In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Has anyone seen threads like this on old steam systems? I've been in the trade for 45 years and this is new to me. Look at the pic - it is a shallow fine thread like on a lav pop-up tail piece, but is tapered. I have laid a standard thread next to it for reference. Regular 1" and 1-1/4" radiator valves are screwed onto these threads with little damage. I needed to extended the riser due to a higher floor and planned on using an extension piece. You all know what kind of job I got into replacing the riser. I was able to screw the old valve onto a regular pipe thread. Why the fine thread? The other end of the riser has a standard thread. This one pipe system is probably approaching a century of service.