What do BA grade, EP grade, AP grade and MP grade of stainless steel pipe mean?

Stainless steel BA tube - Bright Annealed tube (vacuum bright annealed tube), it is the abbreviation of atmosphere protection heat treatment (Bright Annealed), also known as: stainless steel BA tube, clean tube, bright annealed tube, seamless tube, gas line tube, high-purity gas line pipeline, ferrule tube.

Material: 304,316L
Standard: ASTM A249, A269, A270, 3A and BPE standard, JIS G3447. G3459.
Forming: mainly multi-roll cold rolling, the dimensional accuracy can reach 0.2%, the inner surface finish Ra< 0.45 um.
Features: precise size, smooth surface, overall cleanliness, the inner surface is not polished better than polished finish.
Raw materials: meet ASTM A269 standards, special requirements can use two furnace steel ingots.
Manufacturing: cold rolling + fine drawing, dimensional accuracy reaches about 0.05mm, inner surface Ra is about 0.4 microns.
Heat treatment: Bright solution treatment (annealing) under the protection of reducing atmosphere
Cleaning: Ultrasonic cleaning with SC2286 cleaning agent, that is, degreasing and deoiling must be done.
Inspection: Eddy current non-destructive testing + water pressure and other methods
Finishing: Straightening + sizing + polishing
Packaging: Coding + PE bag + cap + shock-absorbing packaging + dust packaging + protective protection
Use: Special gas or liquid transportation, and it is also the parent material of EP pipe.
Applicable industries: biopharmaceuticals, electronic clean workshops, high-purity gases, high-requirement clean laboratories, liquid crystal displays, solar photovoltaics, polysilicon and other fields, semiconductor industry, liquid crystal industry, pharmaceutical industry, instrumentation system, compressed air, ultra-high purity gas, chemical system, WFI system and other gas pipeline systems or clean rooms or equipment with high purity and ultra-high purity requirements.

EP process: Electrochemical polishing of the inner surface on the basis of high-quality BA pipe, then purification with high-purity water, and nitrogen filling packaging.
Diameter control: tolerance ±0.02mm (0.1%);
Length control: tolerance ±0.05mm;
Straightness: not more than 0.1mm/m;
Surface roughness: EP tube Ra≤0.15 μm;
Concentricity control: tolerance ±0.01mm;
Mechanical property control: hardness HRB (75~580), strength δb and elongation Ψ can be adjusted and controlled;
Heat treatment: solution treatment in reducing atmosphere.
Packaging: double-layer bagging with cap.

AP: Acid pickling (Anneal treatment & Passivation) /(Acidpickling)
MP: Mechanical polishing
BA: Bright annealing treatment/(Bright Annealing)
EP: Bright annealing---> non-destructive testing---> chemical polishing----> electropolishing
BA: Bright annealing---> non-destructive testing---> one-time cleaning;
CP/AP: Heat treatment---> non-destructive testing---> chemical polishing