MDPE Universal Transition Coupling 20mm to 32mm

The MDPE Universal Transition Coupling is a straight fitting that joins blue MDPE water pipe to copper, sold in 20mm x 15mm, 25mm x 22mm and 32mm x 28mm for plumbers connecting a new or renewed main to the pipework inside. The size reads MDPE first, then copper.

The main outside is usually MDPE and the pipe indoors is often copper, so this is the fitting that sits at the changeover: under the floor near the stopcock, in a meter box, or where a repair joins new plastic to old copper. The universal end grips a range of sizes, which also helps where older pipe is not quite the size you expect.

Fit a liner in the MDPE first, cut both pipes square and keep site grit out of the joint. Check the grip range on the body against your pipe before you tighten. If you also need to turn a corner, the transition bend does both jobs in one. Liners and stop valves are with our MDPE universal transition couplings.

Specification

• Connection: Compression for MDPE x compression universal end
• Sizes: 32mm x 28mm, 25mm x 22mm, 20mm x 15mm
• Suitable for: Joining MDPE to copper on cold water supplies

Common Questions

Which size suits a normal house? Most houses have a 25mm MDPE main changing to 22mm copper, so the 25mm x 22mm is the common one. The 32mm x 28mm is for larger supplies and the 20mm x 15mm for small feeds.

Can it go on pipe other than copper? The universal end grips a range of outside diameters, so it can take some other pipe types of the right size. Check the materials and range marked on the fitting before you rely on it.

Do I need a pipe liner in the MDPE? Most makers of MDPE compression fittings ask for a liner in the pipe end, and it is good practice either way. The liner keeps the pipe round under the nut so the joint grips and doesn’t creep. Check the leaflet in the bag for the size of liner to use.

Is 25mm MDPE 25mm inside diameter? No. MDPE is sized on the outside, so 25mm pipe measures 25mm across the outside and the bore is smaller. Measure the outside of your pipe to choose the fitting.

Come in to our Glasgow shop at 555 South Street G14 0QX or buy online. Hours: Mon-Fri 8am-5pm, Sat-Sun 8am-1pm.