1. Armatex
  2. Guides
  3. Choosing a fitting for PE pipe: sizes, liners and transitions
Guide · 4 min read

Choosing a fitting for PE pipe: sizes, liners and transitions

PE pipe, e.g. on a water service connection, often needs to be connected to copper or a thread. We show how to choose a fitting from the Kuterlite K700 series in five steps.

Selection in five steps

  1. Pipe outside diameter. K700 fittings come in sizes 20, 25 and 32 mm. The fitting size is the outside diameter of the PE pipe.
  2. Metric or imperial? Old imperial pipes (BS 1972 and BS 3284 standards) are connected using the K710IM adaptor: 20 mm × 1/2″, 25 mm × 3/4″, 32 mm × 1″.
  3. What are we connecting to? PE × PE, PE × copper or PE × thread (table below).
  4. Liner. K766M in the pipe size (20–63 mm). For BS 1972 class C imperial pipes there is K1766C (3/8″, 1/2″, 3/4″).
  5. Spare parts. K778A nuts and K778B rings are also available individually, in sizes 20, 25, 32 and 63 mm.

Transitions from PE pipe

NeedFittingSizes
PE × PE, straightK71020, 25, 32 mm; reducers 25 × 20 and 32 × 25 mm
PE × copper, compressionK710KP20 × 15, 25 × 22, 32 × 28 mm
PE × copper, solderK701 (with a lead-free solder ring)25 × 22, 32 × 28 mm
PE × male threadK711, elbow K71620 × 1/2″, 25 × 3/4″, 32 × 1″
PE × female threadK712, elbow K717, wall-plate K717W20 × 1/2″, 25 × 3/4″, 32 × 1″
Branchtees K718, K718B, K73020, 25, 32 mm

A PE size reduction can also be made with the K748R set (25 × 20, 32 × 20, 32 × 25 mm).

Before you hand over the goods

  • Ask the customer for the pipe’s outside diameter, not the “inch” size. A 25 mm PE pipe is not a 3/4″ pipe.
  • For every PE fitting, add a liner in the pipe size.
  • The pressure and application of the installation also depend on the PE pipe itself. For non-standard applications, we will confirm the selection against the manufacturer’s documentation.

Data source: Kuterlite price list (October 2024). As of 2026.

Call