Settling Chamber

[hollywood63]

Well gathering info on building a flow bench I noticed that a "settling chamber " is being used. I can't get a piece of 6 in. pipe but I can get a 12 in. piece. Is this to big? Being that I'm not sure at what a chamber does I have to ask. I was then going to neck it down to a 2 in. pipe with a annubar. I will only be testing valves that are 1.6 in. and 1.94 in. does all of this seem like I'm on the right track ???

Thanks Art

[bruce]

Yes you're on the right track to build a pitot style flowbench.

[hollywood63]

Thanks Bruce Is a 12" pipe to big?

[hollywood63]

Sorry to keep on the chamber thing but is a settling chamber really needed with a pitot style bench? All of the info I'm finding says that a chamber is helpfull with a orfice style bench.
My problem is I'm having sort a problem coming up with a leak proof design mounting a 12in. pipe and getting the tappered end to neck down to my 2 in. pipe. If I were to us a 4 in. pipe about 20 in. long would this be enough or is this just a matter of opinion?
Thanks Art

[bruce]

A nice size space (read settling chamber) under your test peice allows you to find a good location that is not affected by velocity flow to take your static pickup for flow depression. From my testing the goal is to find this/a location no matter what size pipe you use. Try and keep the static pickup hole as small a diameter hole as possible so it does not pickup velocity flow and have it effect your static reading (I use a #42 drill). Hope that clarifies it some?