1/2 inch x 7lb Lead to 25mm MDPE Lead Line Coupling

Our 1/2″ 7lb Lead to 25mm MDPE Coupling is a brass Lead Line fitting that takes half inch, 7lb lead on one side and 25mm MDPE on the other. Half inch 7lb is the lead size we see most on older house supplies, and this suits plumbers bringing in a new MDPE supply.

If you’re bringing a new 25mm MDPE supply into a house and the lead is staying for part of the way, this is the joint between them. It also works for repairs: cut out a cracked or kinked section of lead and run MDPE in its place. Using 25mm on the new side gives a decent bore for a combi or several outlets at once.

Half inch lead is made in several weights and the outside diameter changes with each, so a 7lb coupling won’t seal properly on 6lb or 9lb pipe. Measure before you buy. We also carry a 20mm MDPE version if the new pipe is 20mm. Square off and re-round the lead, fit an insert in the MDPE, and tighten to the instructions supplied. The 1/2″ 7lb Lead to 25mm MDPE Coupling sits with the rest of our lead pipe connectors.

Specification

• Brand: Lead Line
• Material: Brass
• Connection: 1/2 inch lead (7lb) x 25mm MDPE compression
• Sizes: 1/2 inch 7lb lead x 25mm MDPE
• Suitable for: Cold mains water supply pipe

Common Questions

What does the lb number on lead pipe mean? It’s the weight of the pipe per yard, and it tells you the wall thickness. Two pipes with the same bore but different weights have different outside diameters, so a set for one weight won’t grip the other properly.

Does the MDPE end need an insert? Yes. Fit a 25mm pipe insert (liner) in the MDPE so it doesn’t collapse when the fitting is tightened. Push the pipe fully home before you tighten.

20mm or 25mm MDPE: which should I use? For a new full house supply most installers now go 25mm for better flow. Use the 20mm version only where you’re joining an existing 20mm pipe.

Should I replace the lead pipe instead? Where you can, yes. Scottish Water advise replacing lead supply pipe, and a lead connector is best seen as a link between old and new until that’s done.

Call in at 555 South Street, Glasgow G14 0QX, or order online and collect. Open Mon-Fri 8am-5pm, Sat-Sun 8am-1pm.