IS 9537:1981 Part 2 is the Indian Standard (BIS) for conduits for electrical installations - part 2: flexible steel conduits. This standard specifies the requirements for plain (uncovered), flexible steel conduits intended for the protection of cables in electrical installations. It covers material, construction, dimensions, mechanical strength (compression and flexing), and testing procedures.
Specifies requirements for flexible steel conduits used for the protection of electrical wiring installations.
Overview
- Status
- Current
- Usage level
- Frequently Used
- Domain
- MEP — Electrical Installations
- Type
- Specification
- Amendments
- Amendment 1 (Aug 1986)
Also on InfraLens for IS 9537
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! CRITICAL: This standard has been superseded and withdrawn. For all new projects, refer to IS 3480:2023 'Flexible Steel Conduits for Cable Management'.
! Select the conduit classification (Light, Medium, etc.) based on the anticipated mechanical stress and protection level required for the installation area.
! Ensure proper termination using glands and accessories to maintain mechanical integrity and electrical continuity of the system.
Frequently referenced clauses
Updates & Amendments1 amendment
Consolidated list per BIS. For the text of each amendment, refer to the BIS portal link above.
steelconduit
International Equivalents
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International Comparison — Coming Soon
We're adding equivalent international standards for this code.
Key Values6
Quick Reference Values
Range of nominal sizes16 mm to 63 mm
Minimum compression force (Class 2 Light)320 N
Minimum compression force (Class 3 Medium)750 N
Number of cycles for flexing test5000 cycles
Tolerance on internal diameter (for 20mm size)+0.4 / -0.0 mm
Maximum external diameter (for 20mm size)22.5 mm
Tables & Referenced Sections
Key Tables
Table 1 - Dimensions of Flexible Conduits
Table 2 - Requirements for Mechanical Properties
Key Clauses
Clause 6 - Dimensions
Clause 7 - Construction
Clause 8 - Mechanical Properties
Clause 10 - Marking
Appendix A - Test for Resistance to Flexing
Appendix B - Compression Test
Frequently Asked Questions4
Is this code still valid for use?+
No, IS 9537 (Part 2) has been officially replaced by IS 3480:2023. This code should only be used for reference on older installations.
What are the standard sizes covered in this code?+
The code specifies nominal sizes ranging from 16 mm to 63 mm (Table 1).
What is the main test to check the durability of the flexible conduit?+
The resistance to flexing test (Appendix A), which requires the conduit to withstand 5000 flexing cycles without breaking or uncoiling.
How is the compression strength classified?+
It's classified based on the force it can withstand. For example, 'Class 2 Light' must resist 320 N and 'Class 3 Medium' must resist 750 N (Table 2).
QA/QC Inspection Templates
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QA/QC templates coming soon for this code.