Vacuum testing longer than 10 minutes?

So if I vacuum down to 15 or 20 I can see in 10 minutes it only drops the about 0.5 hard to tell exactly on non digital gauge. However today I pulled it to 20 and left it for an hour or so and it almost 5 dropped from 20 to 15, but in that first 10 minutes only dropped close to 0.5.

Is this to be expected? sorry if this is dumb my first underwater vehicle.

Hi @nfored,

I’d recommend reading through this thread. In particular:

This is above the pressure we’ve specified, and for a longer time period than we’ve recommended to test for, so isn’t something I can meaningfully comment on the results of (because it’s not the same test).

That said, I’d be a bit concerned about potentially damaging the cables by pulling enough air through them that they start to deform to allow air to flow through more freely. I don’t expect that would meaningfully impact the water-tightness of the vehicle under normal conditions, but it could cause future vacuum tests to fail (which makes them less usable as a safety check), and would likely increase the speed of a leak if a cable got a cut or gash in it while submerged.

Thank you, this was exactly what I had hopped but wanted to make sure as I have only tested water tight in a pool so basically zero pressure and noted 15 is the test point not higher.