DonadonSDD excess flow valves have been designed to prevent pressure accumulation in the space between the rupture disc discharge and the second safety device.
Since rupture discs are differential pressure devices, avoiding pressure accumulation is essential to ensure correct disc opening at the desired bursting point. Excess flow valves are usually used when rupture discs are used together with a safety valve or when installed on multiple rupture discs in series. Excess flow valves close when exposed to the rupture disc discharge flow.
DonadonSDD excess flow valves are available in ¼” or ½” versions and can be supplied with T connectors, nipples and pressure gauges upon request. All accessories are made of stainless steel.