The Official Mercdog Flowbench thread - The Official Mercdog Flowbench thread

[Mousehouse1]

Does it matter how big the hole is behind the orifice disk?

What is everyone using for a front panel on their mercdog/msd benches? I am currently using a piece of plexi-glass but when I do a leak test it is moving a little bit. I thought about switching to a piece of aluminum. But how thick should the aluminum or steel be?

[Mousehouse1]

What is the best way to cut the holes when you are making a orifice disk with 3-5 holes in it?

I have used hole saws but there has to be a better way.

[84-1074663779]

I would expect there would be some sort of turbulent wake spreading out on the downstream side behind the orifice plate. As long as whatever is behind the orifice does not intrude into this wake, it should not effect the flow coefficient ?

It may be best to bore individual orifice diameters in the lathe, and then attach these onto the main disc or turret somehow.

[Mouse]

You need some clearance of supporting structure, not as much as on the leading side. But if you intend on bi-directional use, you will need a lot of clearance.

Making an orifice is difficult at best. I have found the best way on thin metal is to cut the hole smaller than intended, get close with a grinder and small stone or carbide bit, then finish to size very carefully with a hand half round mill file. Tedious, but effective. Try not to roll the edges or dent them. Keep a nice square cut for bidirectional use.

John

[Mousehouse1]

After talking to Larry, you and Bruce I think I am going to use several orifice plates and that should solve all of my orifice area leakage.

I plan on using an o-ring to seal the orifice plate to the bench and then install some sort of clamping fixture to the top of it. I haven't decided how I am going to do that part yet. Still coming up with ideas.

[Mousehouse1]

How thick should the front aluminum panel be? I am currently using a 3/8" piece of plexi-glass but it flexs a little when I do leakage testing. Thought about replacing it with a piece of aluminum.