SIL Verification Study for HPCL Kozhikode | Ensuring Compliance & Safety
Ensuring Safety & Compliance with SIL Standards
Welcome to our comprehensive Safety Integrity Level (SIL) Verification Study for Hindustan Petroleum Corporation Limited (HPCL) Kozhikode IRD. Our expertise ensures that your Safety Instrumented Systems (SIS) comply with the required SIL levels, enhancing reliability, safety, and operational efficiency.
This report presents the Safety Integrity Level (SIL) Verification Study for Hindustan Petroleum Corporation Limited — Kozhikode IRD. The study’s purpose is to find the probability of failure on demand (PFD) of each SIF and assess the SIL achieved through the architectural constraints of the SIFs of HPCL tanks located at Elathur and check if they meet the target Safety Integrity Levels.
Reliability data of High-level switch, radar gauge, ESD push buttons, logic solver, actuators, and valves used in this study are taken from the SIL certificates provided by the manufacturers of sensors, Safety Relay, Logic Solvers, and Electro Hydraulic Actuated ROSOV.
Objectives of the SIL Verification Study
- Ensure that the Safety Instrumented System (SIS) meets the requirements of the identified SIL level.
- Recommend to improve proof test coverage and revise the proof test schedule for the safety systems under consideration to meet the safety requirements if found with any gap.
- Recommend improving diagnostic test coverage or revising the diagnostic schedule wherever required and possible.
- Recommend higher SIL-capable devices in the SIF loop if required.
Scope of Work
- The scope of work is to perform the SIL verification study for HPCL Elathur to verify if the classified SIFs in the present architecture of HPCL tanks meet the required SIL target level of 2.
- 2 types of SIF loops need to be verified, and the identical loops shall be referenced in the report.
- SIF Loop type 1 shall be studied for re-designing by removing the Level switch, and the sensor voting logic shall be changed from 1oo2 to 1oo1 without affecting the target SIL Level.
Methodology
The evaluation of SIL ratings has been conducted using reputed Software. The SIL achievement for a SIF is calculated via 2 methods:
⭐ SIL achievement via Probability of Failure on Demand (PFD)
The probability of failure on demand is calculated for the SIF items that have been chosen for SIL verification. The SIL level is then obtained using the table specified in the IEC 61511–1.
⭐SIL Achievement via Architectural Arrangement
Hardware Fault Tolerance
Hardware fault tolerance is the ability of a component or subsystem to continue to be able to undertake the required Safety Instrumented Function (SIF) in the presence of one or more dangerous faults in the hardware. A hardware tolerance of 1 means that there are two devices, and the architecture is such that the dangerous failure of one of the components or subsystems does not prevent the safety action from occurring.
IEC 61508 and IEC 61511 provide tables of minimum fault tolerance for each SIL level on a basis of the Safe Failure Fraction (SFF) of each component or subsystem. As part of SIL verification, GL has compared the SFF of the components in conjunction with the architecture to give a maximum SIL classification achievable by the function.
Architectural Constraints on Type A Safety-Related Sub-system (IEC 61508–2)
Architectural Constraints on Type B Safety-Related Sub-system (ref IEC 61508–2)
Conclusions and Recommendations
✅ The first loop was adjusted as per the client’s request and verified. After the changes, the required safety level was met.
✅ For the second loop, the desired safety level was not achieved with the current testing interval. It is recommended to modify the testing schedule to meet the target.
✅ For the third loop, the desired safety level was also not achieved with the current testing interval. Adjusting the testing schedule is recommended to meet the target.
Why Choose Us?
✅ Expertise in SIL Verification following IEC standards.
✅ Reliable safety assessments with advanced methodologies.
✅ Customized solutions to enhance proof test and diagnostic schedules.
✅ Recommendations for higher SIL-capable devices for improved safety.
Enhance your system’s reliability today! Contact us for expert SIL verification solutions.