Straight PEX Fitting SiGMA-Li MZPW251 — 25 x 1 mm female threaded connector

SiGMA-Li MZPW251 is a straight PEX fitting engineered to connect 25 mm cross-linked polyethylene (PEX) piping to a 1 mm female threaded component. The connector creates a watertight transition between PEX tubing and threaded valves, adapters or fixtures, and is intended for plumbing and heating systems in residential and light commercial applications. The body and connection surfaces are designed to align with standard PEX installation practices and to provide a compact, inline joint that preserves flow characteristics.

Advantages

The straight PEX fitting offers a reliable mechanical seal suitable for pressurized potable water and heating circuits when installed according to recommended methods. Its straight design minimises pressure drop and makes alignment straightforward during installation. The female threaded interface allows direct attachment to threaded components without additional adapters, reducing installation time and potential leak points. Materials and dimensions are selected to match common 25 mm PEX pipe sizes for consistent fit and performance.

Suitable for

• Connecting 25 mm PEX tubing to 1 mm female threaded valves and fixtures
• Domestic potable water distribution systems
• Underfloor heating manifolds and heating circuits in light commercial settings
• Repair or retrofit where a PEX-to-threaded connection is required

Key specifications

• Compatibility: 25 mm cross-linked polyethylene (PEX) pipe
• Thread type: female threaded connection with 1 mm nominal thread size
• Geometry: straight inline fitting for axial connections
• Application: potable water and heating installations
• Installation method: mechanical compression/insert style suitable for standard PEX joining techniques

How to use

Prepare the PEX pipe by cutting squarely and deburring the end. Slide any required ferrule or compression sleeve onto the pipe, then insert the supplied or compatible PEX insert until the pipe seats fully. Engage the fitting body onto the prepared pipe according to the manufacturer's joining procedure and tighten the female threaded connection to the mating component with appropriate tools, ensuring not to exceed recommended torque values. After assembly, check the connection for leaks by pressurising the system and visually inspecting the joint.

Usage recommendations

Use this fitting only with compatible 25 mm PEX tubing and threaded components of matching thread form. Follow local plumbing codes and manufacturer installation instructions. Where accessible, apply thread sealant or tape on the threaded interface as required by the specific valve or fixture manufacturer. Verify system pressure and perform a leak test before concealing the installation.

SiGMA-Li MZPW251 — 25 x 1 mm female threaded connector