LK Armatur Our websites English

Our websites

Assembly Instructions for Compression Fittings

Assembly Instructions for Compression Fittings

Assembly Instructions for Compression Fittings.

Assembly Instructions for Compression Fittings


Detailed Information


Compression fittings are produced in high quality brass. As any copper-based material, brass is potentially subject to stress corrosion cracking. When compression fittings are used in cooling systems, this risk for stress corrosion cracking may be higher than in heating applications. This is due to the development of moisture that can contain some amount of ammonia or its derivates.

The following good-installation practice shall be used when installing compression fittings in cooling systems in order to eliminate or, at least, to minimize the risk for stress corrosion cracking:
• Lubricate the compression fitting before installation.
• Only use box spanners during installation.
• Tighten first by hand and then with a box spanner. Do not overtighten. Spanner tightening as per the table below.
• After the compression fitting is tightened, wrap it by using an ”ammonia-free” impervious tape. This will protect the nut against moisture. Please, consider that certain insulation materials develop ammoniacal derivatives - contact the manufacturer of the insulation material when in doubt.

Soft pipes are to be fitted with a support sleeve.
• Soft copper and steel pipes = Use a type SC support sleeve
• PEX pipes = Use a type WP support sleeve.

For fitting with reduction 68:
First tighten the nut until the chamfer “fails” and a “crack” is heard. Then tighten the nut further until a light resistance is felt, plus number of turns as per the table value ­corresponding to the reduced dimension. The reduction is not intended to be used on PEX pipes.

Technical Data


Tightening - Number of turns