Guest 3/8x1/4 R M Ell

Combining a size reduction with a 90-degree turn, the John Guest 3/8" x 1/4" Reducing Male Elbow from Reliance Worldwide Corporation is a versatile fitting for tight filtration and reverse osmosis installations. It connects 3/8" push-in tubing to a 1/4" male iron pipe thread while redirecting the line around a corner, doing the work of two fittings in a single low-profile body.

This elbow solves two problems at once. Rather than stacking a separate reducer and a separate elbow, you get both functions in one piece, which means fewer joints, less assembled height, and fewer potential leak points behind a crowded filter housing. The threaded 1/4" MIPT end mates with tapped ports on filter heads and valves, while the 3/8" collet grips standard tubing securely and seals it with an internal O-ring.

Key Features

• Connection: Tube x MIPT with a built-in 90-degree bend
• Reduces 3/8" tubing to a 1/4" male thread in one piece
• Molded polypropylene resists corrosion and scaling
• Push-fit tube end seats instantly without tools
• Saves space behind compact under-sink systems
• Fully demountable for servicing and rework

To install, apply PTFE tape to the male thread and tighten it into the port, orienting the elbow so the tube outlet faces the direction your run needs to travel. Then cut your 3/8" tube square and free of burrs, push it fully into the collet until it bottoms out, and confirm the grip with a gentle tug. The polypropylene construction resists the corrosion and scale that can plague metal fittings over years of service with treated water. When maintenance is required, depress the collet to release the tube cleanly, then refit it once the work is done. Demountable, reusable, and genuinely space-saving, this John Guest reducing male elbow keeps water treatment plumbing compact and leak-free even in the tightest cabinets.

As part of the John Guest range, this reducing elbow integrates with the unions, tees, valves, and connectors that share the same collet system, so you can build and later modify an entire compact layout from interchangeable parts. That shared design is what lets installers route tubing through cramped cabinets confidently, knowing every junction assembles tool-free and releases the same predictable way when service time comes.