The main task of fitting is to connect securely several parts of the same or different diameter pipelines between themselves and their attachment to various tanks, compartments and special equipment.

1. Welded fitting
   
   serves to bind the branches of the pipeline, joining valves, taps. This type is used for installation of pressure gauges on the pipeline and process equipment. The shape of the other end of fitting depends on the method of joining to the subsequent part. For example, at one end of the welded fitting can be cut internal or external thread. They are used in a wide temperature range at the nominal pressure of 16 MPa. They have different climatic modification in accordance with GOST. Welded fittings are made of stainless steel or alloy steel.
2. Transition fitting
   
   is used to interconnect elements of the pipeline system. It can connect parts of the same diameter and different diameters. Transition pipe fittings are used to connect pipes to various tanks and devices, they can be used for discharging water or steam, water extraction from the pipeline in order to change its pressure.
3. Swivel fitting
   
   serves to create a rotary joint in the pipeline which is necessary for feeding gas, liquid or vapor into the movable system node. The design of the swivel fitting depends on the direction of operating fluid flow. Fittings of this type are designed for bidirectional liquids, they prevent leakage and mixing of the operating fluid at the inlet and outlet.