Radiator steam trap replacement on Dunham-Bush Vari-Vac system

fastd

The coop where I live has a Dunham-Bush Vari-Vac low pressure steam heating system. The radiators (convectors) all have thermostatic traps containing discs and renewable seats. Don't know if the seats are thread in or press in. The system is 60 years old. From time to time the discs wear out, and they were all replaced a number of years ago. The management is talking about replacing some of the traps, or perhaps all of the traps. My question is: should the traps be replaced? It seems to me that replacing the discs and seats, which are the wear out items would be a better idea. Thoughts?

JUGHNE

You are fortunate that your Coop management has the awareness of steam trap needs.
Much has been written about changing all trap elements in one go before the heating season. Existing bad traps could destroy the new ones as they are installed.

If a good replacement element is available (not all elements are created equal...some vent air quicker than others...that is good) it seems wise to change only that. That may be what the board means when they talk about changing "traps".

To change the whole body requires the radiator spud to be removed which can sometimes be involved.

EBEBRATT-Ed

first get an approximate trap count for pricing. get the pipe size and model #s of the traps. contact "Tunstall Associates" or "Barnes & Jones" (you can google them) and ask them about repair/replacement. They can give you the options

gerry gill

Also check with Mepco who bought Dunham.

Sailah

I would recommend you call GS Dunham and speak to Mark. They are the experts in Vari Vac and also the rep for Mepco in NY. The vac requires a special type of element and only those sealed under vacuum will work properly.

Sailah

I guess i never answered your question either. Typically Dunham or Mepco traps do not have removable seats. The element is replaced only. If the seat is worn then full trap replacement is needed or you can use a B&J cage unit with new cover. The cage unit has a new seat built in. The cover is a one time buy.

You don't need new traps unless you want shiny or they are not repairable. Or the owner doesn't trust the contractor and wants new traps so they can visually tell.

fastd

Thanks for the replies. I've changed a couple of the discs in my own apartment about 10 - 15 years ago when the discs failed closed. The seats were fine then. The management decided to change all the traps (or discs - will find out when it gets done next week). Sounds like the B&J unit is the answer if the seat is worn. We'll see.