Once a gas cylinder is empty of pressurized gas at the end of use, if the valve is left open, there is nothing to prevent anything from the atmosphere entering the cylinder throught the valve.want to know more
In many situations, where multiple cylinders are connected together on a manifold, active backflow of customer process fluids into a near-empty cylinder is a significant possibility.want to know more
Historically the Gas Industry has trusted users not to allow backflow
or atmospheric contamination into cylinders, while cylinder fillers
deploy prefill inspection procedures to identify potentially contaminated
cylinders returned from customers.
However, it’s not an ideal solution, and incidents caused by backflow of contaminants into cylinders do happen, highlighting the benefits of an automatic backflow prevention device within a valve.
Retaining the last few psi or bar of pressure behind a Residual Pressure Device (RPD) in the cylinder at the end of it’s customer use cycle is possible with the RPD incorporated within a standard-sized valve, referred to as Residual Pressure Valve (RPV).
In addition to reduction of work, cost and risk discussed above, use of an RPV also deters illicit filling of your cylinders, as a bespoke filling adaptor will be required to access the cylinder for filling.
|Part. No.||Gas||CGA Outlet||CGA Inlet||Working Pressure||Burst Disc (psi)|
|1777677||Air||CGA 346||3/4" NGT||3 000 psi||4 000 psi|
|1777630||Argon/Nitrogen/Helium||CGA 580||3/4" NGT||3 000 psi||4 000 psi|
|1777631||Carbon Dioxide||CGA 320||3/4" NGT||3 000 psi||4 000 psi|
|1777629||Oxygen||CGA 540||3/4" NGT||3 000 psi||4 000 psi|
1. As part of the prefill procedure, it’s easy to make a functional check on the condition of the RPD within the RPV valve to ensure the benefits are being delivered.
2. Fill connectors designed to enable only appropriate operators to open RPV valves deter illicit cylinder filling
3. For all de-valving operations, care needs to be taken to ensure that the cylinder contains no pressure. In the case of RPV valves, the residual pressure retained by the RPD mechanism inside the RPV valve must first be removed using the approved filling adaptor.