Divemaster-K
Guest
Anyone ever built a small compression test tank for computers and camera housings?
Compression test tank?
- Thread starter Divemaster-K
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Yes, several sizes.
Gary D.
Gary D.
I sectioned the bottom off an aluminum 80 tank for mine.
It failed for neck cracks at the threads.
Mike D
It failed for neck cracks at the threads.
Mike D
CivilE
I break things
What kind of hardware did you use for it Mike? I have a section of 8" C900 pvc that I was considering making a light duty one out of.
Jason
Jason
FatRob
Contributor
I've made a few..
The first was a piece of 3" sch80 PVC pipe, though SCH40 would work. I cut it square (on the lathe) cut out two plastic endcaps, made some rubber gaskets and used tie rod style bolts (1/4-20) x 4. to clamp it together. You can either drill and tap for an LP quick disconnect fitting, or else use NPT fittings to make an Air input output orifice.
The second I use at work for pressure testing oceanographic instrument housings. It's a piece of steel sch80 pipe 8" size, with a plate welded over one end, and a flange on the other. A blanking flange is used to seal the top, there is a 1/4 NPT port for shop air. a valve to allow me to keep the pressure up... and a gauge to allow me to read the pressure.
The trick to both of these is to fill the thing with water right up to the top, then you only apply compression to a very small volume of air, water being virtually incompressible will not expand explosively if you get a failure.
The small plastic case will take 200PSI which works out as around 13.5 ATM or 135m or 445 feet sw.
The larger one should be good for over 500PSI though I don't currently use it to that spec, because I don't need to. I've done tests to 100msw for days at a time.
The main problem I had with the plastic version is that the gasket tends to compress and extrude. A better approach would be to turn a groove in each end of the tube for an o-ring.
Hope that helps.
Rob
The first was a piece of 3" sch80 PVC pipe, though SCH40 would work. I cut it square (on the lathe) cut out two plastic endcaps, made some rubber gaskets and used tie rod style bolts (1/4-20) x 4. to clamp it together. You can either drill and tap for an LP quick disconnect fitting, or else use NPT fittings to make an Air input output orifice.
The second I use at work for pressure testing oceanographic instrument housings. It's a piece of steel sch80 pipe 8" size, with a plate welded over one end, and a flange on the other. A blanking flange is used to seal the top, there is a 1/4 NPT port for shop air. a valve to allow me to keep the pressure up... and a gauge to allow me to read the pressure.
The trick to both of these is to fill the thing with water right up to the top, then you only apply compression to a very small volume of air, water being virtually incompressible will not expand explosively if you get a failure.
The small plastic case will take 200PSI which works out as around 13.5 ATM or 135m or 445 feet sw.
The larger one should be good for over 500PSI though I don't currently use it to that spec, because I don't need to. I've done tests to 100msw for days at a time.
The main problem I had with the plastic version is that the gasket tends to compress and extrude. A better approach would be to turn a groove in each end of the tube for an o-ring.
Hope that helps.
Rob
I havn't really built a compression test tank, but I have built a small ROV . When I need to pressure test something, I just strap it to the ROV and send it to depth. It puts the item being tested at the depth needed to be tested for, as well as other factors such as salinity, temperature, etc. Its also really useful ( not to mention fun sometimes) to be able to watch the test through the ROV's camera.
Smedja
Registered
I have seen the problem when a friend tested some lamps for a UV film.
He was using a HP washer for pressurising. This makes the thing more ore less risk free. An other way too rise the pressure might be to screw a long screw in to the tank. Hiss tank did not hold fore al the psi the HP Pump delivered. Try to avoid annoy sharp corners. Therefore a pipe is a god peace of material fore a chamber.
In some cases use vacuum inside a device for testing to avoid water entering in to your stuff.
To find steel for tank making lock at the scrap yard from some refinery. It takes heavy steel to enclose HP and make shore to use big enough bolts. If a bolt snaps I reckon it can fly off with some power even if there is no reel expansion when some thing brakes from water psi.
He was using a HP washer for pressurising. This makes the thing more ore less risk free. An other way too rise the pressure might be to screw a long screw in to the tank. Hiss tank did not hold fore al the psi the HP Pump delivered. Try to avoid annoy sharp corners. Therefore a pipe is a god peace of material fore a chamber.
In some cases use vacuum inside a device for testing to avoid water entering in to your stuff.
To find steel for tank making lock at the scrap yard from some refinery. It takes heavy steel to enclose HP and make shore to use big enough bolts. If a bolt snaps I reckon it can fly off with some power even if there is no reel expansion when some thing brakes from water psi.
Smedja
Registered
If diferentsial presurs ar cept and nott are canching itt is not leaking. Wohewer some time produker fore deap vater nead oter taitnings for lov prtshr changes and be hard to keap vaterproow at the syurfes And therfore itt might be importent to titen bothfor low and hard pessur.
:mooner:
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