A/C Manifold Gauge Set selection help

[alumarine]

Hi there, I need to purchase an A/C Manifold Gauge Set and hoping an A/C pro can help out with the selection.

I've used the kind with Valves on the manifold but no Valves on the Quick couplings and they seem to work fine for me.

I've seen sets that have Valves on the Quick Couplings.

I have two questions.

1) What's the advantage to having the Valves on the Quick Couplings?

2) Why do the Valves on the Quick Couplings work opposite to the Valves on the Manifold?
At least I think they do. It seems that the Valve's on the Quick Couplings close when turned CCW and open when turned CW?

thanks

 

[JRZEE2000TR4LTD]

Hi there, I need to purchase an A/C Manifold Gauge Set and hoping an A/C pro can help out with the selection.

I've used the kind with Valves on the manifold but no Valves on the Quick couplings and they seem to work fine for me.

I've seen sets that have Valves on the Quick Couplings.

I have two questions.

1) What's the advantage to having the Valves on the Quick Couplings?

2) Why do the Valves on the Quick Couplings work opposite to the Valves on the Manifold?
At least I think they do. It seems that the Valve's on the Quick Couplings close when turned CCW and open when turned CW?

thanks

Just bought a set because I was tired of messing with no valve kind. On my cheap set, as soon as I would push them on sometimes if you didn't get them on right away, refrigerant would leak out. You are pushing against the pressure of the system to get the coupling on the fitting. With a valved coupling, you just snap the coupling on the fitting without depressing the "shraeder" valve Not allowing any refrigerant flow until you're ready. Then you turn the knob and flow starts.

Also its opposite because when you turn the manifold set knobs inward you are pushing a valve INTO a seat thus stopping flow, The knobs on the couplers are pushing the valve OFF of a seat, thus allowing flow. Hope that makes sense.


There are other things to be aware of with manifold sets and such.

1.) When reading pressure make sure the manifold set valves are closed.
2.) Watch for any hose to nipple connections where a schraeder depressor is needed. Some manifold sets have schraeder valves in the nipples of the ports where the hoses are which means the hose needs a depressor (an appropriate sized depressor at that) to allow flow. Seems obvious but I swear this was one of my number one service calls on the AC machines.

I could write a few more but some stuff you just have to make the mistake and learn from it.

 

[alumarine]

Thanks for the very prompt reply!
You explained it perfectly.
It makes sense to me now.
They're not valves as much as they are Shraeder Valve depressor's.

Thank You!

 

[VincentGsrq]

I have a Mastercool 89660 set that I was given free and they worked OK but it certainly does give a puff when uncoupling and you need to bleed out the service line.