Reactive force for a pressure relief valve flowing non compressive liquid

[abehong]

Hello:

I need some instruction on how to calculate the reactive force for a pressure relief valve flowing non compressive liquid . The formula provided in API 521 seems to only apply for compressive fluid. Thank for your response.

 

[chicopee]

I would think that it would not be any different then figuring out reactive forces on an elbow which you had to figure out when you took Statics and Dynamics.

 

[C2it]

Change of momentum is the basis of this.

Some PRV manufacturers offer equations in their catalogues.

 

[FredRosse]

For a liquid discharge, the force is the liquid mass flow rate multiplied by the change in V, in this case the term V is a vector, thus giving the direction of force. Be sure to use proper units, this is a dimensionally correct formula in any rational system of units.