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Butt-welding pipe fitting

Butt-welding pipe fitting is a plumbing component used in piping for supplying steam, water, oil, gas and air in nuclear power plant, hydro power plant, thermal power plant, shipbuilding plant, petrochemical plant, and central and district heating plant, etc.


What is pipe fitting?
It is used when changing the direction or diameter of piping, or installing piping that bifurcates from the main pipeline. They are manufactured by using steel plate or pipe, or by mechanical processing of molded products with forged plate. They are classified as follows.

Classification according to the method of alignment (coupling method)

B.W (Butt Welding) Coupling through welding by improving the 2 sections that come in contact with prescribed angle (the most economical method of maintaining airtightness in piping with large diameters)
S.W (Socket Welding) Used mostly for piping with diameters of less than 2"(50A), and is particularly useful in transportation of inflammable, toxic and radioactive fluid
Thread Type Coupling method of tightening of threading and used mostly for piping with diameter of less than 2"(50A)

Classification according to the materials

(1) Carbon Steel
(2) Stainless Steel
(3) Alloy Steel
(4) Duplex, etc.


(1) Piping in the main process (Process Line) is used for transportation of fluid between storage tank and processing system, while the piping in the auxiliary process (Service Piping) is used for transportation of steam, air and water for the main process (Process Line).

(2) Although Service Piping is also referred to as Utility Piping, Utility Piping generally refers to the piping line for supplying of utilities such as combustion substances such as oil, which are purchased in bulk.

(3) Although there are various formats of piping used in ships, carbon steel pipes that are connected by means of welding and thread type coupling of pipes and plumbing materials are used mostly.

(4) Transportation piping are composed mainly of pipes with large diameters and applied to transportation of fluid, slurries (mixture of insoluble substances such as plaster and limestone with water) and gas, etc. over a distance of several hundred miles. For example, it is used for transportation of crude oil, petroleum and water, etc.

(5) Facility piping is used for the purposes of supplying water and combustion gas necessary for facilities in schools, buildings and homes, and to collect waste water.