Hope this is useful information, might all ready be in another thread some place on forum. Been trying to locate both a hot water tank adapter kit (which is not easy if you live in Canada) as well been trying to find the correct half coupling in stainless steel for a good price verus using a copper half coupling in NPT thread type.
From my understanding, the thread on a hot water tank heater is 1" NPS (straight thread and not NPT or taper). At first could not find anything at Mcmaster but eventually stumbled upon what I require.
Tried copying the link, but for some reason that will not work with how McMaster online catlalog works, so here is the only way I can show how to get there
1.) Go to http://www.mcmaster.com
2.) Search for this term, "Low-Pressure Stainless Steel Threaded Pipe Fittings ".
3.) You will see the following note :
"Type 316 stainless steel has a higher nickel content along with the addition of molybdenum to give it better resistance to corrosion than Type 304.
Connections: NPT, except locknuts which are NPSL (National Pipe Straight Locknut) and Type 316 stainless steel hex-socket plugs which are NPTF (Dryseal). Note: NPSL and NPTF threads are compatible with NPT threads."
Which from my understanding means this type of locknut will work with the threads on a hot water heater, as well the price for 316 SS is $5.76 and 304 SS is $5.22 which seems to be pretty good. As the only other place I found to get this from online is http://www.bargainfittings.com/index.ph ... duct_id=57
Going to order a couple locknuts that will be tig welded to SS keg along with buying couple normal 1" NPT half couplings for eventual drainage hose hook up for the keg.
Hopefully this helps someone else, as well hopefully the gurus can confirm this is correct. And like I said this might all ready be located on here some place else, if it is please delete this post.