HVAC technology: What are the general requirements for the layout of pipe fittings (petrochemical industry)

(l) Elbows should be long-radius elbows with a radius of curvature equal to 1.5 times the nominal diameter. Pipes that convey gas-solid or liquid-solid two-phase flow materials should use elbows with large radius of curvature.

(2) For horizontal pipe reducer connections on corridors, if there are no special requirements, bottom-flat eccentric reducers should be used. Concentric reducers should be used on vertical pipes.

(3) For centrifugal pumps with horizontal suction, when the inlet pipe changes diameter, an eccentric reducer should be installed near the pump inlet. When the pipeline enters the pump from bottom to top, top-flat installation should be adopted; when the pipeline enters the pump from top to bottom, bottom-flat installation should be adopted.

(4) Flat-weld flanges should not be directly connected to elbows without straight pipe sections.

(5) Valves and other static sealing joints should be installed near the pipe support points.

(6) Unless there are special process requirements, flanges and threaded joints shall not be arranged on the pipes in the skirts of equipment such as towers, reactors, and vertical vessels.

(7) Carbon steel pipelines of the pump lubricating oil system and pipelines for conveying solid deposits and coking media should be provided with flanges in sections. The number of elbows on each section of the carbon steel pipeline of the pump lubricating oil system should not exceed 2.

(8) The end of the lubricating oil main pipe of the pump lubricating oil system should be closed with a flange cover.

(9) The reducers on the pipelines on both sides of the regulating valve should be close to the regulating valve.

(10) When using a reducing flange connection, the flow direction of the conveying medium should be from the small diameter to the large diameter.