Compression fitting

Selecting a compression fitting

A compression fitting is intended for creating a mechanical pipe connection with a compression nut and ring. The pipe is inserted into the fitting, after which the compression nut is tightened and the compression ring grips around the pipe. This creates a secure connection without a press machine, soldering or adhesive. Compression fittings are widely used in heating pipes, water-based installations, service work and situations where accessibility remains important.

The right choice depends on pipe size, material, connection type, fitting design, pressure class, temperature and mounting position. For the broader category, also review fittings for pipework. When a permanent press connection is required, press fitting may be more relevant. For threaded connections, transition pieces and connections to valves, threaded fitting is important.

Important when choosing compression fittings

• Check pipe size, material type, wall thickness and round pipe fit
• Select the right design, such as straight connector, reducer, T-piece, elbow, stop or threaded connection
• Check female thread, male thread, reducer size and connection to valves or appliances
• Check pressure class, temperature range and application within the installation
• Install the compression ring and nut straight, clean and without strain
• Tighten the fitting carefully without deforming or damaging the pipe
• Always check the connection after installation for correct fit and leak tightness

Mechanical connection without press tools

The main advantage of a compression fitting is that the connection can be made without a press machine. This makes these fittings practical for maintenance, repair, renovation and installation in locations where press tools are difficult to use. The pipe must still be cut square, properly deburred and fully inserted into the fitting before the compression nut is tightened.

For installers, the correct installation sequence is especially important. The compression nut, compression ring and pipe must be positioned correctly so the fitting tightens evenly. Insufficient tightening can cause leakage, while overtightening may damage the pipe or compression ring. Always check dimensions, material, technical application and accessibility for later inspection or service.