Connecting Air Vent to New Cast Iron Radiator

Moderndandy

Hello,

I am trying to replace a steam radiator in my home and I am not certain how to open the connector to connect my Hoffman Air Vent. It's a 1/8 tapping. From videos I have seen online, it seems like usually there is a plug that you would remove. However, this one doesn't seem to have that. The manufacturer has offered no help so I was hoping someone here might have worked with this before. Currently there is no hole there.

Thanks for any Help. Picture below

KC_Jones

That's not the correct location for an air vent on a steam radiator. There should be a bung about 2/3 of the way down one of the tubes. It most likely would need to be drilled and tapped for the 1/8" NPT vent threads.

Take a picture a little further back so we can see.

FYI installing it where you are showing can cause it to short circuit and not completely fill when needed.

ethicalpaul

The supply hole pictured seems to be at the top of the radiator. Is this one pipe, or two? Is there another set of supply ports at the bottom?

Moderndandy

Thanks Everyone for your help and advice. Attached is the picture from a bit further back. There is in fact another possible connection place further down as you will see.

The radiator has multiple options for configuration. Two 1"openings on top and two 1 and 1/4 openings. The radiator has plugs for them so the two on top will be plugged. One on the bottom will be used for connection and the other plugged.

BobC

Drill and tap that third tube for a 1/8 -27 NPT, start with a pilot hole in the center of that boss and work your way up to the suggested tap drill size. You may think that is too low but it will work fine. You can buy the tap and drill from a good hardware store or Amazon, you will also need a tap wrench.

https://www.amazon.com/Century-Drill-Tool-93201-Combo/dp/B0797JWQ1R/ref=sr_1_3?keywords=1/8-27+tap&qid=1567697623&s=gateway&sr=8-3

Use a fairly slow air vent so the radiator fills with steam.

Bob

Moderndandy

OK Got it! Thank You to everyone for helping me out

KC_Jones

Air vent location circled in red.

Moderndandy

Thanks!!

Grallert

Don't take this the wrong way but are we sure this is a steam system. Is so you'll have to drill and tap one of those lower vent boss'

JUGHNE

Those aren't by chance a soft plug to keep paint out of the rad that you must remove all of them and screw a metal plug in the unused ones?
The drill will tell you right away.
If cork or plastic hopefully they don't fall inside.
Corkscrew for a tool comes to mind. FWIW

ethicalpaul

Drilling may not be necessary. Is that a plug screwed in there? Hard to see.

Moderndandy

Yes ethicalpaul, It looks like it could be.
Actually that was what I was expecting when I purchased. Any recommendation for the right tool to open it?

Steamhead

Allen wrench. Not sure what size, but they come in sets. Get a good one that won't strip out.

JUGHNE

I see it now, IIWM, I would clean the inside corners of the Allen plug and also the outside threads where it is screwed in with an ice pick, make sure of a tight fit, taps on the tool to bury it and maybe loosen the plug. and go for it.

Moderndandy

Update, It worked. They were plugs and after cleaning them out and getting a good fit with the allen wrench, they came out pretty easily. Problem Solved. Thanks All

mattmia2

I find the socket drive type allen bits are easier to control and press in to keep them from camming out. even better if you can drive it with a t-handle