Piping - Eccentric Reducers

There had been quite a few threads on this topic like this orr this

Use search feature on Right side with Eccentric reducer. If you don't get what you are looking for then put the question here. Else it becoomes unnecessary repetition for all.

UD15

After searching old threads I could find eccentric reducers topic as applied to pump suction only.

Whereas what I need is for the case of Control Valves in piping systems.

thanx

Flat at the bottom - At a control valve you may want to trap any air (or lighter fluid) and expel it via an air release valve before it is introduced in the system.

This is not true in cases where the intruder fluid is heavier than the fluid to be controlled.

What is your situation ?

I've always used concentric reducers with control valves (even in horizontal pipes) and never had any problem. There's usually plenty of turbulence at a control valve, so any gas is entrained and carried away.

Cheers..........Codey

We usually use concentric reducers for the control valves and additionally at 5D distance between the valves and the reducers.

The various literatures too mention the concetric reduceres (eg emerson process cvh99

Page 114 The most commonly used fitting in control valve installations is the short-length concentric reducer.

Also you may look at the sample problems at page 117.

Eccentric reducers (bottom flat) are useful if the the equipment (and that includes the valve) encounters 2-phase flow (Gas and a liquid). If it is solid and liquid it may be otherway round. It is to ensure that the liquid does not accumulate. This may result in water hammer as the flow may alternate between liquid and gas. There may be rare cases where it would be advantageous to have eccentric reducers with top side flat.

UD15