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Mini split AC union
- Thread starter jjrbus
- Start date
Ohmthis
Well-known member
I put the “vacuum” (I’m assuming micron gauge) on one valve of a recovery tank. I connect my hose from a vacuum pump to the other valve. Pull a vacuum, and watch the gauge. This set up tests the hoses, micron gauge, and pump.
Thanks it appears the 1/2" acme cap on my vacuum pump is not sealing.I put the “vacuum” (I’m assuming micron gauge) on one valve of a recovery tank. I connect my hose from a vacuum pump to the other valve. Pull a vacuum, and watch the gauge. This set up tests the hoses, micron gauge, and pump.
danski0224
Well-known member
Do not trust the valve on the vacuum pump.
Firebrick43
Well-known member
Most residential units use 1/4 SAE flared fittings and some mini splits now use 5/16 SAEI am in need of a 1/4 inch flare union to test my CPS vacuum gauge and hose but not sure if the unions sold at the big box stores are the same as refrigerant unions. Are they the same or different??
Are you sure its acme? Most pumps are SAE flared, at least every single one I have used, mostly JB.Thanks it appears the 1/2" acme cap on my vacuum pump is not sealing.
Last edited:
fitter30
Well-known member
All refrigeration flares are at a 45° angle. Refrigeration supply/ amazon have 1/4" male flare unions. Vacuum pump oil is very important that for the best vacuum oil needs to be changed everytime especially if pump sit for a week or more not being used. Moisture is the problem which relates to vapor pressure. Just because I the oil looks clean doesn't mean it hasn't picked up moisture.