Stainless Seamless Steel Tubes Inside And Out Side Polishing EP, BA, AP Pipeline Cleanliness Level
Name: Stainless steel EP pipe (electrolytic polishing pipe)
Production standard: GB national standard, ASTM American standard, JIS Japanese standard, DIN German standard
Steel pipe materials: 304, 304L, 316, 316L, 316Ti Monel400, etc.
Pipe standard: Metric (ISO) English (Inch) Japanese (A)
Pipe classification: acid washing, mechanical polishing, bright annealing, electrolytic polishing
Pipe specification: Metric (ISO): Φ 3mm~ Φ 76mm Inch: 1/8 "~3"
Processing technology: After multiple cold rolling and cold drawing processes, the inner and outer diameters are fixed and polished to form.
Product accuracy: The tolerance range is controlled below 0.02mm, and the outer wall roughness is around 0.25um.
Product packaging: nitrogen blowing, single bag, two end caps, non-woven fabric packaging.
Application fields: Instrument, instrument, petroleum, pharmaceutical, chemical, water supply cleaning, gas, pressure vessel, testing and other industries.
Meaning of EP, BA, AP pipeline cleanliness level
1, Pipe fittings
A. According to material classification, pipes can be divided into:
(1) SUS 304
(2) SUS 316
(3) SUS316L
The lower carbon content is too low for orbital welding, as the steel has less carbon precipitation during high-temperature fusion, which can ensure that the material is not brittle (refer to Table 1-1).
B. Classification by specification
(1) JIS: Pipe Size
(2) ASTM: TUBE SIZE
It should be noted that
(i) The size of 1 "is in pipe size=25A, with an outer diameter OD of 34.4mm, and in tube size, its OD is 25.4mm
(ii) In Pipe Size: 25A, also known as 1 ", 50A, also known as 2" 80A, also known as 3 "100A, also known as 4"
(iii) TUBE SIZE (usually used in GAS piping below 1 "), commonly used sizes are 1/8" (one part), 2/8 "(two parts), 3/8" (three parts), 4/8 "(four parts), 5/8" (five parts), 6/8 "(six parts), 1"
C. Classified by surface treatment methods: generally divided into three types
(I) AP grade (plain tube): no surface treatment
(II) BA level: Radiant Burn Blunt
(III) EP level: electrolytic polishing
Attention: The most important determining factor affecting the price of pipes is the surface treatment method, and the order of price is EP>BA>AP.
D. Distinguished by thickness: General thickness specifications include SCH5S, SCH10S, SCH20S, and SCH40S.
E. Pipes can be divided according to the manufacturing process
(I) SINGLE MELT
(II) DOUBLE MELT (aimed at reducing impurities in the pipe and increasing corrosiveness)
Example: VIM+VAR (patent name for SUMKIN)
VIM - VACUUM INDUCTION MELTING
VAR - VACUUM ARC REMELTINGF
Pipe materials can be divided into two types: seam and seamless
2, Connection of pipes
(1) SWG (SWAGELOK)
(2) VCR
(3) BUTT Welding
(4) SCREWED
(5) FLANGE
(6) QUICK CONNECTOR
3, Precautions for selecting pipes:
(1) Need to consider the properties of the fluid inside the pipe (flow rate, pressure, temperature, corrosion properties)
(2) Generally, BULK GAS (GN2, CDA, Ar, H2, O2) is used, among which BA grade is used for GN2 and CDA. The other BULK GAS and APECIALTY GAS are all made of EP grade pipe material, SUS316L. Sometimes, due to cost considerations, owners may consider using SUS304 for GN2 and CDA as power sources for pumps.
(3) If SUS304 is used, the thickness of the locking nipple should be SCH10S or above.
(4) VIM+VAR is generally used on highly corrosive gases, such as BCL3, WF6, CL2, HBr, etc.
Attached Table: 1. Comparison Table of Rmax, Rz, and Ra Values for Testing the Same Sample (Unit: um)
2, The purpose of setting chemical composition specifications for SUS316L stainless steel pipe material:
NO chemical composition Wt/%
JIS G4303 ASTM A269
Purpose 1
C 0.030
(1) Prevention of CARBON acidification contamination during dissolution
(2) During welding, CARBON may contaminate the pipe if released
Si 1.00
(1) Reduction of non-metallic substances (SiO2)
(2) Improved quality during fusion welding
Mn 2.00
(1) Reduction of non-metallic substances (MoS)
(2) Prevention of Pollution and Corrosion Resistance Deterioration of Mn FUME during Fusion Welding
S 0.030
(1) Reduction of non-metallic (MnS)
(2) Improved quality during fusion welding
AL
(1) Reduction of non-metallic (Al2O3)
(2) Improved quality during fusion welding
N
(1) Reduction in gas release
O
(1) Prevention of the formation of non-metallic substances
H
(1) Reduction in gas release
(2) Prevention of PINHOLE occurrence
Ni main component control
(1) Safety of dissolution conditions
(2) Rise of Fusion Quality
Cr Mo 2.00-3.00
