Pressure vessels are critical equipment used for storing and transporting compressed gases, liquefied gases and certain cryogenic liquids. Because these vessels operate under pressure and may contain hazardous substances, their design, fabrication, testing, installation and operation are subject to specific safety requirements in India — and, as with gas cylinders, not all under a single approval.
The Petroleum and Explosives Safety Organisation (PESO) administers the Static and Mobile Pressure Vessels (Unfired) Rules, 2016, commonly known as the SMPV(U) Rules, 2016, and provides a dedicated procedure for approvals and licences under these rules. For manufacturers, importers, industrial establishments and operators handling pressure vessels, understanding the PESO Approval for Pressure Vessels that actually applies is essential before fabrication, import, installation or operation.
PESO Approval for Pressure Vessels refers to the regulatory approval process for pressure vessels covered by the SMPV(U) Rules, 2016. It can involve fabrication workshop approval, pressure-vessel design/type approval, import approval (Form AS-3), a licence for storage of compressed gas (Form AS-1), a licence for transportation of compressed gas (Form AS-2), inspection, testing, and periodic revalidation. There is no single certificate — the applicable approval depends on the type of vessel, gas, capacity, intended use and activity.
📑 Quick Navigation
- What Is PESO Approval for Pressure Vessels?
- Which Pressure Vessels Come Under PESO?
- Static vs Mobile Pressure Vessels
- Fabrication Workshop Approval
- Design Approval
- Approval for Imported Pressure Vessels
- Licence for Storage of Compressed Gas
- Approval Process
- Documents Required
- Role of the Inspector
- Certificate of Control & Testing
- Installation & Periodic Testing
- Modification of Pressure Vessels
- Safety Requirements
- Recent PESO Developments
- Common Mistakes
- How Rego Services Can Help
- Frequently Asked Questions
What Is PESO Approval for Pressure Vessels?
PESO Approval for Pressure Vessels refers to the regulatory approval process applicable to pressure vessels covered by the SMPV(U) Rules, 2016. The process can involve different approvals depending on the activity, including:
For workshops manufacturing pressure vessels, vaporizers and fittings.
For the specific pressure vessel design proposed for fabrication.
For pressure vessels brought into India, before commercial import.
For installations storing compressed gas in a vessel or vessels.
For mobile vessels transporting compressed gas in a vehicle.
Ongoing safety certification and periodic testing requirements.
PESO pressure-vessel compliance is not necessarily one single certificate. The applicable approval depends on the type of vessel, gas, capacity, intended use and activity.
Which Pressure Vessels Come Under PESO?
The SMPV(U) Rules, 2016 establish requirements for covered static and mobile pressure vessels used for compressed gases and related applications. PESO's official SOP provides procedures for pressure vessels, vaporizers and fittings under this framework. Pressure-vessel applications can include equipment used for LPG, LNG, CNG-related applications, industrial gases, flammable gases, toxic gases, non-flammable gases, cryogenic liquids, carbon dioxide, and other compressed gases covered by the rules.
The exact requirements must be determined according to the substance and the particular pressure-vessel installation.
Static and Mobile Pressure Vessels
- Installed at a fixed location, generally used for storing compressed or liquefied gases
- Examples: bulk LPG storage vessels, LNG storage vessels, industrial gas storage vessels, CO₂ storage vessels, cryogenic storage tanks
- Applicable PESO approval or licence must be assessed before operation
- Designed for transportation of compressed or liquefied gases
- Includes certain gas tankers and transport vessels
- Separate provisions apply for transportation and related safety certification
- PESO's forms list includes Form AS-2 for grant or amendment of a licence to transport compressed gas in a vehicle
PESO Approval for Pressure-Vessel Fabrication Workshops
One of the important stages of pressure-vessel compliance is approval of the fabrication workshop. PESO's current SMPV(U) SOP states that workshops undertaking fabrication of pressure vessels, vaporizers and fittings are required to be approved by PESO. The process involves submission of the required documents followed by inspection of the premises.
During inspection, PESO assesses the workshop's capabilities, including:
- Technical manpower
- Design capability
- Fabrication capability
- Quality-control arrangements
- Machinery, tools and equipment
- Testing facilities
- Fabrication space
If the inspection report is satisfactory, the workshop may be approved for pressure-vessel fabrication. PESO also maintains an official list of approved shops for manufacture of pressure vessels under the SMPV(U) Rules, 2016.
Pressure-Vessel Design Approval
Workshop approval is only one part of the process. After approval of the fabrication workshop, the fabricator must seek type approval or design approval for the pressure vessel, vaporizer or fitting proposed for fabrication. The documentation can include fabrication drawings, mounting drawings, design calculations, a design appraisal certificate, Inspector-vetted drawings, safety-relief-valve documentation, and other technical documents required for the particular application.
The SMPV(U) Rules specifically provide for submission of design calculations and fabrication drawings duly vetted by an Inspector for pressure-vessel design approval.
Not sure whether your project needs workshop approval, design approval, or both?
Talk to a Compliance ProfessionalPESO Approval for Imported Pressure Vessels
Businesses importing pressure vessels into India should verify the applicable PESO approval requirements before import. The SMPV(U) Rules state that a person cannot import a covered pressure vessel without prior approval from the Chief Controller. The rules provide for an application in Form AS-3, together with manufacturer test and inspection documentation, inspection certification from the country of origin, and design information.
Importers should complete the applicable approval process before arranging commercial importation.
PESO Licence for Storage of Compressed Gas
When a pressure vessel is installed for storage of compressed gas, a separate licensing requirement can apply. PESO's official forms list identifies Form AS-1 as the application for the grant, amendment or renewal of a licence to store compressed gas in a vessel or vessels. This is particularly relevant to industrial facilities using bulk storage systems. The exact licence requirements depend on the gas, vessel configuration, capacity and installation.
| Form | Purpose |
|---|---|
| Form AS-1 | Grant, amendment or renewal of a licence to store compressed gas in a vessel or vessels |
| Form AS-2 | Grant or amendment of a licence to transport compressed gas in a vehicle |
| Form AS-3 | Import approval for a covered pressure vessel, with manufacturer test/inspection documentation and design information |
PESO Pressure-Vessel Approval Process
The process can differ depending on whether the applicant is a manufacturer, importer, storage-facility operator or transporter.
Determine the gas or substance to be stored, gas classification, vessel type, capacity, operating pressure, intended use, and whether the application is static or mobile.
Determine whether the requirement involves fabrication workshop approval, design approval, import approval, storage licence, transportation licence, testing/revalidation, or safety certification.
Where fabrication is involved, confirm the proposed workshop is approved under the applicable PESO framework, using PESO's published list of approved fabricators.
Design calculations, fabrication drawings, mounting drawings, technical specifications, design appraisal documents, safety-fitting details, material information, and testing documentation.
The applicable drawings and calculations are reviewed and vetted according to the SMPV(U) procedure.
The vessel is fabricated according to the approved design and applicable fabrication code, with required inspections during the fabrication process.
The completed pressure vessel undergoes applicable inspection and testing.
Where applicable, the completed vessel and installation are submitted for the relevant PESO licence or safety certification.
After approval, continue to comply with applicable inspection, testing, safety and renewal requirements.
Documents Required for PESO Pressure Vessel Approval
The exact document checklist depends on the application. Typical technical and regulatory documents may include:
- Application form and company/applicant details
- Pressure-vessel specifications
- Design calculations
- Fabrication drawings and mounting drawings
- Design appraisal certificate
- Inspector-vetted documents
- Material certificates and test reports
- Safety-relief-valve information
- Inspection reports
- Certificate of Control, where applicable
- Site/layout drawings
- Gas details
- Land or premises documents
PESO's current SOP should be used to confirm the final document requirements for the particular pressure-vessel application.
Need help preparing your pressure vessel approval application?
Contact Rego ServicesRole of the Inspector in Pressure-Vessel Approval
Inspection is an important part of pressure-vessel compliance. The SMPV(U) framework provides for recognised Inspectors and competent persons for specified functions. Inspection can cover design documentation, fabrication stages, testing and certification. The design calculations and fabrication drawings submitted for pressure-vessel approval are required to be duly vetted by an Inspector under the applicable procedure — an additional technical verification layer between the proposed design and the completed vessel.
Certificate of Control and Testing
Pressure-vessel fabrication requires appropriate documentation demonstrating that the vessel has been fabricated and tested according to the applicable requirements. PESO's SMPV(U) procedure includes the Certificate of Control and hydro-test documentation among the documents relevant to revalidation cases. Businesses should maintain complete records relating to material traceability, fabrication, inspection, hydro testing, safety-relief devices, repairs, modifications, previous approvals, and periodic testing.
PESO Approval for Pressure Vessel Installation & Periodic Testing
Obtaining approval for a pressure vessel does not necessarily complete the compliance process — the installation must also satisfy applicable safety requirements. PESO's SMPV(U) framework provides for safety certification and periodic testing functions through recognised competent persons.
Depending on the vessel and applicable rules, periodic inspection and testing may be required. Businesses should maintain a schedule covering:
Track scheduled inspection and hydro-test dates against regulatory requirements.
Hydro-test records, safety-relief-valve testing, and applicable certificates.
Document any repairs or modifications made to the vessel over its service life.
Track renewal deadlines to avoid a lapse in the applicable licence.
Failure to maintain testing and inspection records can create compliance issues during subsequent regulatory review.
PESO Approval for Pressure Vessel Modification
An approved pressure vessel should not be modified without first determining whether PESO approval is required. Modifications can include changes to vessel components, nozzles, connections, safety fittings, mounting arrangements, structural components, pressure-related equipment, or internal/external configuration. PESO maintains specific regulatory information concerning modifications and repairs of mobile pressure vessels licensed under the SMPV(U) framework. The proposed modification should be assessed before fabrication or repair work begins.
Important Safety Requirements
Pressure vessels must be equipped with appropriate safety systems based on the gas and application. Depending on the vessel, safety provisions can involve safety relief valves, pressure gauges, temperature indicators, level-measuring devices, excess-flow protection, isolation arrangements, emergency shutdown systems, fire protection, and appropriate electrical safety measures. The precise requirements depend on the gas, vessel and installation and should be established from the applicable SMPV(U) requirements.
Recent PESO Developments for Pressure Vessels
PESO continues to update its procedures and online services. Its current circulars include updates concerning modifications and repairs in mobile pressure vessels, recognition and competency matters under the SMPV(U) Rules, and other pressure-vessel-related requirements. PESO also maintains online information about approved pressure-vessel fabrication shops, recognised competent persons and inspectors, and other entities associated with SMPV(U) compliance.
Areas of Active PESO Regulatory Activity
- Updates concerning modifications and repairs in mobile pressure vessels licensed under the SMPV(U) framework
- Recognition and competency matters for Inspectors and competent persons under the SMPV(U) Rules
- Published lists of approved pressure-vessel fabrication shops
Businesses should verify the current procedure before starting a new pressure-vessel approval or modification project directly against the official PESO portal.
Common Mistakes in PESO Pressure Vessel Approval
Where PESO workshop approval is applicable, the fabricator should be verified against the official approved-fabricator information.
Fabrication should follow the prescribed approval and inspection sequence.
Design calculations must be prepared according to the applicable fabrication/design code and vetted as required.
Fabrication and mounting drawings should accurately reflect the proposed pressure vessel.
Missing inspection certificates, material documents or test records can cause regulatory queries.
Imported pressure vessels may require prior PESO approval before commercial import.
Changes to an approved pressure vessel should be assessed before modification.
Pressure-vessel compliance is an ongoing responsibility that should include appropriate inspection and testing.
How Rego Services Can Help With PESO Pressure Vessel Approval
Obtaining PESO Approval for Pressure Vessels can involve multiple technical and regulatory stages. Rego Services can assist businesses with:
- Identifying the applicable PESO approval — workshop, design, import (Form AS-3), storage (Form AS-1), or transportation (Form AS-2)
- Understanding SMPV(U) Rules, 2016 requirements
- Reviewing pressure-vessel specifications
- Assessing the applicable licence category
- Preparing application documentation
- Supporting technical drawings and design-related documentation
- Supporting fabrication-workshop approval documentation
- Preparing import-approval documentation, where applicable
- Supporting PESO application submission
- Coordinating inspection-related documentation
- Responding to regulatory queries
- Supporting renewal, amendment and modification requirements
The exact compliance requirements depend on the gas, vessel type, capacity, location and intended application — this is professional assistance throughout the process, not a guarantee of approval, which remains at PESO's discretion.
Frequently Asked Questions
What is PESO Approval for Pressure Vessels?
It is the applicable regulatory approval, licence or certification process administered by PESO for pressure vessels covered by the SMPV(U) Rules, 2016.
Which rules apply to pressure vessels in India?
The primary PESO framework is the Static and Mobile Pressure Vessels (Unfired) Rules, 2016. PESO publishes the rules and a dedicated SOP for approvals and licences under this framework.
Does PESO approve pressure-vessel fabrication workshops?
Yes. PESO's SMPV(U) procedure provides for approval of workshops undertaking fabrication of pressure vessels, vaporizers and fittings. The workshop is subject to document review and inspection.
Is pressure-vessel design approval required?
For covered pressure vessels fabricated under the applicable SMPV(U) process, the fabricator must seek the required type or design approval after workshop approval.
Is PESO approval required for imported pressure vessels?
The SMPV(U) Rules state that covered pressure vessels cannot be imported without prior approval from the Chief Controller, subject to the applicable provisions.
Which form is used for storage of compressed gas in pressure vessels?
PESO's forms list identifies Form AS-1 for application for the grant, amendment or renewal of a licence to store compressed gas in a vessel or vessels.
Which form is used for transportation of compressed gas?
PESO identifies Form AS-2 for the grant or amendment of a licence to transport compressed gas in a vehicle.
Does PESO approval apply to LPG pressure vessels?
Yes, where the LPG pressure-vessel installation falls within the scope of the SMPV(U) Rules and applicable licensing requirements.
Does PESO approval apply to LNG and cryogenic pressure vessels?
Covered LNG and cryogenic pressure-vessel applications can fall under the SMPV(U) framework. The exact approval depends on the vessel, substance and intended application.
✓ Key Takeaways
- PESO Approval for Pressure Vessels is not one certificate — it spans fabrication workshop approval, design approval, import, storage, and transportation licensing under the SMPV(U) Rules, 2016
- Fabrication workshops must be PESO-approved before undertaking pressure-vessel manufacture, based on technical, quality-control, and testing capability
- Each vessel design requires type/design approval, with fabrication drawings and design calculations vetted by an Inspector
- Form AS-1 covers storage licensing, Form AS-2 covers transportation licensing, and Form AS-3 covers import approval
- The framework covers both static (fixed bulk storage) and mobile (transport) pressure vessels
- Compliance continues after approval through periodic testing, hydro-testing, and Certificate of Control documentation
- Modifications to an approved vessel should be assessed for regulatory review before fabrication or repair work begins
Conclusion
PESO Approval for Pressure Vessels is an important regulatory requirement for businesses involved in the manufacture, import, storage, transportation, installation or operation of covered pressure vessels in India. The approval process can involve fabrication-workshop approval, design approval, technical drawings, design calculations, inspection, fabrication controls, testing, certification and installation licensing. The correct compliance route depends on the gas, pressure vessel type, capacity, application and facility — Form AS-1 applies to storage, Form AS-2 to transportation, and Form AS-3 to import.
Businesses should determine the applicable requirements before fabrication, import or installation rather than treating PESO pressure-vessel approval as a one-step registration. Contact Rego Services for PESO Compliance Assistance to discuss your specific pressure vessel requirement.
Rego Services Compliance Team
August 2026