- Report #: NT VVS 012
- Approved: November 1981
This method is to be used for testing and estimating the noise produced of water running through valves in water supply systems. Present methods in use for such testing do not include procedures, for determining whether the valve produces more or less noise when the static pressure upstream the valve is changed, without changing the pressure drop and, thereby, the rate of flow through the valve.
Experience from practice, as well as from laboratory measurements, (1) in Annex A prove that, depending on the construction of the valve the actual noise level can either increase or decrease when the static pressure upstream and downstream the valve is increased to a higher level.This can happen even while maintaining the pressure drop over the valve at a constant rate.
It is the objective of this method to include the measurement of this particular property of the valve.