1/2 inch x 7lb Lead to 20mm MDPE Lead Line Coupling

The 1/2″ 7lb Lead to 20mm MDPE Coupling joins half inch lead of the common 7lb weight to 20mm MDPE. It’s a brass Lead Line fitting for plumbers and groundworkers working on existing 20mm supplies.

Twenty millimetre MDPE was the standard size for house supplies for a long time and is still common on existing runs, garden supplies and feeds to outbuildings. If the MDPE you’re tying into is already 20mm, or you’re making a short repair on a 20mm line, this is the coupling to use. For a new full supply most installers now go up to 25mm, and we stock a 25mm version as well.

The 7lb figure is the weight of the lead per yard, and it decides the wall thickness and outside size. Check it against your pipe with callipers, as 6lb or 9lb pipe needs a different coupling. Cut the lead square, round it back up if it’s been squashed, and use an insert in the MDPE end. Support the lead near the 1/2″ 7lb Lead to 20mm MDPE Coupling. More options are in our lead pipe connectors range.

Specification

• Brand: Lead Line
• Material: Brass
• Connection: 1/2 inch lead (7lb) x 20mm MDPE compression
• Sizes: 1/2 inch 7lb lead x 20mm 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 20mm pipe insert (liner) in the MDPE so it doesn’t collapse when the fitting is tightened. Push the pipe fully home before you tighten.

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.

Does swapping lead for plastic affect the earthing? It can. If metal pipe that formed part of the earth path is replaced with plastic, the bonding needs checking and may need a jumper. Get an electrician to look if you’re unsure.

Collect from our Glasgow shop at 555 South Street G14 0QX or order online. Open Mon-Fri 8am-5pm, Sat-Sun 8am-1pm.