Radiator vents

Mize

I want to replace all of the old Hoffman 500 radiator vents, but the ones available appear to have a different size thread.  I have a few, but have been waiting until they fail.  I need at least 2 or 3, but would buy more if available. Also, if there is an equivalent, information about that would be appreciated.  Thanks. 

nicholas bonham-carter

radiator vents

what leads you to believe the vents you have need replacement?

in a 1-pipe system, it is the main,[not radiator] vents which do most of the air evacuation. if you are having balance problems, i suggest you replace/increase the main vents on the dry returns. high pressure can also interfere with the venting.

if you could post some pictures of the vents you have, we could better advise you.--nbc

Mize

radiator vents

The ones we have are calcified and several have failed.  The leather washers have probably dried out.  I'd like to replace them all, rather than wait for them to fail; but can't find the original size Hoffman 500 and don't want to replace the bushing.  Any suggestions?

Steamhead

Is this

a steam or hot-water system? 

Mize

Radiator vents

This is a hot water system about 25 years old. 

Steamhead

I'd bet

that system had air problems and someone installed these as a "solution". They have their place, but not as a band-aid. A proper air separator installed near the boiler together with the circulator "pumping away" will solve the problem.



The usual thread for vents is 1/8" pipe thread, which has an external diameter of 1/4" or so. Is that what you have?

Mize

Original vs new size- Please help

The original vent has a 3/8" diameter and the new ones are 1/4".  Can anyone suggest a substitute or does anyone know of any original size Hoffman 500 vents laying around somewhere?

Rod

HW Radiator vents.

Hi- You mention "the new ones" what make and model are the new ones? I believe the Hoffman 500 is now obsolete and has been replaced by a Hoffman 508.



Pipe size is determined by the inside diameter of the pipe. A 1/8 inch pipe would have an inside diameter of 1/8 of an inch and an outside diameter of close to 3/8 inch. As pipe thread, it also has a slight taper.

- Rod

Steamhead

Since the new ones are smaller

you can install suitable bushings in the existing holes, and screw the vents into the bushings.

Mize

Clarification regarding vents

I want to replace all of the old Hoffman 500 radiator vents, but the ones on the system are not readily available.  This is a hot water system about 25 years old. The ones on the system are probably all calcified and several have failed.  The leather washers have probably dried out also.  I'd like to replace them all, rather than wait for them to fail; but I can't find any of the original size Hoffman 500.  The new ones- #508 have a larger external diameter and I don't want to replace all of the bushings. 

I have a couple of the #500s left and have been waiting until each one fails before replacing them.  I need at least 2 or 3 to replace the rest, but would like to buy more if available. 

I’d like to know if there is an equivalent from another source and any information about that would really be appreciated.  Does anyone know of any original size Hoffman 500 vents laying around somewhere or have any other suggestions?Sorry if my original post wasn’t informative enough and thanks in advance for any help that you can provide.

Charlie from wmass

Mize what leads you to believe

That a standard coin vent would not be fine for this application? I prefer to only use manual vents on hot water radiators. As stated the 500's were bandaid solutions to permanent problems.