3/4 inch x 1 inch PEX Engineered Plastic Insert Coupling PEX x PEX

Uponor ProPEX EP Reducing Coupling – 3/4" PEX x 1" PEX, Engineered Polymer

The Uponor ProPEX EP Reducing Coupling (3/4" PEX x 1" PEX) is designed to transition between two different PEX pipe sizes in potable water and hydronic systems. Manufactured from engineered polymer (EP), this fitting offers corrosion resistance, high dimensional stability, and reliable performance in both hot and cold water applications.

This reducing coupling is part of the Uponor ProPEX system and is intended for use exclusively with Uponor PEX-a tubing. It is installed using the ProPEX expansion method, which eliminates the need for soldering, gluing, or crimping. This joint method creates a strong, consistent seal that resists pull-out and long-term system degradation.

Key Technical Features

• ✅ Material: Engineered polymer (EP), lead-free and resistant to pitting, corrosion, and mineral buildup
• ✅ Connection: 3/4" PEX-a x 1" PEX-a, ProPEX expansion ends
• ✅ Temperature/Pressure Rating: 200°F at 80 psi, 180°F at 100 psi, 73.4°F at 160 psi
• ✅ Compliance: NSF 14, NSF 61, NSF 372 certified; ASTM F1960 and CSA B137.5 compliant
• ✅ Application: Suitable for residential and commercial potable water systems, as well as hydronic distribution

Installation Guidelines

Install using an approved ProPEX expander tool and compatible PEX-a pipe and expansion rings. Ensure full expansion and proper seating of the pipe over the fitting barb. No solvents, glues, or mechanical clamps are required. ProPEX connections should be inspected for full engagement and allowed to relax before pressurization per manufacturer recommendations.

Typical Use Cases

This reducing coupling is commonly used in transition points within multi-zone distribution manifolds, fixture branches, and retrofit conditions requiring size reduction between 3/4" and 1" PEX lines. It supports both vertical and horizontal orientations in open or concealed system layouts.

Material Insight

Engineered polymer is chemically stable, resistant to scale and corrosion, and has no reaction with potable water or glycol-based hydronic fluids. It is a non-metallic alternative to brass, ideal for areas with aggressive water chemistry or where dissimilar metal corrosion may be a concern.

The Uponor ProPEX EP 3/4" x 1" Reducing Coupling delivers durable, code-compliant connections in PEX-a plumbing and heating systems. It ensures long-term mechanical reliability with reduced risk of joint failure or service interruption.