Ways of connecting pipes
Steel pipe is now fully welded, except for the joints, which should be undertaken in addition to clothing, which is flanged. It is important that the welding is performed by the competent masters and undergoes a thorough inspection.
Flanges for ammonia (and, preferably, also, other refrigerants) should be bright and grooved type that await gasket. Copper pipes must use a solder joint. This can be bent to shape in the smaller size and the use of the springs bending or stabilizers is recommended to keep a complete bore.
Where fittings are necessary, they must be of copper or brass, to give a correct capillary joint gap of not more than 0.2 mm, and joined with solder. Soldering copper pipes in the air will leave a layer of copper oxide inside that could come loose and travel around the circuit. Therefore, you must pass the nitrogen in the pipeline heating, and to maintain flow until soldering completed. The use of special marks of oxygen or moisture-free nitrogen is not necessary.