The steel pipe wall thickness series comes from the British metrology unit, and the score is used to express the size. The wall thickness of the seamless pipe
is made up of the Schedule series (40, 60, 80, 120) and is connected to the weight series (STD, XS, XXS). These values are converted to millimeters as part of the tube wall thickness series. (Note: Size - the value of Schedule40 is not constant, but to look at the outer diameter of the tube.)
The method of expressing the pipe diameter and thickness, the nominal outer diameter and the minimum thickness of the pipe for the heating surface, the NPS for the pipe pipe and the schedule number of the pipe wall. The wall thickness series consists of 8 series from 10 to 20, 30, 40, 80, 120, 140, 160. The 40 series is the standard series, the 80th is the thick series, and the 120 is the extra thick. series.
The wall thickness of American Standard and domestic standard is quite different. Generally, the two pressure grades of CL.150 and CL.300 are not high. Generally, SCH10S and SCH40 are used. Less than 50 select SCH80 and SCH40S.
, tube number, whether it is domestic or foreign, Sch.XX is used to indicate the wall thickness of the pipe. GB/T81631 HG20553 is also included in the national standard GB/T81631 HG20553, etc., according to the outer diameter of the pipe or the pipe size, the wall thickness of different sizes indicated by the same pipe number are different.
The method for expressing the wall thickness of seamless steel pipe has three methods: pipe gauge size, steel pipe wall thickness dimension and pipe weight:
1) The wall thickness is indicated by the pipe number "Sch".
The pipe gauge number is the ratio of the pipe design pressure to the allowable stress of the material at the design temperature multiplied by 1000 and rounded. Namely: Sch=P/[σ]t×1000
ANSI B36.10 wall thickness rating: Sch10, Sch20, Sch30, Sch40, Sch60, Sch80, Sch100, Sch120, Sch140, Sch160 ten grades;
ANSI B36.19 wall thickness grade: Sch5s, Sch10s, Sch40s, Sch80s four grades;
2) According to the wall thickness of steel pipe, China, ISO, Japan, some steel pipe standards are adopted.
3) The thickness of the pipe wall is expressed by the weight of the pipe, which divides the wall thickness of the pipe into three types:
a. Standard weight tube, expressed in STD
b thickened tube, expressed in XS
c. Extra thick tube, denoted by XXS.
For pipes with DN ≤ 250mm, Sch40 is equivalent to STD, DN < 200mm pipe, Sch80 is equivalent to XS.