SS Welded Pipes & Tubes

BIS ISI Certification for Stainless Steel Welded Pipes and Tubes for General Service in India: Complete Compliance Guide

Stainless steel welded pipes and tubes for general service applications require mandatory BIS ISI mark certification under the Quality Control Order framework in India. This guide covers IS standards, weld quality testing, and the FMCS licence process.

Published: May 2026 Reading Time: 8 min Category: Product Compliance / Steel and Metal Products Certification Type: BIS ISI Mark (FMCS)

BIS ISI Certification for Stainless Steel Welded Pipes and Tubes for General Service in India falls under mandatory BIS ISI Mark certification in India under the applicable Quality Control Order (QCO). Unlike the BIS CRS scheme, the ISI Mark (FMCS licence) requires a factory audit by a BIS officer, in-plant quality management verification, and ongoing product testing through periodic surveillance — in addition to type-testing at a BIS-approved laboratory. Non-compliance attracts market withdrawal, seizure of goods, and prosecution under the BIS Act 2016.

This guide covers the applicable Indian Standards, mandatory testing requirements, the step-by-step FMCS licence process, documentary requirements, and the most critical compliance pitfalls for this product category in 2026.

📜 Applicable Indian Standards

The following Indian Standards and Quality Control Orders apply to this product category:

📌 Welded stainless steel pipes and tubes have an additional weld seam quality requirement compared to seamless products. BIS testing for welded tubes specifically evaluates weld bead geometry, weld penetration, heat-affected zone hardness, and the results of the flattening test — all of which are unique to the welded tube manufacturing process and are not required for seamless products.

🔬 Mandatory Tests and Assessments

BIS-approved laboratories and BIS officers evaluate the following key areas during type-testing and factory audit for this product category:

Chemical Composition

Chromium, nickel, molybdenum, carbon, and manganese content verification against IS 6913 / IS 2635 grade specifications.

Weld Quality

Weld bead geometry, penetration assessment, heat-affected zone hardness, and visual examination of the weld seam.

Mechanical and Flattening Tests

Tensile strength, yield strength, elongation, and mandatory flattening test on welded tube samples to verify weld ductility.

Hydrostatic and NDT

Hydrostatic pressure test or eddy-current/ultrasonic non-destructive testing of the weld seam on 100% of production.

📋 Step-by-Step BIS ISI Mark (FMCS) Licence Process

  1. IS Standard and Grade IdentificationConfirm applicable IS standard (IS 6913 or IS 2635) and identify the grades to be covered. Verify QCO applicability for the specific tube dimensions and grades.
  2. BIS Form V Licence ApplicationSubmit Form V online on BIS Manak Online portal with factory details, production capacity, and list of grades and sizes to be licensed.
  3. Factory Audit by BIS OfficerBIS officer audits the welding plant including welding machine calibration, weld inspection equipment, hydrostatic/NDT testing setup, and process control records.
  4. Sample Testing at BIS-Approved LabOfficer-drawn samples are tested for chemical composition, mechanical properties, flattening test, and weld inspection at a BIS-approved laboratory.
  5. Corrective Action and ComplianceAny audit findings — such as inadequate weld inspection coverage or calibration gaps — must be resolved before licence grant.
  6. FMCS Licence and ISI MarkBIS grants the FMCS licence. The ISI mark is stamped, stencilled, or tagged on each welded tube at the factory.
  7. Annual Renewal and SurveillancePeriodic surveillance audits and product sampling are conducted by BIS. Annual fee payment and compliance documentation renewal are required.

📄 Documents Required

AnnualLicence Renewal
2-4 MonthsTypical Licence Grant
2x/yearBIS Surveillance
Weld Seam NDT Coverage: IS 6913 and IS 2635 require non-destructive testing of the weld seam on 100% of production by eddy-current or ultrasonic methods, or alternatively hydrostatic testing of every tube. In-plant NDT equipment must be calibrated, and NDT records must demonstrate 100% weld-seam coverage. Factories that test only a sample of production — rather than 100% — will fail the BIS audit.

Common Causes of Licence Rejection or Suspension

Common causes of licence rejection include the weld flattening test revealing cracking at the weld seam before the specified flattening distance is achieved, weld seam NDT coverage records showing less than 100% production testing, heat-affected zone hardness exceeding the maximum specified in the standard, chemical composition of the parent strip deviating from the IS grade specification, and hydrostatic test records being incomplete or not traceable to individual tube production records.

🏭 Special Considerations for Importers

Importers of stainless steel welded pipes and tubes must ensure ISI mark compliance under the applicable QCO before customs clearance. Import of non-compliant welded tubes is prohibited under the QCO and is subject to confiscation and penalties at Indian ports. Importers should request certified mill test certificates, weld NDT records, and ISI mark certification from the overseas manufacturer before each shipment.

Stainless Steel Welded Pipe BIS ISI Certification Partner

Global Approbation manages BIS FMCS licence applications for stainless steel welded pipes and tubes — from weld quality testing to ISI mark grant and ongoing surveillance support.

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