Home » HOW COMPRESSION FITTINGS WORK – Joining Copper Pipes and MLCP Blansol Plumbing

COMPRESSION FITTINGS. How Plumbing fittings work. Compression fitting copper pipe. Plumber.
How compression fittings work, or how to join copper pipes with compression fittings.
I wanted to show a video on how to join copper pipes with compression fittings. I’ve seen them done incorrectly quite a lot. Often see it like that with PTFE all over the thread. And I wanted to show you the right way on how to do it. You see there, I’ve just cut that part so you can see inside there. So I’m going to show you how to connect it the correct way. I’m going to show you a few products that I use instead of PTFE tape. And I’m also going to do some MLCP compression, so I’m going to show you that as well. That’s not really what this video is about. It’s really about the copper side of it. But yeah, let’s have a look.
So first of all, I want to start off with how not to do it. So when you put PTFE tape on and you put it on the thread, like that. So if we take our nut off on there. What it does is, if you put too much PTFE tape on here, it’s difficult to tighten it up. So that is the wrong way to do it.
To show you the correct way to do it. First of all, I’m going to show you the fitting. And if you have a look inside that fitting, it’s got a tapered edge in there. And then if we have a look with a fitting, you also have an olive like that. And if you look on the olive, the olive also has a tapered part of it. If you see, they join together like that. And then we have the nut. And it’s a little bit difficult to see, but in that nut, it’s also got a tapered edge. And then that goes on to that. And that’s where your pipe would go in.
Got some copper pipe here. It’s been cut with pipe cutters. In the real world, you would deburr the inside of the pipe. And then your copper pipe goes inside where the nut is. When you’re putting it in, you need to make sure that you put it in square, if that makes sense. So you don’t want to try and push it in at an angle. And you want to make sure that this is fully in. See there? It’s fully in. And then, I’ll take this apart. I’ll show you what it’s like inside then. You got your olive there. What I’m going to do, I’ll nip this up now with a spanner.
This is a really basic plumbing video, but it’s amazing how many people do very easy and very basic stuff wrong. So for trainees, we’ve got group on Facebook for trainees. So I thought I’d do a few of these videos to show the basics. And I’m going to do other things as well, like lifting floor boards up and things like that because a lot of people don’t seem to know this type of stuff. So I’m going to tighten this nut on here now. We don’t need to go mad with this. Once you feel it’s a little bit tight, it just needs a quarter of a turn, and then that’s tight. So what I’ve done there, I’ve made sure the pipe is fully pushed in. There’s no PTFE or anything like that on there at the moment. I’m going to do that back off.
So I like to nip them on so I know olive is tight, and then usually I take it back off. Or a lot of time I take it back off and I put a bit paste around there. Some people would put PTFE tape around there as well. So if you have a look at that now, that olive, it’s on as it should be, and it’s not squashed right into the pipe. So sometimes what people do is, they tighten the nut far too much, and this olive actually ends up nearly the same size at this pipe, and it leaks. And then they start putting loads of PTFE tape around there then, which is, obviously, it’s such a simple thing to do correctly, but people tend to do it incorrectly. So we’ve got this pipe, we’ve got this olive on the pipe now.
So I’ve got the olive on the copper pipe now. And if we get this brass compression fit in, and if we have a look there, if we push that on there, we can see that that is quite close together. Well, it’s fairly close together. And when that nut is tightened over there, that is how that seals because it’s a tapered edge. Now I’ll show you if now you put it on wrong. Do you see there? You’ve now got a gap. You see that gap? So sometimes, the reason I’m showing you this is, if you change radiator valves, sometimes the old valves, this bit of it is deeper and it’ll go on correctly. And the new valves, because they might want to save a bit of metal, this might be a bit shorter. And when you put that on, so then you might need to cut the olive off to do it. But going back to this one now, we’ve got this pipe like that, so what I do, I take this back out and I would put a bit of paste on this olive here.

So as I say, I would normally put on the pipe here, on the olive, I would put some paste on there. Or that’s what I used to do. I’m going to show you that. I used to use this stuff. It’s been in

Allen Hart

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