Expansion tank replacement dilemma

[varmint]

I have a solar heating system for my shop I put together with two large Novan flat black chrome panels, a circulator pump and a NASCAR oil radiator with a computer cooling fan. I forget the brand of the solar controller.
The system uses Brayco 888 oil, which was what Novan systems (circa 1982) used. The expansion tank, which has a Hydrin membrane, has failed, and I simply cannot find a new tank with a membrane that is compatible with oil! Everything I can find uses Butyl rubber. Not good. I would appreciate any suggestions/help! I would like to continue to use the oil, and not flush, clean and replace the fluid with glycol or something else. Thanks, John... new member here.

[J.P.M.]

1.) Accumulators inc., (713) 465-0202 may have some info. When working, I'd call them infrequently (if I had a weird application involving goofy fluids), but it's been a while. They may be out of business.

2.) I suspect even if you find someone with the right materials, it'll be cost prohibitive to have a tank made, much less pressure tested, ASME inspected and warranted.

3.) From what I could find rooting around on the net, cleaning a system of old Brayco 888 is a pretty tough task due to the difficulty of ensuring all the Brayco oil is flushed, and also, changing fluids is not a good idea when using that oil due to what it's likely done to system materials.

4.) Hydrin is made (sold?) by Zeon (502) 775-7777. They may have some information.

5.) Did you post at a forum called the Garage Journal back in 08/10/2008? Similar post and application.

My guess is you can get a new system for less money and hassle than fooling around looking for materials and/or fluids that may not be available any more.

Good Luck.

[varmint]

Thanks. I contacted Castrol, the makers of Brayco, and learned the replacement for 888 is 889. Whether it is compatible with Butyl rubber is under study. There is a Hydrin tank sold in Belgium, but it isn’t shipped outside the country. Bummer.