OISD 150
Fired Heater Safety Standard
OISD 150 is the Oil Industry Safety Directorate standard governing fired heater design, operation, and safety provisions at Indian refineries and petrochemical plants. The standard codifies burner management system (BMS) requirements, fired heater layout, emergency shutdown logic, and inspection cycles. Every fired heater in an Indian hydrocarbon plant operates under OISD 150 compliance.
OISD 150 (Oil Industry Safety Directorate Standard 150, 'Design and Operation of Fired Heaters') is the mandatory safety standard for fired heaters at Indian petroleum and petrochemical installations. Maintained by OISD under the Ministry of Petroleum and Natural Gas (MoPNG), the standard codifies fired heater layout, burner management system (BMS) requirements per IEC 61511 SIL classification, emergency shutdown valve provisions, flame failure detection, fuel gas knockout drum sizing, and periodic inspection cycles. Compliance is verified during MoPNG and OISD audits. See the OISD 118 standard for the broader layout framework that includes fired heaters.
Fired heater scope
Fired heaters covered by OISD 150 include crude heaters, vacuum heaters, reformer heaters, hydrocracker heaters, hydrotreater heaters, coker heaters, ethylene cracker furnaces, and direct-fired reboilers. Each fired heater type has specific BMS, layout, and inspection requirements driven by the heat duty, fuel type (fuel gas, fuel oil, dual fuel), and process service criticality.
Burner Management System (BMS)
OISD 150 mandates SIL 2 or SIL 3 Burner Management System on every fired heater per IEC 61511 functional safety methodology. The BMS handles burner start-up sequence, flame failure detection, low fuel pressure shutdown, high fuel pressure shutdown, low combustion air shutdown, and emergency shutdown valve actuation. BMS architecture must be independent of the process control system (PCS) for fail-safe operation.
Layout and emergency response
Fired heater layout requirements include minimum separation from process equipment, dedicated emergency response access, fire-water capacity computed per fired heater duty, and emergency shutdown station location. Layout drawings must be archived as part of the fired heater compliance package and revalidated at major modifications.
Inspection and audit
OISD 150 prescribes periodic inspection cycles for fired heaters: BMS validation testing (annual), burner inspection (per maintenance cycle), structural inspection (per refractory maintenance), and full audit during 2-3 year OISD audit cycles. Non-conformities flagged during audits typically include BMS deviation logs, missing flame detector calibration, or expired safety device certification.
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Indian PSU refineries operate 10-50 fired heaters per complex covering crude distillation, vacuum distillation, reforming, cracking, coking, and hydrotreating units.
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Greenfield refinery and petrochemical EPC projects must demonstrate OISD 150 compliance at fired heater mechanical completion. The compliance package includes BMS architecture, fired heater layout, emergency response provisions, and inspection cycle.
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Petrochemical plants with ethylene cracker furnaces (Reliance, GAIL, IOCL Panipat petrochemical) operate cracker furnaces under OISD 150 with specialised BMS and SIL classification requirements.
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Brownfield revamp projects modifying existing fired heaters (efficiency improvement, capacity expansion, fuel switch from oil to gas) require OISD 150 delta compliance verification.
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EPC contractors (L&T, Tata Projects, Engineers India Limited, Toyo) delivering fired heater scope to Indian PSU clients produce OISD 150-compatible deliverables alongside engineering deliverables.
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Inspection day preparation for OISD audit on a major refinery typically requires consolidated fired heater compliance documentation across all units. Pathnovo's HAZOP and compliance automation accelerates audit preparation.
Pathnovo's HAZOP Safety Intelligence pillar extracts HAZOP studies covering fired heater nodes from study PDFs and maps every recommendation to current P&ID revisions and BMS architecture. For OISD 150 audit-readiness, the structured HAZOP register surfaces fired heater nodes specifically, with safeguard, recommendation, and closure status queryable across the plant. Combined with the Indian EPC compliance bundle, Pathnovo produces inspector-ready OISD 150 compliance documentation packs for MoPNG and PNGRB review.
What is OISD 150?
OISD 150 is the Oil Industry Safety Directorate standard governing fired heater design and operation at Indian petroleum and petrochemical installations. The standard codifies burner management system (BMS) requirements, fired heater layout, emergency shutdown provisions, and periodic inspection cycles.
Which fired heaters does OISD 150 cover?
OISD 150 covers all fired heaters at Indian hydrocarbon installations: crude heaters, vacuum heaters, reformer heaters, hydrocracker heaters, hydrotreater heaters, coker heaters, ethylene cracker furnaces, and direct-fired reboilers across refineries, petrochemical plants, and gas processing facilities.
What SIL classification does OISD 150 require for BMS?
OISD 150 mandates SIL 2 or SIL 3 Burner Management System per IEC 61511 functional safety methodology depending on fired heater criticality. The BMS handles burner start-up, flame failure detection, fuel pressure shutdowns, combustion air monitoring, and emergency shutdown valve actuation independently of the process control system.
How does OISD 150 relate to OISD 118?
OISD 118 is the broader layout and safety standard for Indian petroleum installations. OISD 150 is the fired heater-specific standard within the same framework. Fired heaters must comply with OISD 118 inter-distance and layout requirements plus OISD 150 BMS and operation requirements.
How often does OISD 150 inspection occur?
BMS validation testing annually. Burner inspection per maintenance cycle (typically 2-3 years). Structural inspection during refractory maintenance. Full audit during 2-3 year OISD audit cycles. Non-conformities flagged during audits typically include BMS deviation logs, expired flame detector calibration, and safety device certification gaps.
Can Pathnovo automate OISD 150 audit preparation?
Yes. Pathnovo's HAZOP Safety Intelligence pillar extracts HAZOP studies covering fired heater nodes and surfaces safeguards and recommendations for audit-readiness. Combined with the Indian EPC compliance bundle, the structured output supports MoPNG and PNGRB audit review.
HAZOP Safety Intelligence
Fired heater HAZOP node extraction and audit-readiness.
OISD 118 Standard
Broader layout standard within which OISD 150 sits.
Indian EPC Compliance Bundle
IBR + OISD 118 + PESO + CCOE unified compliance.
SIL Standard
Safety Integrity Level classification for BMS.
Indian EPC AI for Hydrocarbons
Indian PSU refinery and petrochemical engineering AI.
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