Electropolished stainless steel tubing is usually called EP stainless steel tubing, and it is mostly used as high purity & UHP (Ultra-high purity) stainless steel tubing. Our factory is a leading China electropolished SS tubing manufacturer & supplier. We produce and supply a wide size range of electro-polished stainless steel tubes, pipes and EP fittings with the most popular stainless steel grades.
Our Electro-polished (EP) tubing Brief Introduction
■ Seamless cold finished tubes / welded stainless steel tubing
■ Material: 316 / 316L, 304 / 304 L, 316Ti, 2205, S31803; EN DIN steel grades 1. 4401 / 1.4404 /1.4435, 1.4301 /1.4307, 1.4462
■ Tubes are suitable for orbital welding
■ Inner surface Elector-polishing;
■ Size Range: Metric dimension outer diameter 5 mm to 100 mm; imperial dimension 1/4 inch to 4 inch
■ Tube Cleaning: Each EP SS tube & EP pipe will be chemical cleaned and DI Water Rinsing as the final cleaning process.
■ Tube Marking: Manufacturer’s name(on request), Product Standard, Material steel grade, Size (OD x WT x Length), and Heat number.
■ Tubing Packing: Tube ends capped with polyethylene caps, every tube packed in double polyethylene bags.
Details of our electropolished stainless steel tubing / EP tubing
Electropolished stainless steel tubing produce standard
As one of the leading China electropolished tubing manufacturers & suppliers, our factory produces and supplies stainless steel electro-polished tubes & pipes with most popular international standards. Here below is the typical list of the most popular standards we follow.
| Fractional Sizes Tubing | Metric and Imperial Sizes Tubes | |||||||||||||||||||||
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ASTM A269 |
ASTM A269 / A270 |
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Besides the above, we also produce electro-polished tubing stainless steel as per other standards or specifications as per customers’ requests.
Electropolished tubing /EP tubing materials
As the professional EP tubing manufacturer, our factory produces electro-polished tubing with stainless steel grades as below.
AISI / UNS steel grades: 316 / 316L, 304 / 304 L, 316Ti, 2205, S31803
EN DIN steel grades: 1. 4401 / 1.4404 /1.4435, 1.4301 /1.4307, 1.4462
Chemical Composition Chart
| Grade | C | Si | Mn | P | S | Cr | Ni | Mo | N | ||||
| %max | %max | %max | %max | %max | %min | %max | %min | %max | %min | %max | %min | %max | |
| TP304 | 0.08 | 1.00 | 2.00 | 0.045 | 0.03 | 18.0 | 20.0 | 8.0 | 11.0 | ||||
| TP304L | 0.035 | 1.00 | 2.00 | 0.045 | 0.03 | 18.0 | 20.0 | 8.0 | 13.0 | ||||
| TP316 | 0.08 | 1.00 | 2.00 | 0.045 | 0.03 | 16.0 | 18.0 | 10.0 | 14.0 | 2.0 | 3.0 | ||
| TP316L | 0.035 | 1.00 | 2.00 | 0.045 | 0.03 | 16.0 | 18.0 | 10.0 | 14.0 | 2.0 | 3.0 | ||
| S31803 | 0.03 | 1.00 | 2.00 | 0.03 | 0.02 | 21.0 | 23.0 | 4.5 | 6.5 | 2.5 | 3.5 | 0.08 | 0.2 |
Electro-polished tubes & pipes surface condition
Every EP stainless steel tubing is cleaned, dried with super smoothness and cleanness.
| Surface finishing | Inner Surface Roughness | Outer Surface Roughness |
| ElectroPolished (EP) | EP SS tubing with Ra 0.25μm (10Ra) Max. | Ra 0.8μm max or upon request |
Size Range of Electro-polished tubing
As the professional electropolished stainless steel tubing manufacturer & supplier, our factory produces EP stainless steel tubing with size ranges as below.
- Metric sizes: Outer diameter (OD) 5 mm to 100 mm; Wall thickness (WT) 0.3 mm to 10 mm;
- Imperial sizes: O.D 1/4″ to 4″
Normally, our factory supplies EP tubing with fixed length of 6 meters or 20 feet, and we can produce elector-polishing tubes with max length of 10 meters.
EP tubing/Electropolished stainless steel tubes & pipes cleaning & packing
Following electropolishing, the EP tubing will be water-rinsed, then further passivated in hot nitric acid. This additional passivation is necessary to remove any residual nickel sulfite and to improve the surface ratio of chromium to iron. Following passivation, the EP tubes are rinsed with process water, placed in hot deionized water, dried, and packaged. If clean room packaging is required the tubes are further rinsed in deionized water until a specified conductivity is met, then dried with hot nitrogen gas before packaging.
For EP (electro-polished) stainless steel tubing, each tube will be capped in the ends with polyethylene caps, and every tube will be packed in double polyethylene bags.
Applications of Electro-polished tubing, EP tubes& EP pipes
EP /Electropolished Stainless steel tubing and pipes are widely used in applications where high cleanness, high smoothness, high purity and high performance are required.
Electropolished tubing is specified for so many applications because of:
Surface smoothness, with fewer sites for trapping impurities. For the pharmaceutical industry this means a purer product without danger of bacteria growing in surface defects; the semiconductor industry is extremely sensitive to “killer particles” — small pieces of debris that break free from a pit or crevice and lodge on wafers before vapor deposition, resulting in defective chips.
Easy characterization of surface defects that would otherwise be masked in the maze of surface anomalies found in more common materials.
Here below is a list of the typical applications of the EP tubing.
- Electropolishing tubes for semiconductor wafer processing and medical industries
- High purity liquid convey or high purity gas convey
- Clean gas supply system construction
- Laboratory gas convey
- Size Exclusion Chromatography
- Affinity Chromatography
- Reverse Phase Chromatography
- Biotechnology
- Pharmaceutical instrumentation
- Hydrophobic Interaction Chromatography
- Ion Exchange Chromatography
- Fine chemical industry
Electropolished stainless steel tube fittings
Using our own stainless steel tubing as the mother tube, our factory can also supplies a wide range of electro polished stainless steel fittings. And our electropolished stainless steel fittings are widely used as high purity & UHP(Ultra-high purity) fittings.
Questions & Answers
What is Electropolished stainless steel tubing & electro-polishing?
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What is electro-polished (EP) stainless steel tubing?
- Electro-polished stainless steel tubing is the stainless steel seamless tubing or welded tubing that is polished on the inner diameter with the method of electro-polishing
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What is electro-polishing?
Electropolishing is an electrochemical finishing process that removes a thin layer of material from a metal part, typically stainless steel or similar alloys. The process leaves a shiny, smooth, ultra-clean surface finish.
What are the advantages of electro-polishing & EP tubing?
- The pharmaceutical and semiconductor industries require large volumes of inner surface electropolished stainless steel tubing. In both cases, Type 316L stainless steel is the alloy of choice. 6% molybdenum stainless steel alloys are occasionally used; alloys C-22 and C-276 are important to semiconductor manufacturers, especially when hydrochloric acid gas is used as an etchant. Electropolished tubes are specified for so many applications for the reason of:
- The surface is ultra-smooth and there are few impurity capture points. For the pharmaceutical industry, this means purer products without the danger of bacteria growing in surface defects;
- the semiconductor industry is extremely sensitive to “killer particles” – small fragments that break free from pits or crevices before vapor deposition and stay on the wafer, resulting in defective chips.
- Easily characterize surface defects that would otherwise be masked in the labyrinth of surface anomalies found in more common materials.
- Provides highest corrosion resistance:
Unlike passivation, electropolishing can be performed on all grades of stainless steel and results in better corrosion resistance of various stainless steel parts than passivation alone – electropolished parts are 30 times more resistant to corrosion than passivated parts.
Electropolishing preferentially dissolves free iron, inclusions, and embedded particles from the surface of the work-piece. This process improves the near-surface chemistry of the material and promotes the formation of an improved corrosion resistant surface layer. - Ultra-High Purity
- Highest surface smoothness