Hoffman 40 vs 1A ⅛" Connection Different?

SinglePipeSteamer

Last winter I replaced an old Hoffman 40 that had been sealed shut with paint with a new Hoffman 40. That room is the farthest from the boiler though, and always the coldest. So, I thought perhaps replacing the 40 with a 1A could help with that. I ordered the part, but the connection seems to be a bit larger and doesn't quite fit. I don't have an instrument to measure, but the tip of the 40 looks smaller, and almost like maybe there's a taper to it, the 1A looks larger without a taper, but I could be wrong about that. I am fairly certain the 1A is somehow larger though. I ordered both parts from Amazon, and I've included the descriptions below.

Hoffman 40 description from Amazon:
1/8" NPT angle connection

Hoffman 1A description from Amazon:
1/8" npt angle connection maximum operating pressure 1 1/2 psig (0.1 bar)

I guess my question is, are these indeed different size/shape connections, and what should I do? Is there a better vent I could use that would fit better?

JUGHNE

Can you post a picture of these 2 vents with them laying toe to toe?
The next pipe size up is 1/4" and a definite noticeable increase in size.

BobC

About 5 years ago I ordered a couple of Maid O mist air valves and they showed up with untapered threads (maybe BST?) and would not thread into the radiator. I ended up using a 1/8" NPT die on them to get the tapered thread I wanted. Thank God they were brass because it took a bit of oomph to run that die down the thread.

I'm sure a lot of these threaded stems come out of the same factory and occasionally things get mixed up in production.

Bob

ChrisJ

BobC said:

About 5 years ago I ordered a couple of Maid O mist air valves and they showed up with untapered threads (maybe BST?) and would not thread into the radiator. I ended up using a 1/8" NPT die on them to get the tapered thread I wanted. Thank God they were brass because it took a bit of oomph to run that die down the thread.

I'm sure a lot of these threaded stems come out of the same factory and occasionally things get mixed up in production.

Bob

There's 1/8" NPS which is national pipe straight.
A bit of oomph to run a die down some brass eh.......

BobC

Arthritic hands make everything harder, I ended up making a quick and dirty wood "holder to hold the vent so my hand wouldn't fall off holding that vent still.

Bob

ChrisJ

BobC said:

Arthritic hands make everything harder, I ended up making a quick and dirty wood "holder to hold the vent so my hand wouldn't fall off holding that vent still.

Bob

Believe me I understand. It can also be very frustrating and make simple things impossible.

Also, the very thin construction of the vent would make it difficult.

SinglePipeSteamer

I ended up ordering a Gorton No. 6 and that didn't fit either.  So, it seems the issue is more than likely with the radiator.  I've attached some photos as requested.  It's interesting to me that I pulled a Hoffman 40 from it and replaced it with a Hoffman 40, without issue, and that's the only thing that will fit.  The others just spin on the outside of the threads like they're too large for them.

Next question, how do I fix this?

nicholas bonham-carter

Run a tap into the radiator to clean up the threads?—NBC

JUGHNE

The tap is a good idea, just don't run in too far.

My old rebuilt eyes do not see much taper on the Gortons.
If one had an 1/8" pipe fitting to try them into that might tell something.

EBEBRATT-Ed

Yeah, agree with @JUGHNE

Try an 1/8" pipe nipple. The put a 1/8" pipe tap to the rad as @nicholas bonham-carter suggested and just go a little at a time.

No doubt this is a China problem.

Off track but I have a good story to tell about foreign stuff.

About 8 years ago we were working on the 26th floor of a 40 story high rise in Hartford, CT

They had the biggest plate and frame HX I ever saw and it was 25 years old and had started leaking slowly but gradually getting worse.

4 10" pipes fed this thing and no shut off valves near the HX.

So the decision was made to install a new HX adjacent to the old one. So the HX was ordered and they planned a shutdown to install some valves. This was going to take hours to drain and then weld in valves and tees start Friday night at 5pm and get it back on line on Sunday

So the material was ordered (not by me) but it landed at our shop and I went out to check EVERYTHING because a weekend shutdown with no open supply houses.

4 10" Cast Iron tees, 10" weld flanges 10" high performance butterfly valves (due to the high rise pressure) flexatallic metal gaskets and boxes of nuts and bolts plus all the tools ladders scaffolding welding machines etc etc

Everything checked out fine. The Crane HP butterfly lug valves (big $$$made in China) the flanges were from India, and the CI tees were Korea. But everything was there. Even the Crane valve needed different length bolts and they had sent the correct bolts I was surprised.

So we got started draining 4 of us on the job 2 welders 2 pipe fitters.

By Saturday we were tired but everything was moving ok until we started bolting valves on. The od of the metal Flexatallic gaskets wouldn't fit between the bolt pattern on the flanges just off enough so the bolts wouldn't thread into the valves.

So I took all the gaskets and ground down the od a little maybe 1/32" did it.......problem solved

Then everything went ok until Sunday when we were bolting the last valve in. The bolt holes in one of the flanges didn't line up, again just off enough so the bolt wouldnt go in. And of course this flange was already welded on (and we didn't have a replacement available anyhow)

So these were 3/4" dia bolts. Two bolts would not go in. Lucky for us we had some 5/8" threaded rod. Cut a couple of these and they fit through the holes and we put nuts on the outside of both flanges with valve in between and sandwiched the whole mess together

Looking at this after the fact, the bolt holes in the India weld flanges the holes were o the correct center line but the holes were drilled slightly undersized. When the gasket was put in the gasket pushed the bolts out "splayed" so the bolts werent straight hence grinding the gaskets.

The last vale?? who knows something was drilled wrong, but we had to get it back on line.

Sorry for the "foreign stuff rant"

ChrisJ

EBEBRATT-Ed said:

Yeah, agree with @JUGHNE Try an 1/8" pipe nipple. The put a 1/8" pipe tap to the rad as @nicholas bonham-carter suggested and just go a little at a time. No doubt this is a China problem. Off track but I have a good story to tell about foreign stuff. About 8 years ago we were working on the 26th floor of a 40 story high rise in Hartford, CT They had the biggest plate and frame HX I ever saw and it was 25 years old and had started leaking slowly but gradually getting worse. 4 10" pipes fed this thing and no shut off valves near the HX. So the decision was made to install a new HX adjacent to the old one. So the HX was ordered and they planned a shutdown to install some valves. This was going to take hours to drain and then weld in valves and tees start Friday night at 5pm and get it back on line on Sunday So the material was ordered (not by me) but it landed at our shop and I went out to check EVERYTHING because a weekend shutdown with no open supply houses. 4 10" Cast Iron tees, 10" weld flanges 10" high performance butterfly valves (due to the high rise pressure) flexatallic metal gaskets and boxes of nuts and bolts plus all the tools ladders scaffolding welding machines etc etc Everything checked out fine. The Crane HP butterfly lug valves (big $$$made in China) the flanges were from India, and the CI tees were Korea. But everything was there. Even the Crane valve needed different length bolts and they had sent the correct bolts I was surprised. So we got started draining 4 of us on the job 2 welders 2 pipe fitters. By Saturday we were tired but everything was moving ok until we started bolting valves on. The od of the metal Flexatallic gaskets wouldn't fit between the bolt pattern on the flanges just off enough so the bolts wouldn't thread into the valves. So I took all the gaskets and ground down the od a little maybe 1/32" did it.......problem solved Then everything went ok until Sunday when we were bolting the last valve in. The bolt holes in one of the flanges didn't line up, again just off enough so the bolt wouldnt go in. And of course this flange was already welded on (and we didn't have a replacement available anyhow) So these were 3/4" dia bolts. Two bolts would not go in. Lucky for us we had some 5/8" threaded rod. Cut a couple of these and they fit through the holes and we put nuts on the outside of both flanges with valve in between and sandwiched the whole mess together Looking at this after the fact, the bolt holes in the India weld flanges the holes were o the correct center line but the holes were drilled slightly undersized. When the gasket was put in the gasket pushed the bolts out "splayed" so the bolts werent straight hence grinding the gaskets. The last vale?? who knows something was drilled wrong, but we had to get it back on line. Sorry for the "foreign stuff rant"

After that rant it makes me wonder if you've ever worked on a 1970s-80s American made car.......

EBEBRATT-Ed

@ChrisJ
Gave up on cars years ago. I may check the oil and antifreeze if the car overheats or the oil idiot light comes on LOL.

Get real tired of foreign crap when it's not made right and very frustrating when all the parts are ordered and they were correct just correct junk. Maybe they make good cell phones, TVs, cars and other things across the pond but their pipe fittings arn't cutting it.

Screwing around with 10" stuff on a long weekend is no fun and when the stuff doesn't fit it's a problem

ChrisJ

@EBEBRATT-Ed so you're ok with locally made crap then?

SinglePipeSteamer

@JUGHNE there's just one Gorton in the photo.  From left to right, Hoffman 40, Hoffman 1A, and Gorton No. 6

Thanks everyone for all of the advice.  I'm going to attempt to chase the threads using the below supplies.  I have never done this before but just watched a YouTube video.  It doesn't seem too crazy a process but I am slightly worried that I might make the problem worse.

I also attached a picture of the threads in the radiator below that.  I've only had this house for a bit over a year.  It was built in 1924, though I believe the radiators are a bit newer than that.  The boiler is from 2017 so I expect to get many more years of service from this system.

EBEBRATT-Ed

That's the right tap, should do the job

ChrisJ

For cast iron and just cleaning threads you could use WD40 or even run it dry to be honest. Just go slow and take your time. Do not cross thread it going in and be careful taking it out.

JUGHNE

If you have 2 straight edges, perhaps 6" rulers, then put them 180 degrees apart perpendicular to the threads.
With the taper on the Hoffman's you will see that the straight edges are not parallel but will converge together at some point.

With the straight threads your rulers will stay parallel.

You could run a tap in and over tap a little and the Gorton's might start maybe 2 turns. If you then force it the brass may snap off inside the rad.

I would call the supplier and insist on the right parts with the correct taper......just me, I can become a crotchety old PIA with time to sit on speaker phone and become belligerent.

I agree with Ed, one gets tired of getting junk and having to put up with it.

So there, venting done for now!

ChrisJ

I agree with Ed that junk sucks.  I just got an 84" length of 1 1/4 pipe threader by a local place a while ago and just found out the threads don't work.  I suspect they're not deep enough but I'm not sure yet.

I'm tired of junk but in my experience it has little to nothing to do with where it comes from.  

EBEBRATT-Ed

Having a piece of pipe threaded by an idiot at a supply house is one thing. That can happen anywhere. Fittings from outside the USA......not all of them but the vast majority from Asia are of inferior quality. I don't like junk no mater where it comes from, there's plenty of USA junk as well, but we are talking about pipe fittings specifically. We don't go to a supply house expecting to walk out with junk.

SinglePipeSteamer

I'm happy to report the valve is installed.  I started by first confirming the threads are good on the two new valves.  I ran them through a die with no friction at all.  Next, I chased the threads with a tap.  It was scary.  It felt crunchy while I turned it, and I wasn't certain it was even going it at first, but eventually I hit the end.  Then, I backed out it and there was a ton of black crud in it.  I tried again installing the Gorton No. 6 and this time it went it smoothly and I had no issues tightening it.

I fired up the boiler and ran around with an IR thermometer.  It's now the hottest radiator in my house, in the room that's consistently the coldest room in my house.

Thanks for all of your assistance.  You all have been wonderful.