Why would the reducing valve (RV_, CRV_) make strange noises?
This problem could be cause by a few things. If the reducing ratio is larger than 10:1, there could be an abnormal sound. Reduce the pressure is 2 stages, so as not to shock the system. The noise heard might be “water hammer”; it is suggested that a steam trap be installed before the valve. If there is a quick responding valve near the reducing valve, the quick responding valve should be as far away as possible from the reducing valve. And if the valve is oversized, it is important to verify the sizing and change the valve if needed.