Straight double union for flat gasket Comap 18×3/4 — model 4359 GL

Straight double union Comap 18×3/4 — model 4359 GL is a mechanical connector designed for joining two pipe ends or fittings with a flat gasket seal. Manufactured by Comap, this straight double union is intended for plumbing and heating systems where a reliable, compressive gasket joint is required. The component provides a compact inline connection with a union nut on each side to compress the flat gasket and ensure a leak-resistant joint in potable water or heating circuits.

Advantages

The straight double union offers a simple, serviceable connection that can be assembled and disassembled without rotating the pipes, easing maintenance and replacement. The flat gasket interface provides uniform sealing pressure and is compatible with common gasket materials used in plumbing installations. Its straight, inline design minimizes flow disturbance and fits standard 18×3/4 connection dimensions used in residential and commercial systems.

Suitable for

• Connecting copper, steel or plastic pipe fittings in domestic plumbing
• Joining sections in heating circuit manifolds and radiators
• Installations where a flat gasket seal is specified
• Maintenance tasks requiring frequent disassembly and reassembly

Key specifications

• Connection type: straight double union with flat gasket sealing
• Nominal size: 18×3/4 (compatible with corresponding threaded fittings)
• Material: corrosion-resistant metal suitable for potable water and heating systems
• Sealing: flat gasket compressed by union nuts for uniform pressure
• Design: inline, union-nut assembly for non-rotational pipe disconnection

How to use

Prior to installation, ensure mating surfaces and the flat gasket are clean and free of debris. Insert the gasket into the union seat and align the two pipe ends or fittings. Hand-tighten both union nuts, then use appropriate wrenches to tighten to a level that compresses the gasket evenly without over-torquing. After assembly, pressurize the system and inspect for leaks; if leakage is detected, slightly retighten the union nuts or replace the gasket if damaged. For disassembly, loosen the union nuts and separate the connection without rotating the pipes.

Usage recommendations

Use gasket materials compatible with the system medium and temperature. Avoid excessive torque on union nuts to prevent gasket deformation. When used in heating systems, verify compatibility with system pressures and temperatures and perform a pressure test after installation.