Services
Cylinder Hydrotesting
Ensuring Strength, Safety & Regulatory Compliance of Gas Cylinders
Overview
Cylinders hydrotesting, commonly referred to as Hydrostatic Stretch Testing, is a process we carry out at Bhagyalaxmi Gas Solutions on all high-pressure gas cylinders (except for acetylene) as part of our commitment to provide a safe operating environment for the use of Hydrogen and all other industrial gases. The purpose of Hydrotesting is to determine if the cylinder is structurally sound, elastic in nature, and leak proof; therefore, the Registry must maintain compliance with all applicable legal regulations.
Gas cylinders are subjected to repeated cycles of pressurization and depressurization and eventually this can lead to material failure and an unsafe condition. Through periodic Hydrotesting a company can assure that the cylinders will hold up to their stated test pressure and return to their original dimensions and state of elasticity within acceptable limits.
Why Hydrotesting is Mandatory
According to Rule 35 of the Gas Cylinder Rules, 2016, along with guidelines provided by the Petroleum & Explosives Safety Organisation (PESO), all high-pressure seamless gas cylinders shall be tested periodically (hydrostatically) at least every 5 years or sooner if the condition of the cylinder does not warrant this testing sooner via a visual inspection.
All cylinders will be hydrotested at a test pressure of either 1.5x or 1.66x the cylinder’s working pressure. The test pressure depends on the manufacturing standard and manufacturing material of the gas cylinder (cylinder’s MOC). Hydrotesting is done to provide an evaluation of:
- Elastic Expansion of the Cylinder
- No Permanent Deformation
- Structural Strength under Pressure
- No Internal or external defects
- Meets BIS & PESO Regulations
If the cylinder does not return to its original dimensions after removing the pressure applied to it, it is considered unsafe and should not be used.
Cylinders Covered Under Our Hydrotesting Services
Hydrostatic testing is offered for numerous types of cylinders, such as:
- Seamless cylinders that hold hydrogen.
- Cylinders of Industrial Gases (Oxygen, Nitrogen, Argon, CO2, Helium).
- Calibration Gas Cylinders/Speciality Gases.
- Single cylinders, bundles and cascades.
All cylinders received will be checked for proper identification markings, tare weight, valve condition and compliance due date before being tested.
How We Hydrotest Your Cylinders
All testing is performed strictly in accordance with applicable BIS standards, including:
- IS 5844 – Hydrostatic stretch testing
- IS 8451:2018 – Inspection and testing procedures
- IS 15975 – Periodicity and inspection guidelines
Being a PESO-recognized test facility, we follow the same rigorous safety and quality practices used in our own hydrogen operations.
1. Preparatory Inspection
- Degassing of cylinders
- Valve removal (if required)
- Internal and external cleaning
- Visual inspection using a borescope
- Verification of markings and tare weight
2. Hydrostatic or Hydrostatic-Stretch Test
Testing is conducted using:
- Water Jacket Method (for high-pressure seamless cylinders)
- Non-Jacket Method (where applicable)
Parameters measured include:
- Total expansion
- Permanent vs elastic expansion
- Pressure holding time
Acceptance criteria strictly follow BIS specifications.
3. Post-Test Process
- Internal drying using a heater blower
- Final visual inspection
- Classification as Pass / Repair / Condemn
- Updating of cylinder markings
- Issuance of hydrotest certificates and test rings
What You Receive
- Individual hydrotest certificate for each cylinder
- Consolidated test result summary
- Updated markings and test rings
- Validity of test as per Rule 35 and IS 15975 (typically 5 years)
Who Uses this Service?
- Industrial gas distributors
- Hydrogen generation and storage plants
- Pharmaceutical and chemical manufacturers
- Laboratories, R&D centres, and pilot plants
- EPC contractors managing cylinder fleets
Industries We Serve
Why BLGS?
Hydrogen-focused procedures and careful cylinder handling
Execution and records aligned to GCR-2016 and BIS codes
Efficient lot throughput to minimize cylinder downtime
Partner for Cutting-Edge Hydrogen Solutions
Let’s build safe, reliable, and future-ready hydrogen systems together — engineered for performance, tested for safety, and built to last.