Compliance Requirements under the Rules

1. Certificate of Control (Rule 13(1))

Whenever any pressure vessel is manufactured, its design, drawings, and calculations including pressure, material, support, etc. shall be submitted to the Chief Controller or recognized inspector / competent person. Certificate of Control is issued once its design is approved.

2. Design, construction and testing of pressure vessels as per approved safety standards (Rule 13(2))

Every pressure vessel must be designed, built & tested as per the recognized standard/codes such as IS 2825, IS 2825; ASME Section VIII Division 1 or Division 2, PD5500, EN 13458, EN 13530, AD: 2000 code as amended from time to time, or such other standard/code accepted by the Chief Controller.

3. Compliance with design pressure limits and wind/seismic load requirements for vessels (Rule 14)

Allowable Design pressure of a vessel:

• • Vessel for the storage of liquefiable gases: Vapour pressure of 55°C
  • Vessel for the storage of permanent gases: Developed pressure of 55°C
  • Wind load, Seismic loads shall also be considered for vertical cylindrical vessels and Horton spheres

Static head (higher of the water column or the compressed gas column) shall also be considered for static pressure vessels.

4. Refrigerated vessels to meet Rule-13 design code and ensure vapour pressure within limit (Rule 15(1))

Refrigerated Vessels storing low-temperature gases must be designed according to the design code mentioned in Rule-13.
Capacity of refrigeration system shall be adequate to maintain the gas in the vessel at a temperature so that its vapour pressure does not exceed the design pressure.

5. Design requirements for gases at low temperature in Insulated vessels (Rule 15(2))

The shell of the vessel and its manhole nozzle shall be insulated with a material approved by the Chief Controller. The insulation shall be of sufficient thickness so that the thermal conductance at 15°C shall not exceed the limit prescribed by the Chief Controller.

6. Design requirements for gases at low temperature in Cryogenic pressure vessels (Rule 15(3))

Vessel design should be as prescribed in rules, for eg:

1. 1. Inner vessel, piping, and fittings must be made from suitable material
   2. Outer vessel must be made of steel (min. 3 mm thick) or aluminium (min. 4 mm thick), etc.

Design service temperature of the cryogenic pressure vessels should not be higher than normal boiling point of the cryogenic liquid.
Inner supports between the inner vessel and the outer vessel should be of non-inflammable materials and capable of supporting the inner vessel together with the maximum allowable cryogenic liquid.
Cryogenic pressure vessels meant for transport purpose should be able to withstand maximum static loading individually as specified.
Air in the annular space between the inner and outer vessel shall be evacuated and filled with suitable insulating material compatible.

7. Filling Capacity and Pressure Limit (Rule 16)

Capacity of the refrigeration system shall be adequate to maintain the gas in the vessel at a temperature so that its vapour pressure does not exceed the design pressure of the vessel and shall also remain below the pressure-setting of the relief valve. The pressure vessel approved for filling with a particular gas shall not be used for filling with any other gas unless specific approval and amendment of license is obtained from the Chief Controller or Controller.

8. Marking and Painting of Pressure Vessel (Rule 17)

Every vessel shall have a metal plate permanently fixed showing particulars specified under Rule-17 of SPMV Rules, 2016 and visible from ground level, including manufacturer’s name, approval number, identification number, code, design pressure, test details, capacity, gas name, and design temperature. Above-ground vessels shall be adequately painted to prevent corrosion and shall have a reflecting surface

9. Vessel Fittings and Connections (Rule 18)

Each vessel must be equipped with mandatory fittings including pressure relief valve, drain, content/level gauge, pressure gauge, and temperature measurement provision. All vessel connections must be designed and installed as per prescribed rules.

Vessel Fittings and Connections shall be designed in accordance with Rule-13 of SPMV Rules, 2016.

10. Periodic Hydraulic testing of pressure vessels (Rule 19(1) & 19(2))

Hydraulic Test shall be conducted by a competent person at a pressure marked on the vessel within every 5 years after the date of first test, for all pressure vessels with water capacity up to 100 KL.

Where hydraulic testing is not feasible, pneumatic testing with non-destructive tests may be permitted by the Chief Controller subject to safety precautions. Online certificate of test shall be issued.

11. Periodic Hydraulic and Non-Destructive testing of pressure vessels (Rule 19(1) & 19(2))

Hydraulic and Non-Destructive Tests shall be conducted within every 5 years after the first test for pressure vessels having water capacity greater than 100 KL.

Where required, pneumatic testing with NDT may be permitted and online certificate of test shall be issued.

12. Periodic Hydraulic and Non-Destructive testing for vessels containing corrosive or toxic gases (Rule 19(1), 19(2) & 19(3))

Hydraulic and Non-Destructive Tests shall be conducted within every 5 years for pressure vessels of capacity greater than 100 KL containing corrosive or toxic gases.

Alternate testing methods may be permitted by the Chief Controller with issuance of online certificate of test.

13. Periodic testing of mounded and underground pressure vessels (Rule 19(4))

Mounded and underground vessels shall be periodically inspected as specified in Schedule III.

In case of major repair, vessels shall undergo NDT and hydro testing as per original code and be treated as a new vessel for inspection purposes.

14. Periodic Testing for Ammonia Horton Sphere (Rule 19(5))

Testing shall be conducted as follows:

• • First test after 2 years of installation (Non-Destructive Testing)
  • Second test after 3 years (Non-Destructive and Hydro Testing)
  • Subsequent tests at 5-year intervals

In case of major repair, testing shall be carried out as per original design code and procedure approved by the Chief Controller.

15. Precautions while Periodic Testing of Pressure Vessel (Rule 20)

Before periodic testing, the pressure vessel must be thoroughly cleaned.
Evacuation or degassing of transport vessels used for flammable or toxic gases shall be carried out at licensed degassing stations or premises.

Any vessel failing the hydraulic test or found unsafe shall be destroyed or rendered unsuitable under intimation to the Chief Controller.