SS Electropolished Pipe Supplier India — 316L EP, ASME BPE

Electropolished pipe is stainless steel tube that has undergone an electrochemical surface finishing process. The pipe is immersed in a phosphoric-sulphuric acid electrolyte and subjected to a direct current, causing controlled dissolution of surface peaks. This produces an ultra-smooth, microscopically flat surface with Ra values below 0.4 micrometres (typically 0.2-0.4um). The process also enriches the chromium-to-iron ratio on the surface, creating a superior passive layer that resists corrosion and particle adhesion.

We supply EP pipe in two standard Ra levels: Ra less than or equal to 0.4 micrometres (standard pharmaceutical grade per ASME BPE SF-3) and Ra less than or equal to 0.25 micrometres (ultra-high-purity grade per ASME BPE SF-4 for semiconductor applications). Surface roughness is measured using a calibrated profilometer at multiple locations along the tube length and at both ends. Each tube is supplied with an individual Ra measurement report showing readings at 0-degree, 90-degree, 180-degree and 270-degree positions.

Our 316L EP pipe complies with ASTM A270, ASME BPE (BioProcessing Equipment standard), FDA 21 CFR, EU GMP Annex 1, and ISPE Baseline Guide for Water and Steam Systems. The pipe meets 3-A Sanitary Standards for cleanability. Documentation includes material certificates, EP process certificates, Ra measurement reports, borescope images, passivation verification per ASTM A967, and rouge-free test reports. We can supply validation packages for pharma project qualification (IQ/OQ documentation).

Orbital automatic TIG welding is the preferred joining method for EP pipe systems because it produces consistent, repeatable welds with minimal heat-affected zone and no crevices. Orbital welds maintain the internal surface quality of the EP pipe and can be borescope-inspected to ASME BPE weld acceptance criteria. For connections to equipment, tri-clamp (sanitary clamp) fittings are used. We supply EP pipe with squared, deburred ends prepared specifically for orbital welding to ensure proper fit-up and penetration.

Yes. We supply complete electropolished piping systems including straight tubes, 90-degree and 45-degree elbows, tees, reducers, tri-clamp ferrules, gaskets, clamps, sample valves, diaphragm valves, and tank outlets — all electropolished to matching Ra values. This ensures consistent surface quality throughout the entire system. We can also provide pre-fabricated pipe spools (orbital welded in our clean room) ready for site installation, significantly reducing field welding and validation time.

Passivation is a chemical treatment (typically with citric or nitric acid per ASTM A967) that removes free iron from the surface and enhances the protective chromium oxide layer. After electropolishing, passivation further improves the corrosion resistance of the pipe surface and reduces the risk of rouge formation in high-purity water systems. All our EP pipe is passivated after electropolishing and verified by water-break testing and ferroxyl testing to confirm a uniform, iron-free passive surface.