pump down with king valves

[r247yan]

hope some one can help me out... ive been doing ac work for a few years and sometimes just pump the froen back into the compressor, then recover back at the shop... ( they all have the regular valves you can open and clpose with service wrench ) i had one the other day, the unit was old and had those king valves in it,, what is the proper way of pumping froen back into compressor with those..

trying to get an idea.. i know you have to open them to see pressures and all but i am new at king valves

[Swampfox]

Front seat the liquid line valve, pump down, then front seat the suction line valve, by front seating I mean all the way clockwise.

[chevytruck22]

King valves are basically the same. They have three positions, back-seated, front-seated, and the "cracked" positions. This is how you tell the difference:
back-seated: allows the refrigerant to flow through the valve, it's normal operating position, and the guage port is closed.(valve shaft all the way out)
"cracked": or mid-seated. allows you to read the operating pressures on guages, usually only a couple of turns. (tighten valve stem)
front-seated: allows no flow through the valve, but your guage port is opened. (valve stem screwed all the way in)

So basically if you are trying to pump down the A/C into the condenser, you would hook up guages, front-seat your liquid line king vavle, pump the unit down, then front-seat your suction line valve.