Hydraulic transients for diagnosis of inline valves in water transmission pipelines

Abstract

This paper presents a new non-intrusive methodology for testing the seal quality of inline stop valves. An inline stop valve is a common element of the water supply system, both in large diameter transmission pipelines and in distribution networks. A good quality valve seal is essential for executing an isolation procedure. The proposed technique uses an artificially generated hydraulic transient to test the valve seal. The valve resistance coefficient, the diameter of the orifice that is equivalent to the open area of the valve and the discharge rate through the valve are derived based on the reflection of the transient wave from the closed valve. The method provides a quick and inexpensive way of identifying inline stop valves that fail to seal and allows operators to rate their condition without internal access to the pipe. This technique may provide a useful diagnostic tool for planning the replacement of valvesBursts; detection;, monitoring; transient response; water hammer; inverse analysis