Hello everyone,

A simple one really, I wondered how many of you have a dedicated pressure and vacuum testing manifold and your thoughts on how necessary they are?

I ask because a lot of literature I’ve been reading suggests that normal charging hoses aren’t rated for vacuum and may leak slightly under vacuum. Even product catalogues, in the blurb about the PVR manifolds, point this out. Also to consider is the fact that the gauges on charging manifolds aren’t accurate enough to show “smaller” leaks of either vacuum or OFN when vacuum/pressure testing (though I know correct practice is to use a dedicated vacuum gauge anyway, perhaps negating the need for a manifold gauge as well).

However, I was told that they aren’t necessary. And all Youtube vids that I’ve been looking at to educate myself on the vacuum and OFN testing stages use OFN and the vacuum pump in through the service hose of the normal charging manifold that was used for recovery. Nobody in reality (well, that I’ve seen in my limited experience) uses a charging manifold to recover, swaps over the manifolds to draw vacuum with a dedicated PVR manifold, then swaps back to the charging manifold to charge the system.

I see that most manufacturers of equipment provide 4-way charging manifolds such that a vacuum pump may be attached without swapping the service hose from recovery machine to vacuum pump as you do on 2 way manifolds. I would reason that if manufacturers of charging manifolds provide equipment such as 4-way charging manifolds, then it’s perfectly acceptable to use regular charging manifolds for the vacuum stage - otherwise there would be no market for them.

One may also use a vacuum rated hose from the manifold to the vacuum pump, but I would reason that this is redundant if the rest of the hoses are regular hoses and the manifold is a regular manifold. A chain is only as strong as it's weakest link and all that.

I’ve been debating all this with myself as I want to do things correctly but then it’s a waste of money if the reality is no one really uses them because in actual fact they just aren’t necessary. But I've been going around in circles with it and could do with some help. Does the wider collective have some opinions on this?

Do you use them? Are they a necessity? Or are they unnecessary?

Thanks for your time

Mark