How Are Stainless Steel Sanitary Pipes Graded?

How Are Stainless Steel Sanitary Pipes Graded?

Stainless steel sanitary pipe and fittings are generally divided into three types according to surface treatment methods: AP grade stainless steel pipe refers to the surface of the pipe that has not been treated; BA type pipe refers to the use of bright burnt treatment; EP grade stainless steel pipe refers to the use of electrolytic polishing treatment.

Note: The factor that affects the price of stainless steel sanitary pipes is the most important determinant in the surface treatment method, and the price order is EP> BA> AP. According to the thickness: the general stainless steel thickness specifications are SCH5S, SCH10S, SCH20S, SCH40S. Stainless steel pipes can be divided according to the manufacturing process: single fusion; double fusion (the purpose is to reduce impurities in the pipeline and increase corrosion), stainless steel pipelines can be divided into seamless and seamless.

Stainless steel connection is SWG (SWAGELOK), VCR, BUTT WELDING butt welding, lock teeth (SCREWED), flange (flange), QUICK CONNECTOR (quick joint)

Notes on the selection of stainless steel pipes:

(1) Need to consider the nature of the fluid in the pipeline (flow, pressure, temperature, corrosiveness)

(2) General bulk gas (GN2, CDA, Ar, H2, O2), where GN2 and CDA use BA grade, other BULK GAS and APECIALTY GAS use EP grade pipe, the material is SUS316L, sometimes, the owner also considers GN2 With CDA as the power supply for PUMP, SUS304 will be considered.

(3) If SUS304 is used, the thickness of SCH10S or more is required for the locking teeth.

(4) VIM + VAR is usually used for highly corrosive gases, such as: BCL3, WF6, CL2, HBr, etc.

Rmax, Rz, Ra value comparison table of the same sample (unit: um)

Sample No. internal Rmax Rz Ra
1 BA 1.82 1.62 0.39
2 BA 1.92 1.72 0.16
3 BA 2.52 1.72 0.32
4 EP 0.20 0.15 0.04
5 EP 0.45 0.24 0.07
6 EP 0.89 0.73 0.07