Now that the new boiler is in and fired & blown down a few times, all 4 blowdown valves will not seat. I'm guessing that chips from the drilling have damaged the seats. I can easily imagine a tool that would dress these seats - a smooth stem that runs just inside the threads of the body, for proper squareness between the threads and the seat, and some kind of cutter on the end. Alternatively, perhaps the alignment could be done by extending a pilot beyond the cutter to locate the tool using the lower bore.

Is this a commercial product that I could buy? If not, has anyone made one who has drawings available?

Thanks,

Kelly

Kelly
Remove the valve stem from the valve and inspect it. You may have to turn a new end on the stem first. I do this on my 16 inch lathe without removing the handle. See attached tool.
Over the years I’ve done it on many valves. If the seat need to be returned a dummy valve steam need to be made with a pilot hole down through it, it should be made from 01 or D2 steel and hardened as the hole is the size of the bit to put on a new seat. I like a square end of a long end mill, for the boiler blows. Fuel valves need a tapered seat.
Rolly

I had to find the drawing and convert it to a jpeg.
Pilot drilling sleeve and D bit. Made from 01 or D2 steel.
For re seating valve seat.
Rolly

Through the years, I also have had problems with the blow down valves' stem faces pitting from rust and then leaking. To fix the problem, I have been making new valve stems out of stainless steel. No more pitting occurs on the new stainless valve stem faces. For re-seating the new stem into the bronze valve bodies, I take the new stainless stem and I twist it back and forth in its bronze valve body's seat. I have found that 99 percent of the time, it is the valve stems' fault for leaking. If you are ever on the road and a blow down valve starts to leak and it cannot be turned off, temporarily switch the valve stem out with another one on the car, one that is usually left in the "on position". A fuel shut off valve stem at the fuel tank would be an example of one to switch it out with. On a tour at Steamboat Springs, CO, my boiler's hand bypass would not shut off. That time I found a foreign piece of something that had found its way to the seat and fowled it. I removed the bypass stem and the piece was flushed out. It was just like new again.