How do I replace a double-check/non-return valve?

[benny15]

I need to replace the double-check/non-return valve on the pipe that goes out to the back garden tap under the sink. I got the correct replacement part, but I am not sure actually how to remove the original non-return valve on the pipe. When I loosen the two nuts, it can slide a bit back and forth between the olives, but I'm not sure how I can remove the olives and even then how to get the valve off the pipe.

Do I have to take the whole pipe out or something? I am new to this sort of thing so there may be something obvious I'm missing.

(see attached pictures for clarity)

 

[Ben-gee]

You don’t need to remove the nuts or olives, just reuse them with the new one - make sure you fit it the corrrect way around, there is an arrow to show direction of flow.

To remove the old one you need to pull one of the pipes away from it - whichever one has least restrictions from elbows, tees, passing through holes etc.

If you take a spanner and rotate the body of the non return valve a few times this will free off any jointing compound that may have been used.

 

[benny15]

You don’t need to remove the nuts or olives, just reuse them with the new one - make sure you fit it the corrrect way around, there is an arrow to show direction of flow.

To remove the old one you need to pull one of the pipes away from it - whichever one has least restrictions from elbows, tees, passing through holes etc.

If you take a spanner and rotate the body of the non return valve a few times this will free off any jointing compound that may have been used.

Thanks so much for your reply. So I did try when I first loosened the nuts to pull the pipes apart to get it out but there wasn’t much give at all. The vertical pipe on the left is also connected to a pipe of the same length right above.


But maybe I wasn’t pulling hard enough when trying to move the pipe enough to make room to remove the valve for fear of breaking it.

Should I be trying with more force to pull the pipes apart to make room to remove the valve or if there’s not much give is there another way to do it?

 

[Ben-gee]

Yep, more force!

Only other thing is if there is some other compression fitting you could undo to free things up.

But I would just pull the pipe in the right out, knowing that in the unlikely event that I caused a problem - I would be able to fix it.