Copper coupling questions

[lmei007]

There are different description about the coupling like the following. What are the differences?

1. 1" copper coupling with stop;
2. 1" copper C x C coupling with stop;
3. 1" copper pressure C x C coupling with stop;
4. 1" copper ring coupling;


Which one I should use for my hot water heating piping?

why the coupling without stop is more expensive than with stop?

 

[hj]

quote; why the coupling without stop is more expensive than with stop?

They don't make or sell as many of them, so the economies of scale are different. 1, 2, and3 all describe the same fitting. I am not sure what you mean by a "ring coupling" because I have never heard the term.

 

[Sponsor]

 

[lmei007]

Here is an example of the ring coupling.

 

[Terry]

In our book, a ring coupling is the same as one with stops.
A coupling is a coupling is a coupling, as long as it's not a "repair" coupling. (coupling less stops)

 

[hj]

In that case all FOUR of your types are the same thing, just different nomenclature.

 

[Reach4]

How do they distinguish the fittings that are pre-soldered vs those that do not come with solder?

 

[Jadnashua]

Buying a fitting that is pre-soldered is still no guarantee it will give you a better joint...you still need to clean both the inside of the fitting and the outside of the pipe well, and flux (I think) is still required. I see so few of those in the stores, I do not remember if they have any special designation. I do, though, like to use tinning flux. YOu can see when it starts to melt and know when to add solder, which, I think, aids the DIY'er and may help from overheating the joint and burning the flux out.