I'm researching parts for a heating manifold and am confused about what size or type of fitting is correct. More specifically, what the standard size of the fitting actually is.
The manifold is a Rifeng / Vevo make, which I think is also sold under a bunch of other name brands like Bluefin. The fitting in question is for each of the loop ports - its threaded and seals with an O-ring. Example:
The example parts that I can find are labelled "EK20". Here's an example of a '1/2" PEX to EK20 Loop Fitting' .
But I can't find any info on what "EK20" really means. I actually was able to screw on a US garden hose fitting... it went on "OK", not very smooth (but that's not uncommon with GHT). I didn't try it with any pressure or anything like that so I don't really know if it was a match [see below].
With fitting types like NPT for instance, you know exactly what will work with what. That's why I'm hoping to find some better info on whatever EK20 means, especially if brand names disappear over time.
I did come across a forum post claiming it was a "Eurokronus" fitting, but that search term seems like a dead end.
Update - I did a little test using a few garden hose caps. While they do screw on and feel like they tighten, they definitely do not seal well. I tried one under a little air pressure and it would leak. Possibly the threads are subtly different so that they aren't really tightening on rubber washer.
But also I noticed that another EK20 fitting I have has an O-ring with a much smaller diameter so that it fits within the male portion against a beveled edge; whereas a garden hose rubber washer seats on the outer surface of the male part and maybe cannot provide a good enough seal.
In any case, GHT is evidently not the same as EK20, at least in all the details.