Relief Headers

<<It is often desirable to combine the discharges from safety relief valves into common pipe headers. The common headers are piped to a safe location, with provision for collecting liquid relief and treating vapor discharge.

VentManifold is an Excel spreadsheet template that calculates the backpressure that develops when simultaneous vents discharge into a common header. This is important because relief valves are designed to operate within specified back pressure limits.

This page discusses the design of relief valve discharge manifolds.

A relief valve discharge header takes the form of a tree. Each valve, vent, or rupture disc is piped to a branch; branches may combine into larger branches. Finally, the main trunk is reached, discharging to atmosphere (perhaps by way of a large knock-out drum or scrubber).

After the equipment arrangement is established, a rough pipe routing is made. Then the piping may be sized using the methods presented here. A detailed routing is designed, being sure that there are no pockets where liquid could obstruct the flow. Sizing should be checked with the detailed routing, again using the procedures presented here.>>

http://www.chemengsoftware.com/techinfo/headers.htm Received on Thu Jan 25 20:44:00 2007