Overpressure Relief valve source for DIY Canister ?

[zebu14]

Basically I would say the only main reason to have a relief valve is because the light floods at depth.. that will build pressure as you surface or open it,,,
How often do these canisters flood?
If the latches hold, it should be no big deal, might wreck the oring, and and serious pressure probably will extrude the oring out of the gap,
Personally it's another leak point

I am not sure to follow/understand your explanation.
Why do the canister should flood at depth ? They are meant to be pressure proof aren't they ?

In my opinion, the OP valve role was to evacuate gas in case of a battery thermal runaway during use or charge.

Maybe I am wrong, but if you have more explanations about "the light floods at depth", they are welcome

Thank you

 

[Gone for diving]

You are right they should not flood at depth,,,, but many times things do flood with improper assembly etc,
Like DPV'S , lights, cameras, etc,

So if the switch boot, cord gland seal, lid oring leaks, at 100 ft, water comes in and pressurize the air you could have 43ish psi in the can at the surface,,,, which could have a surprising affect when opening, (assuming the air can't get out.. . Like the canister was mounted upside down, and the air didn't leak out..)
This whole scenario is quite unlikely to trap air, so you will have a flooded canister full of water and no air in side,
So basically zero pressure as the lid is opened,

The pressure that you might get with normal batteries, is very low and not a problem,,, unless it catches fire inside,, then you have other problems,,,,

So my conclusion is to forget about it,
not needed, all the canisters I have made, never had one, and work fine,,,,

 

[tbone1004]

You are right they should not flood at depth,,,, but many times things do flood with improper assembly etc,
Like DPV'S , lights, cameras, etc,

So if the switch boot, cord gland seal, lid oring leaks, at 100 ft, water comes in and pressurize the air you could have 43ish psi in the can at the surface,,,, which could have a surprising affect when opening, (assuming the air can't get out.. . Like the canister was mounted upside down, and the air didn't leak out..)
This whole scenario is quite unlikely to trap air, so you will have a flooded canister full of water and no air in side,
So basically zero pressure as the lid is opened,

The pressure that you might get with normal batteries, is very low and not a problem,,, unless it catches fire inside,, then you have other problems,,,,

So my conclusion is to forget about it,
not needed, all the canisters I have made, never had one, and work fine,,,,

only sort of, if you put a boot switch in there it will blow if there is a battery fire and that's what you really need the OPV for