# Threaded vs Union Threaded connection



## dogwood (Dec 10, 2009)

I am getting a Watts Series 1156F feed water pressure regulator, http://s3.pexsupply.com/manuals/1249544554380/Watts-BronzePressureReg-Specifications.pdf. I need to choose between a "threaded inlet connection" or a "union threaded inlet connection" when ordering. Does anyone know what the difference would be between the two? Can't seem to find the answer on the internet. Thanks.

Mike


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## mbovee1 (Dec 11, 2009)

The threaded inlet will be just as pictured on the first page of your PDF link. I think that's the 1156F. See the threads? Your inlet pipe will need to have threads to connect (or you can solder on a male adapter if its copper pipe). This means that you will have to twist the regulator onto the pipe, which means to say you will have to assemble this as you assemble the adjacent plumbing. You won't be able to add this to an existing system because you can't twist each adjacent pipe to install the regulator.

The S1156F, soldered union style, means that you will solder a fitting onto your inlet pipe, then that fitting will turn to tighten the regulator into place. You will be able to install or remove the regulator for service or replacement without having to disassemble or remove any adjacent plumbing. 

The T1156F also has a union connection like the previous one, but this union threads onto the existing pipe as well as the regulator. See the union fitting to the left in this picture, http://www.pexsupply.com/Watts-0386450-S1156F-1-2-Union-Solder-Iron-Pressure-Regulator-3572000-p      This would be used if want the ability to remove/ replace and already have a threaded connection on the inlet pipe (or a threaded ball valve or check valve or BFP or something adjacent).

If you have a galvanized, iron, or threaded copper water inlet pipe already, I would use the last one so that you can easily install, and replace or repair as needed. If you have a copper pipe that's not threaded, I would use the second one by soldering on the included union fitting. Unless the other two are much more in price, I would not buy the first, as I am always maintenance minded. Regulators do go bad, especially if you have particularly high or low incoming water pressure already. If you have a Lowe's or Home Depot nearby, check their price, too. The one's around me stock some of these, and you won't have to pay for shipping. And you can go look at them and see the differences.


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## dogwood (Dec 11, 2009)

Thanks Vondera for going through all the trouble of looking at the various models, figuring this out and explaining it. This is new piping, I will be using copper pipe on the feed supply line, so will get second alternative, the S1156F with the included fitting, and solder it on. Should be easy to service then just as you say. Thanks again. I'll check out Lowes and home Depot too. 

Mike


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## mbovee1 (Dec 11, 2009)

No problem. Sounds like you are at about the same point I am in setting up my system. Unions are expensive by themselves, but I've found that many in line devices such as regulators, check valves, etc. are available with union connections at one end. I like to use them so that I can disassemble the system if I need to service. Keep in mind that when you have a group of in line devices, you can use one union ended device and then some threaded nipples or threaded valves, whatever is needed, in between and you will be able to minimize the need for copper adapters and still be able to service all of the components easily. Good luck.


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## dogwood (Dec 11, 2009)

Good thinking. Thanks again.

Mike


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## Eric G (Dec 12, 2009)

Hey mike glad too hear you are getting closer. I have been building a masonary chimney last couple days--got it too the roofline now I switchover too brick. Theres only one problem-its 20 here LOL. Wont be cutting the roof till monday I suspect-supposed to be above freezing (JOY!). Oh yah I saw the extra parts were extra cutting jaws--Thats great! I dont know if you have started the screwed pipe or not but spend a little extra and put a few unions in. If you develop a leak on a thread and its a bunch of joints away from a union-guess what? --It all comes apart to get too the leak. Keep that in mind. There is a new pipe dope on the market -its called "Super Dope" -yup thats right lOl! I'll tell you its the best stuff I have used yet. Now its all we use. Oh yah and something I wanted to mention. If down the road the prv ever seems like its not holding the correct pressure. Well purge of the extra and watch it. If it climbs very slowly chances are there is a peice of scale trapped in the diaphram. Sometimes opening the lever for a second or two free's it. (full line pressure.) Sometimes you can take them apart and clean them and they function properly again. Sometimes there just JUNK! through away. PIPE ON!


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## dogwood (Dec 12, 2009)

Thanks Eric. I always appreciate practical advice. I'll save it for future reference..

Mike


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