OISD 118 Compliance
Audit Checklist (Excel)

OISD 118 (Layout for Oil and Gas Installations) is the Oil Industry Safety Directorate standard governing layout and inter-distance requirements for petroleum installations in India under MoPNG (Ministry of Petroleum and Natural Gas) jurisdiction. It applies to refineries, petrochemical plants, gas processing facilities, LPG bottling plants, oil terminals, and pipeline installations across India. Compliance is mandatory and enforced by PNGRB (Petroleum and Natural Gas Regulatory Board) audits, MoPNG inspections, and statutory licensing under the Petroleum Act 1934 and the Petroleum Rules 2002.

Chapter 3 of OISD 118 is the core inter-distance compliance chapter. It specifies minimum distances between Class A, Class B, and Class C petroleum equipment (Class A is gases at ambient temperature, Class B is liquids with flash point below 23°C, Class C is liquids with flash point between 23°C and 65°C), distances from equipment to plant battery limit, distances from equipment to public roads and residential boundaries, and distances between tanks of different capacities. Chapter 3 inter-distance compliance is the most-audited section of OISD 118 and the most-common non-compliance finding. See the OISD 118 standard reference.

Pathnovo, an engineering document intelligence platform, runs OISD 118 audit by extracting equipment locations and distances from the plot plan, equipment list, and P&IDs, then comparing the actual configuration against the OISD 118 Chapter 3 inter-distance table per equipment class. Non-compliances and partial compliances are flagged with severity, OISD clause reference, and recommended corrective action. Typical audit cycle drops from 4 to 8 weeks manual to 1 week auto-audited. See the OISD 118 compliance workflow.

OISD 118 compliance is HAZOP-aware. Any HAZOP recommendation that affects equipment placement, vessel capacity, hazardous area extent, or layout must update the OISD 118 Chapter 3 inter-distance compliance table. Any Management of Change (MoC) that adds new equipment, increases vessel capacity, or reroutes hazardous lines must run a fresh OISD 118 compliance check before approval. The audit checklist Cross-Reference column ties each finding to the relevant HAZOP action or MoC. See the HAZOP register template and the management of change standard reference.

OISD 118 covers layout and inter-distance requirements (where equipment can be placed). OISD 116 covers fire protection requirements (how equipment must be protected against fire and what firefighting infrastructure is required). Both standards apply to the same petroleum installations and both are audited together during MoPNG and PNGRB inspections. OISD 116 references OISD 118 for hazardous area classification, and OISD 118 references OISD 116 for fire-water demand calculation per area. The OISD audit checklist supports both, with OISD 116 as a sibling template.

MoPNG (Ministry of Petroleum and Natural Gas) audits cover the parent ministry's regulatory scope across upstream, midstream, and downstream petroleum operations. PNGRB (Petroleum and Natural Gas Regulatory Board) audits cover the specific regulatory scope of the PNGRB Act 2006, which is primarily downstream natural gas and petroleum pipeline operations. Refineries and petrochemical plants are audited by MoPNG and state regulators; gas pipelines and city gas distribution networks are audited by PNGRB. Both audit frameworks reference OISD 118 as the layout-compliance baseline.

PESO (Petroleum and Explosives Safety Organisation) licenses storage and handling of petroleum and explosive substances under the Petroleum Act 1934. CCOE (Chief Controller of Explosives) issues operating licenses for tank farms and petroleum storage facilities. OISD 118 layout compliance is a prerequisite for PESO and CCOE licensing: a tank farm cannot get a CCOE license without OISD 118 Chapter 3 inter-distance compliance, and a pressure equipment installation cannot get a PESO license without OISD 118 layout compliance for the surrounding installation. See the PESO compliance workflow and the CCOE compliance workflow.