OISD 118 Valve Requirements for Indian Oil & Gas Installations

The Oil Industry Safety Directorate (OISD), under India's Ministry of Petroleum and Natural Gas, publishes mandatory safety standards for the Indian upstream and downstream oil & gas sector. OISD Standard 118 — 'Layout Requirements for Oil and Gas Installations' — is one of the core documents governing how processing plants are designed and what equipment must be installed. For valve procurement engineers at ONGC, IOCL, BPCL, HPCL, GAIL, and EPC contractors serving these PSUs, OISD 118 compliance is not optional.

What is OISD and Why Does it Matter?

The Oil Industry Safety Directorate (OISD) was established in 1986 following major accidents in the Indian petroleum sector. It is a technical directorate under the Ministry of Petroleum and Natural Gas and serves as the statutory authority for safety in India's oil and gas industry. OISD standards are mandatory for all Public Sector Undertakings (PSUs) in the sector and are adopted as conditions of license for private operators. Non-compliance can result in refusal of statutory approvals, insurance issues, and personal liability for plant managers.

Key Valve Requirements Under OISD 118

Fire-Safe Valve Specification

OISD 118 requires fire-safe valves at critical isolation points in hydrocarbon service. Fire-safe certification means the valve has been tested per API 607 (fire testing of quarter-turn valves) or API 6FA (fire testing of gate, globe, and check valves). A fire-safe valve must demonstrate acceptable leakage through the body and seat after 30 minutes of exposure to a controlled fire test at 871°C ± 55°C, followed by a hydrostatic test. All ball and butterfly valves specified for hydrocarbon service at any PSU must carry API 607 / ISO 10497 fire-safe certification.

Material Groups for Valve Bodies

OISD 118 references the ASME B31.3 fluid category system for material selection. For hydrocarbon services classified as 'Category D' (non-flammable, non-toxic, design temperature −29°C to 186°C, design gauge pressure ≤1,035 kPa), carbon steel A216 WCB is the standard body material. For 'Category M' (highly toxic fluids) and ASME B31.3 'Normal Fluid Service' hydrocarbons, alloy steels and stainless are required based on fluid properties. Flanged end connections per ASME B16.5 are required for sizes 2" NPS and above in hydrocarbon duty.

Emergency Shutdown Valves (ESDVs)

A critical valve requirement under OISD 118 is the provision of Emergency Shutdown Valves (ESDVs) at the battery limit of each processing unit, at storage tank inlets/outlets, and at pipeline feed/offtake points. ESDVs must be fail-safe (spring-return actuator, spring-to-close on loss of signal), SIL-rated to the appropriate Safety Integrity Level per the process hazard analysis (PHA), and capable of closing in ≤10 seconds (fast-acting) for flammable gas service. All ESDVs must have position feedback (open/close limit switches) to the control room.

Isolation and Blinding Philosophy

OISD 118 specifies that positive isolation (blind flanging, spectacle blinds, or spades) must be provided for maintenance isolation on all process equipment in hydrocarbon service. Valves alone are not considered positive isolation for hot work or confined space entry — a physical spectacle blind must be installed and confirmed. This drives the piping layout requirement for blindable spool pieces adjacent to critical isolation valves. Procurement teams must account for DNV spacing requirements when specifying gate or ball valves near vessels.

Valve Documentation Required for OISD Compliance

• Material Test Certificates (MTCs) per EN 10204 Type 3.2 (third-party witnessed) for all pressure-containing parts
• Hydrostatic test certificates per API 598 or BS 6755 at 1.5× design pressure
• Fire-safe test certificate per API 607 / ISO 10497 (for quarter-turn valves in hydrocarbon service)
• NABL-accredited laboratory reports for chemical and mechanical property tests
• Dimensional inspection report per relevant API/ASME standard
• Valve tag data sheet (P&ID tag number, service, design conditions, material, end connection)
• Third-party inspection (TPI) release note from an approved agency (Bureau Veritas, SGS, Lloyd's, DNV, RINA, Intertek)

OISD-Approved Valve Manufacturers and Vendors

Major Indian PSUs maintain their own Approved Vendor Lists (AVLs) that reference OISD requirements. For valves to be procured for IOCL, BPCL, HPCL, or ONGC projects, the valve manufacturer must typically be on the project owner's AVL or the EPC contractor's approved vendor list. Vajra Industrial Solutions supplies from manufacturers with API monogram licensing, IBR registration (for steam service), and fire-safe certifications, covering all documentation requirements for OISD-governed projects.

Valve Classes Commonly Used in OISD 118 Compliance