Eccentric reducer

[B.L.Smith]

Hi

What type of reducer should we use before and after in-line control valve in liquid systems? (Eccentric top flat, bottom flat or concentric),and Why? Could u mind address a reference for this issue?

 

[bimr]

Probably does not matter unless you have some type of high performance application. Perhaps you would like to add some application details so that someone may state an informed opinion.

 

[pennpiper]

I do not believe anyone can address a reference for this subject. It is not really an issue as far as the industry is concerned.
I would suggest, if you took a survey of all the Control Valve manifolds in all the world you would find that Concentric reducers are the only ones used.

prognosis: Lead or Lag

 

[Pumpsonly]

The main concern in selecting type of reducer in pipe line is to eliminate air pocket in the pipe line. If your pipe run is horizontal or lower than the reducer, you use flat top. If going up wards , you use flat bottom or concentric. Concentric may not allow you to drain the pipe completely.

 

[LittleInch]

I've seen all types, mainly bottom flat (means the pipe supports are all at the same level and easy draining), and concentric (gas and liquid, especially when very close to the valve, but only occasionally top flat.

It's more about your piping layout and where your vents and drains are than anything else and only you know that.

As pennpiper says, the majority are probably concentric because it looks good and there is no disruption to flow. Either that or bottom flat a few pipe diameters away from the valve so you don't get any strange vortices or anything.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[BigInch]

At the high velocities near most control valves, trapping gas bubbles isn't going to be the biggest problem at hand.

Learn from the mistakes of others. You don't have time to make them all yourself.