The High-Integrity Pressure Protection System, or HIPPS, is an instrumented safety system designed to prevent plant over-pressurization (onshore-offshore platforms).
HIPPS interrupts the source of the high pressure before the limit is reached and exceeded, thus preventing the potential loss of containment through a line or tank rupture or explosion.
HIPPS provides a solution to protect equipment in cases where:
- High pressures and/or flow rates are processed
- The environment must be protected
- The economic viability of a development must be improved
- The risk profile of the facility must be reduced
HIPPS is an instrumented safety system designed and manufactured in accordance with the International Electrotechnical Commission’s IEC 61508 and IEC 61511 standards.
The basis for the design of the HIPPS Safety Instrumented System (SIS) is the required Safety Integrity Level (SIL).
SIL is obtained during the risk analysis of a plant or process and represents the required risk reduction. The SIS must meet the requirements of the applicable SIL, which ranges from 1 to 4.
IEC standards define the requirements of each SIL for the life cycle of the equipment, including design and maintenance. The SIL also defines the probability of failure on demand (PFD) for the entire loop and the architectural constraints for the loop and its different elements.
The PFD and RRF (risk reduction factor) of low demand operation for different SILs defined in IEC EN 61508 are as follows:
SIL |
PFD |
PFD (power) |
RRF |
1 |
0.1-0.01 |
10 -1 – 10 -2 |
10-100 |
2 |
0.01-0.001 |
10 -2 – 10 -3 |
100-1000 |
3 |
0.001-0.0001 |
10 -3 – 10 -4 |
1000-10,000 |
4 |
0.0001-0.00001 |
10 -4 – 10 -5 |
10,000-100,000 |
HIPPS is a complete functional circuit consisting of:
- Sensors (or initiators) that detect high pressure
- A logic solver, which processes the input from the sensors to obtain an output to the final element
- Final elements that perform the corrective action in the field by bringing the process to a safe state by interrupting the source of overpressure
- The final element consists of a valve, actuator and solenoids.