it off. I can turn down the flow at the gate valve and it will stop but as you turn it up I can set it where the water keeps running in the kitchen but I can here the regulator cuttung the water on and off. I mean I'm standing right at it the gate valve its just a foot from the regulator and you can hear the water flow going on and off at the regulator. Is my regulator bad or is there air in my pipes?