Test Points (or Test Plugs) are normally used in pairs to measure the differential pressure or pressure signal across a flow measurement device in heating or chilled water systems.
Test points are frequently supplied with, or fitted to flow measurement devices such as metering stations, fixed orifice and variable orifice balancing valves and pressure independent control valves (PICV).
The self-sealing test points are fitted with a sealed captive cap and red or blue plastic strap. Conventionally, the test point with the red strap is fitted upstream and the blue strap downstream. Pressure probes are inserted into the self sealing elastomer core in the test point and the probes are more commonly attached to an electronic manometer.
Probes with integral pressure gauges or thermometers may be inserted into the points to establish local operation conditions.
Single Test points are also used at convenient locations in water distribution systems to enable pressure and temperature measurements to be taken. This also allows pressure differential measurement to be taken between two specific points which is beneficial when, for example, actuated control valves are installed, which only close against low differential pressures.