Hello,

I am aware of a few applications for couplers:

1. One where you need to clamp it. This type will have barbs on the end of the fitting and you just need to insert the fitting into the pipe and clamp each end.

2. One where it is a compression type that you just have to get the pipe inside until tight; this type will just look like the only option is to insert the pipe inside of the fitting and the pipe will stay.

3. One were you put the pipe and into the fitting and tighten a piece over top of the pipe. This type will have a loose part on the ends that you can twist once the pipe is on.

Let me know if you need any pics. Where did you buy the fitting and what was the advice given to you from the store?

bOb