My sons home has a FHP GO036 unit in a closed loop system that was installed in 1986, there are some issues that I need to sort out with it. In the return line there is a 3" x 4ft long piece of pvc with a cap on the top and 2 pvc T's on the bottom, the return line comes in the bottom and then exits out 1 of the T's, the upper 3" x 4ft piece has a fitting in it that I do not recognize. I am thinking that this is some type of makeshift expansion tank ? and was wondering if anyone else had ever seen something like this. The whole configuration is very basic as there is no flowcenter, nor any P/T ports etc. I'll try to upload some pics. Thank you, Jerry
Any information you can offer. If it is some type of homebrew expansion tank perhaps that fitting was there to air it up ? It just doesn't look like any commercial product.
My money is on a home brewed air separator/expansion chamber to keep pressure in the system and air out of pumps. Eric
If you want us to figure out what it is, you need to show us the whole thing, top to bottom. Are there any similar fittings or valves at the very top of the column? But it appears to be an expansion chamber and a way to separate air from the water as previously stated. It definitely looks homemade. That small metal fitting on the side may have been a way to either add or bleed excess air out of the chamber, i.e. open it until water comes out then you know the water level is that high in the column with the remainder being air. With air in the upper part of the chamber, this effectively becomes an expansion tank which is able to accommodate small changes in water volume due to changes in temperature without having a significant effect on the system overall pressure.
Better pictures showing the entire set up would be needed. It sure does look like a “homeowner special” design. I would also agree on some sort of a air separator, or some attempt to purge air.
I hope to get out there in a week or two and will try to get a better picture. There are no other fittings and the one that is on there is nothing I'm familiar with. In the center of the fitting inside there is about an 1/8" square piece. You would have to get in there with a pair of needle nose pliers to see if it turns or not. The fitting is on an angle and there is no sign of any type of sealer or anything around it.
That fitting looks like a radiator bleed valve. They could be using it to check water level and or as a drain???
Yes, that is exactly what it is. https://www.plumbers-mate-sales.co.uk/radiator-bleed-valve-air-vent-14-brass---07000080-1777-p.asp And it looks like you need a radiator bleed key similar to this to operate the valve:
Good call ! That is what it is. Just goes to show you how easy it is to forget about things when the grey matter starts creeping in between your ears. I will have to see if I can find my key, I used to keep it on my key ring. The supply house used to give them out for free and the last time I used it was in the late 70's I'm attaching the layout of the system that I drew up last nite. Thanks again guys !
