(1) elbow, seamless elbow commonly used in the bending part of the pipe, to change the direction of the pipeline.
Commonly used are 45 ° elbow and 90 ° elbow. Bending radius is about 1.0 times the pipe diameter called short radius elbow; The pipe is about 1.5 times the outer diameter of the pipe called long radius elbow. The short radius elbow is usually used in the installation position of the pipe system or in order to reduce the cost. The oblique elbow is usually used for the large size pipeline with low pressure (design pressure S2. 0 MPA), water and similar fluid medium conditions relatively moderate. When the direction angle of the single node of the oblique bend is more than 45, the operating pressure should not exceed 0.8 times of the same specification long radius elbow. Not suitable for toxic and combustible media pipelines, or subjected to vibration, pressure fluctuations and temperature changes due to alternating loads on the pipeline.
(2) reducing joint, short reducing joint is used for the linear connection of two pipes of different sizes, There are concentric reducers and eccentric reducers.
The centerlines of the two pipes connected by the concentric reducer are in a straight line. The Straight Segment Reducer Joint, GB12459 – 2005 (DN20X15 ~ 500 ~ 300) is made of seamless steel pipe. Without straight side reducers, GB / TI.MOI (DN350 × 300 ~ 1200 × 1000) is made of steel plate or steel strip. Generally, large diameter pipe connection with reduced-diameter joints using steel plate and steel strip manufacturing cheap, economic good but without straight edge section reduced-size joints, The alignment of the welding groove is more difficult than the straight side section reducers. In small diameter pipe (DN 50 or less), Reducers are often used instead of reducers for pipe sizing. They can be concentric or eccentric.
(3) the role of the branch pipe connection pipe is drawn from the main branch pipe, there are three, four, branch pipe Taiwan, half pipe joints, etc. Three for the main pipe and branch pipe mutually connected parts, There are usually equal diameter tee, reduced diameter tee and inclined tee. Inclined tee is often used instead of tee for conveying solid particles or more serious erosion corrosion pipeline.
(4) pipe joints are used for straight line connection, such as meters, connection forms have socket welding or thread connection.mainly used for small caliber low pressure pipeline, It is used for the parts that need to be assembled and disassembled frequently, or as the final adjustment of the pipe line using threaded pipe. Gasket seal structure is usually used in the transmission of water, oil, air and other general pipeline, using malleable iron material.In addition, the use of requirements and prices are also selected to consider factors.
(5) pipe cap for pipe end closed fitting. The same purpose also often use blind flange, in order to facilitate pipe blowing and cleaning. Generally, according to the requirements of pipe connection size, And consider the economy or the possibility of future expansion of the project and other requirements to determine the use of cap or blind flange pipe cap connection form thread socket and welding connection.
