I topped off the R-22 in my ancient home A/C yesterday, and when putting it all back together, I dropped the cap for the service valve. This is the thing with about a 3/4" hex and a cylindrical dome above it, that seals the valve stem of the service valve. I thought the cap was steel, and searched the whole area with a strong magnet, then assuming maybe it was brass I searched some more with my hands, but still have not found the darn thing! I'd swear I saw where it dropped, too, but just a minute later it was not there.
Anybody know where I could get one of these? This is for a 44 year-old Bryant condensing unit. I looked on eBay, but nothing came up.
They are inexpensive usually brass and readily available from a refrigeration supply shop. The service port is typically a male flare taper and thread, and the service port cap usually has a gasket in it that seals against the end of the service port. Usually they are 1/4 inch flare, but some equipment may have 3/8 flare. I think one of my HVAC units has one odd size cap. On service equipment such as vacuum pumps and evacuation pumps you can find them in brass or plastic used to keep airborne dust out of the equipment when not in use. Steel is unlikely as it would react with the brass body of the service port.
If you are in the USA I'd be glad to send you one. I have atleast a half dozen brand new 1/4 inch flare caps in my box of HVAC service stuff. More than likely you can go to a local HVAC supplier and get one on Monday quicker than I could mail one to you.
Many HVAC techs reuse them, but because of the gasket I treat them as a replaceable service item.
Places like "Supply House" ship nationwide if you don't have a local refrigeration supplier, and you would prefer to purchase them.
I think it is unlikely that a big box supplier like Home Depot or Lowes would have a service port cap, but a smaller well stocked local hardware store might. The chance is slim, but possible.
What he's describing isn't what you're describing. Based on him saying that it covers the stem on the valve, I'd be looking for the lighter-colored part of this:
Of course if the valve packing is good and the bonnet nut is tight, the cover is superfluous. I serviced one machine that had 60 valves and the stems on every one of them leaked. The previous tech had simply applied a bunch of teflon tape & dope to the caps to keep them from leaking rather than about 5 minutes to disassemble, repack and reassemble. Somewhere out there is the worst mechanic in the world...