Views: 0 Author: Kath Publish Time: 2024-09-13 Origin: Site
Carbon steel pipe is one of the most widely used pipe materials at present, but there are some limitations in the use process. One of them is the limit value of its tolerance to negative pressure.
The pressure resistance of carbon steel pipe depends on many factors such as its material, wall thickness, outside diameter and service conditions.
(1) Wall thickness: The larger the pipe wall thickness and the smaller the pipe diameter, the stronger the resistance to negative pressure.
(2) Material: The same thickness of carbon steel pipe and stainless steel pipe in terms of tolerance to negative pressure, stainless steel pipe performance is better, followed by galvanized steel pipe and seamless steel pipe, and then ordinary carbon steel pipe.
(3) Temperature and pressure resistant:
With the increase of carbon content, the toughness and brittleness transition temperature of the steel will rise, and the lower limit of the use temperature of the No. 20 carbon steel pipe is 0℃.
When the ambient temperature is lower than -20℃ for welding, the joint should be preheated to more than 100℃ before welding.
(4) Connection:
The connection method of carbon steel pipe will also affect its pressure resistance, such as threaded connection, welded connection, groove connection, flange connection and clamp connection, etc. Each connection method has its applicable occasions and limitations.
In addition to the pressure resistance of carbon steel pipes, there are the following important physical performance indicators: tensile strength (Rm), yield strength (Re), elongation (A), hardness (HB), impact toughness, chemical composition, surface quality, etc.
(1) Pipeline deformation
Carbon steel pipes with thicker tube walls should be selected to enhance the negative pressure bearing capacity.
(2) Pipe burst
A shock absorber can be installed at the pipe joint to absorb the influence of negative pressure on the pipe.
(3) Pipeline leakage
Rubber sealing rings or polytetrafluoroethylene sealing gaskets can be installed at the joint of the pipeline to improve the tightness of the pipeline.
