One pipe radiator steam valve packed too tight salvageable?

nybigapple

I made a mistake when repacking a one pipe radiator steam valve that was leaking. I used way too much graphite packing, and overtightened. The valve is now unturnable even with the packing nut completely off. I tried removing as much packing as possible with a dental pick but it's just too small an opening at the root. Even for a dental pick. Is there anything that can be done to fix the valve or is the only option now a valve replacement? Was hoping there was an easy way to dissolve the packing but from what I'm reading nothing really removes graphite packing.

Valve is stuck in a partially open position and the radiator does heat up.

Fred

I can't imagine that too muck Grafite packing is the cause of this. In all probability the valve stem is jammed in the bonnet, probably misaligned thread. Take the bonnet off (with the boiler off) and see if you can unjam it. It might also be that the disc on the bottom of the stem is bent or jammed. It is repairable but you need to take the bonnet (large square nut below the packing nut) off to get to the inside of the valve. If you replace the entire valve, you will also have to replace the spud in the radiator as the valve and spud are a matched set. It will leak at the union nut if you don't.
With the valve part way open, the radiator will start to bang, especially when it's really cold out because water will be trapped in the radiator.

nybigapple

The reason I'm sure it's the packing is because the valve turned fine before I repacked it. It would just leak steam from the stem. So after I repacked it, no more steam leaking, but also can't turn it anymore.

I've seen all the work required to replace a valve. I'm not qualified to undergo that task. Are bonnets interchangeable? If I just buy another bonnet could I remove and replace?

Fred

Depending on the brand and age of the valve you may be able to buy a new valve and take the bonnet and stem off and put it on your old valve body. As far as I know they don't sell the bonnet alone but, if you take the stem to a plumbing shop and tell them what it is off of, they may be able to match it??? I suspect if you get that bonnet off, you will see your problem and be able to correct it. I know you think it is the packing. That might make it hard to turn but not impossible. I'm pretty sure the threads on the stem and the threads on the valve itself are jammed/misaligned.

nybigapple

Thanks for all the advice Fred. Was hoping for an easy fix. Since it's still working right now, at this point I'll leave it since it's winter, and anything going wrong would be a catastrophe. Oddly water hammer has not been a major issue. Upon first fixing the steam leak I did hear nonstop clanging in the heat pipe for about 5 minutes, where I assume certain parts were expanding for the first time in a while. But otherwise not a real issue since.

In the spring I'll see about removing the bonnet and getting it fixed/replaced.

Paul48

http://www.arpny.com/pdf/ValveSubAssemblies.pdf

Here's a big maybe....BIG.

nicholas bonham-carter

I would remove the packing nut and open the valve as far as possible. Hopefully, that upper movement of the stem will dislodge some of the packing string, enabling it to be pulled out of the annular recess. Close the valve, and get the packing nut started on the threads. Before tightening the packing nut completely, open the valve as far as possible.--NBC