60’s baseboard boiler heat valve question

Kinger

Hi, Hope someone know what these are..
I have boiler heat with baseboard radiators. On the end there is a Sarco 1/2" valve. 3/4” nut with a slotted center for a screwdriver. Does anyone know if this is for bleeding or for controlling flow?
Are used PB blaster and a heat gun to free them up. The slotted part in the middle does not tighten up. It just keeps turning. I will attach some pictures. Maybe I’ll get some help.



Thanks in advance..

EdTheHeaterMan

That is similar to a ball valve. The slot in your photo indicated that it is open. The nut you removed is a packing gland adjustment. Too tight and you can't operate the valve. too loose and the valve will leak. Since you have removed it, you may be able to add some packing material. I have used teflon tape in a pinch, you can also use lamp wick. But you can also purchase graphite rope type gland packing. Or you could get this from your local Home Depot. https://www.homedepot.com/p/DANCO-3-32-in-x-36-in-Valve-Packing-80794/203193512

Kinger

That’s what i was thinking but will it bleed air out when you loosen the nut as well, or just control flow?
Thx

EdTheHeaterMan

Not a bleeder. Just a valve

Kinger

Thank you very much.

hot_rod

Seems like a lot of brass for a simple shut off, perhaps it has a balance function incorporated?

EBEBRATT-Ed

Looks like a balance valve probably not a tight shut off valve, reason being it turns and turns with no stop.