Compression test tank?

[Hoosier]

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:

Thanks, but please re-phrase your post in a plain English...... Sorry. I can't follow you....

 

[Charlie99]

In some cases use vacuum inside a device for testing to avoid water entering in to your stuff.

And there are commercial water waterproof testers that suspend the watch in air a pressure vessel half filled with water. The air pressure is pumped up to 3 to 6 bar range and held there for a while.

Then without removing pressure, the watch is lowered into the water. Only then is the pressure reduced. If the watch is not airtight, then it will have pressurized and now the air will come back out and be detected as bubbles as the chamber pressure is reduced.

The advantage is that even with a failed seal the inside of the watch will stay dry.

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This same technique could also be used for a 1ata max test, with the watch starting at 1ata, lowering it into the water, and then pulling a vacuum on the chamber.


Hoosier, maybe this is what Smedja is referring to.

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There are also commercial dry waterproof watch testers that either apply pressure or pull a vacuum and look for case deformation. If it doesn't deform a bit from the pressure differential, then you know the watch isn't airtight.

 

[Hoosier]

And there are commercial water waterproof testers that suspend the watch in air a pressure vessel half filled with water. The air pressure is pumped up to 3 to 6 bar range and held there for a while.

Then without removing pressure, the watch is lowered into the water. Only then is the pressure reduced. If the watch is not airtight, then it will have pressurized and now the air will come back out and be detected as bubbles as the chamber pressure is reduced.

The advantage is that even with a failed seal the inside of the watch will stay dry.

-------------------

This same technique could also be used for a 1ata max test, with the watch starting at 1ata, lowering it into the water, and then pulling a vacuum on the chamber.


Hoosier, maybe this is what Smedja is referring to.

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There are also commercial dry waterproof watch testers that either apply pressure or pull a vacuum and look for case deformation. If it doesn't deform a bit from the pressure differential, then you know the watch isn't airtight.

Thanks for your explanation and re-phrasing.


One further question on your reply.

What I was told is the modern sensor on the computer and gauge should be wet in the process of pressure test. Otherwise, the sensor will be damaged.

Any idea? Is there any safety margin on the sensor for this dry test, such as 1 ATM?

 

[Charlie99]

What I was told is the modern sensor on the computer and gauge should be wet in the process of pressure test. Otherwise, the sensor will be damaged.

Any idea? Is there any safety margin on the sensor for this dry test, such as 1 ATM?

I don't know the reason behind the recommendation to always test computers submerged. I suspect that the potential problem is getting air into areas that are supposed to be sealed, and then getting a reverse block on the way back up. I.E., the computer might be watertight, but not necessarily airtight. Just a guess though.

 

[TishaDee]

Hi guys! Pardon the intrusion and my ignorance on the matter. But I love DIY stuff and as I was reading this a thought came to my mind...could a pressure cooker (the heavy steel pans with the clamp down lids that withstand amazing pressure when heat is applied used for cooking) be modified to work for this use? Obviously you wouldn't use heat but I know they have a vent valve which you might be able to use for adding pressure or attaching a pressure gauge... If you don't know what type of pan I'm talking about ask the women in your life, chances are good she has one.

Any thoughts on this?

 

[Hoosier]

A pressure cooker at the kitchen is upto 1 ATM. It isn't enough range for the pressure pot.


Guess what! You aren't the first one who thought it....:blinking:

 

[5513]

Try this.

Homebrew Pressure Tester

 

[TishaDee]

Wow, at least I'm not far off the mark! So is it the size of the pan/tank or the pressure the lid can withstand that dictates how many ATM's of pressure it can withstand?
Is there a formula that you use to calculate how many ATM's it's equivelent too? Sorry for what might seem like dumb questions, but my interests are varied and I one day of dream of having a complete repair/service shop in my garage...

Thanks in advance guys!!

 

[Hoosier]

Try this.

Homebrew Pressure Tester

Yes, the pressure pot can be made of a PVC pipe. The smaller diameter you are using, the higher max. pressure you can expect. However, the working pressure should be 1/4 or 1/3 of the max. pressure to CYA. I didn't know that there is a clear PVC pipe out there. Good info.

Good description about the procedure from dry to wet... Another good info.

However, as I addressed, it isn't for a scuba computer that has a depth sensor, so my question still remains.

Wow, at least I'm not far off the mark! So is it the size of the pan/tank or the pressure the lid can withstand that dictates how many ATM's of pressure it can withstand?
Is there a formula that you use to calculate how many ATM's it's equivelent too? Sorry for what might seem like dumb questions, but my interests are varied and I one day of dream of having a complete repair/service shop in my garage...

Thanks in advance guys!!

1 ATM = 33' = 14.7 psi.


This pressure pot is on my DIY list. I am thinking about using the scuba tank.