Compressed air in an enclosure.

Over the time I've been hanging out on here I don't recall this coming up.
How many people have air sol. valves in a cabinet?
I'm sure there are some, so what are the common thoughts on
providing a "vent" of some kind sized to handle a line break?
Better yet is there any pictures of a panel that had no vent with a line break?
I have started seeing more equipment that has air feeds in them
with no vent and the pressures those cabinets can see is
tremendous. I don't mean the "dump" port on the valves
themselves going outside the cabinet because they have to.
What I mean is a vent that is there for a line break inside the
cabinet.
I'm talking to the designers about this but so far from what I'm
told there is one that does not believe it is necessary.
The cabinet we use are mostly hoffman stainless because of an
acid enviroment in one of our dept. which is why the valves are
in a cabinet.

Drewcrew6

DrewCrew6

We also have quite a number of valve terminals in panels and I would not dream of building one of these without a vent for exactly the reason you refer to. I would normally fit a vent/drain line in the bottom of the panel so that it can also act as a drain for any water or condensation which might accumulate there.

One of our 'expert' suppliers of hydraulic and pneumatic systems provided us with an air cylinder control box that had the solenoids exhaust inside the stainless steel box. No vent because it is ClassII DivII coal dust environment. People wondered why the door was bulging out rythmically. On top of the box being too small, I had no choice but replumb the whole deal. Just had to use ClasII DivII rated solenoid valves.

Brian.

I agree Andybr. I am really hoping someone has pics and specs of this senerio gone wrong.That might help me convince certain people.

I'm confused Sliver?

Considering that a 2" cylinder has over 300 pounds of force when supplied with 100 pounds this is a disaster waiting to happen in my opinion.

Drewcrew6

Enclosure Vent

We still do a lot of Air Logic work. The Air Logic modules are located in an enclosure. We vent the enclosure using a bulk head fitting and muffler. The external side of the bulk head fitting has the muffler and the internal side of the bulkhead is left open to the inside of the enclosure.

I'm not sure but there may be a law requiring a vent.

Compressed air in a sealed enclosure. Aren't you turning it into an air tank?

They require pressure relief valves. I don't like air solenoids in panels but you've got my curiousity up. I'll see if I can do a little looking

Your confused? You should be, I only got part of a sentence in and accidently posted. Boy you guys are fast!

Brian.

What type of vent should one use on a stainless Nema4x panel?

Yo Stoop Dats A Killer Question Wish I Could Help Im Just Clueless This Tyme Iight Peace Home Skillett!

We had some enclosures at one time with solenoids inside the cabinet. We obviously vented the dump side of the valves to the outside of the panel.

I wonder if you could maintain your CII/DII rating by installing a pressure relief valve to atmosphere? The valve would only open if cabinet pressure exceeded, say, 4 or 5 psi.

Ok, I haven't found anything legally yet, but I did find a companies equipment specification requiring that solenoid panels drain have a catch for oil and other contaiminent for environmental reasons. They never mention requiring the drain though, I guess it is just assumed you would have one

Valves in a closed cabinet is crazy! Especially 100 PSI, or more, in any case.

In many cases, operators are not allowed to open cabinets to see what is happening. In many cases, with minimum over-night maintenance coverage, operators are allowed to change valves when they see that they are defective... they can't do that in cabinets that they are not allowed to open.

I believe that valves should always be exposed and as close as possible to the load. Of course, the valves should have an indication of the intended operation (indicator light). The operator can then see what the valve is "trying to do" and what it is, in fact, doing. If the valve doesn't do what it is trying to do (as indicated at the valve)... replace the valve. In that case, any busted air-lines go to atmosphere. They are not constrained within a closed cabinet where they can develop into a danger for anyone who happens to be walking near-by.

Terry Woods said:

Valves in a closed cabinet is crazy! Especially 100 PSI, or more, in any case.

In many cases, operators are not allowed to open cabinets to see what is happening. In many cases, with minimum over-night maintenance coverage, operators are allowed to change valves when they see that they are defective... they can't do that in cabinets that they are not allowed to open.

I believe that valves should always be exposed and as close as possible to the load. Of course, the valves should have an indication of the intended operation (indicator light). The operator can then see what the valve is "trying to do" and what it is, in fact, doing. If the valve doesn't do what it is trying to do (as indicated at the valve)... replace the valve.

Click to expand...

If we are going to address that might want to look at THIS topic

I can see why the valves are in an enclosure due to the enviroment we have. But there is no reason that a vent should not be on the enclosure.


Does no one have any pictures of this?
Has anyone everseen thisafter a failure?

Out of all the posts maybe this is not the issue I believe it to be.

but 36 x 36 door = 1296 x 4psi = 5184 pounds of force
change that to 100 psi and it is over 64 TONS of force.


Drewcrew6

You're not likely to get a seal on the panel.
If you have a typical conduit feed, the air will go down the conduit, and blow out the electrical panel.