HIPPS – High Integrity Pressure Protection System

As oil and gas resources become harder to find, producers are forced to operate in
environments of ever increasing severity and risk. Often operating in High Temperature
High Pressure (HTHP) applications, the consequences of a catastrophic failure to
personnel, the environment and infrastructure are immense.
To help manage the increasing and unprecedented risk, the concepts of Safety
Instrumented Systems (SIS) and Safety Integrity Levels (SIL) were created and applied.
One such SIS type, is the High Integrity Pressure Protection System (HIPPS). A HIPPS is
an independently instrumented protective device, and acts as the last line of defence for
protecting downstream operations from over pressurization.
Typically certified to SIL3, a HIPPS gives operators the most dependable pressure
protection device available in the market today

PROTECTING YOUR ASSETS

Traditionally, the risk of over-pressure events has been managed through the use of
mechanical relief systems which open to relieve excess fluid to disposal systems such as
flare or holding tanks. Although simple, relatively low cost and widely available, mechanical
relief systems often require a large installation footprint, and are far from ideal when the
process fluid is flammable or toxic.
Typically operators select a HIPPS when:

• High pressures or flow rates are required
• The environment needs to be protected from process fluid contamination
• The economic viability of an installation needs improvement
• The risk level of an installation needs to be reduced
  
  In addition to optimum pressure protection, HIPPS offer operators significant CAPEX and
  OPEX savings.

New Installations

• Avoids the requirement for expensive flare systems and pressure relief valve manifolds
• Offer significant weight savings for offshore installations
• For wellhead installations, allows pressure ratings for downstream piping and instrumentation to be reduced

Existing Installations

• Avoids the requirement to upgrade flare systems and pressure relief valve manifolds

HIPPS PRINCIPLE

Definition & Philosophy  

HIPPS is the acronym for High Integrity Pressure Protection System. Main function of HIPPS is an independently instrum whose function is to protect an installation from the overpressure produced in the high pressure part of the same, isol pressure part from it.
Idea of HIPPS is to be used instead of traditional safety systems such as relief devices with four main advantages:

Environment protection: relief systems release the service fluid to the atmosphere which while HIPPS avoid flui released out of the system keeping the environment free of emissions.

HIPPS have to be a safety level equal or higher than the traditional relief methods; calculated safety levels show to be ten times more reliable than traditional methods.

Creating a frontier between two parts of the installation allows the downstream part of the valves of the HIPP lower pressure and therefore, to reduce the cost of pipes and related pressure equipments installed on that part.

Hipps Scheme 

The exact configuration of a HIPPS System will be dependent on the specific application;
however, as a minimum all HIPPS Systems include the following components:
One defining characteristic of all HIPPS is the duplication of system components to provide
failure redundancy; ultimately resulting in higher system integrity. Below is a common HIPPS
architecture showing redundant pressure transmitters, valve actuators, solenoid valves and
block valves.

• Mainline valve
• Valve actuator
• Valve actuator control system
• Logic solver

APPLICABLE STANDARDS AND SAFETY INTEGRITY LEVEL 

HIPPS are designed according to following standards:

• IEC 61508: “Functional Safety of Electrical/Electronic/Programmable Electronic Safety Related System”.
• IEC 61511: “Functional Safety: safety instrumented systems for the process industry sector”.
• ANSI/ISA S84.01: “Application of Safety Instrumented Systems of the Processed Industries”.

Standards mentioned above are performance based so design of HIPPS is also based on the required Safety Integrit SIL has four categories, from 1 to 4, and it is defined by plant end user by means of making a risk analysis of the p related to the fulfillment of the tolerance risk: this means that SIL level results of the combination of two factors:

• Frequency of fail occurrence.
• Consideration of the consequences of fail (dangerous failure or safe failure)

Safety Instrumented Function (SIF) defines the level of protection against failure and it is defined by the Probability o Demand (PFD). PFDavg is defined as the average probability of failure the safety function between 0 to 1. Standard defines the maximum allowable PFDavg value depending how often the demand of SIF is:

• High demand: safety demand interval shorter than one year
• Low demand: safety demand interval longer than a year.

SIL Level is related to a this PFDavg value and must be considered for the complete functional loop, all its elements an between them

Maverick Valves – HIPPS IS PROVIDED

KEY FEATURES & BENEFITS

Maverick HIPPS Systems provides fully certified HIPPS with the following key features and benefits:

• Full engineering design support for any HIPPS application
• Full compliance with IEC 61508 Edition 2 up to SIL3; including system and sub-system calculations and documentation set:
• ► SIL calculations ► Safe failure fractions ► HFT requirements ► Partial Stroke Testing (PST) frequency determination ► 3 rd party certification
• Fast closure times down to 2 seconds
• API and ASME valves up to 60”
• Skid design and fabrication
• Installation, commissioning and servicing support to maintain SIL certification levels
• Valve actuator designs and manufacturing based on over 30 years’ experience in the Oil & Gas industry
  • Spring-return scotch-yoke or linear piston designs reflecting over thirty years experience with providing valve automationsolutions for the most demanding applications in the Oil & Gas industry

• World class and proven logic solver

Working with our Sira/CASS certified technology partner, we provide TUV/AK6 certified logic solvers. Our logic solvers use standard, proven and function block software which allows for numerous options such as partial stroke testing, and valve function logging to support preventative maintenance programs. Communications to all major DCS systems and customized third party communications interfaces are also available. The SIS controller can be provided up to a range of IEC 61508 SIL3 platforms to include scalable 2oo3 pressure transmitters and 1oo2 solenoid valve packages. The final SIS choice is dictated by functionality and availability requirements, system costs and client preferences. All systems are independently third party certified to ensure compliance with all current legislation and industry standards.

• Full diagnostics capability
• Compact manifold design control systems

Bespoke systems available for any HIPPS applications. Manifold designs to maximize robustness and reliability

• Hydraulic power units

• All instrumentation

Ball Valves
Typically will be trunnion mounted, double block bleed ball type due to proven tight shutoff, high reliability and low operating torque requirements. Ultimately the final valve
selection will be based on application specifications and end user preference.

Standard features

• Bidirectional flow.
• Trunnion Design for Low Torque Operation.
• Soft seated or Metal Seated construction.
• Automatic Cavity Pressure Relief.
• Anti Blow-Out Stem.
• Grease Fittings.
• Drain and vent.
• Antistatic Device.
• Fire Safe Design & Certified API 6FA, API607 and BS6755.

Optional features

• Double piston effect.
• Double Block-Bleed.
• Locking Device.
• Flanged grease fittings, vents and drains.
• Stem extension.
• Low emission packing.
• Live loaded packing.
• Lip Seals.

Axial Valves

Design:
A stream lined body with constant sectional area, offers a very reduced coefficient resistance and gives larger Cv values for the same sizes.

Fluid is channeled into an annular path between the inner and outer bodies until it reaches the characterized cage. Smooth changes in flow direction and no turbulences contribute to lower noise levels. The high capacity, combined with the large range ability, make our axial valve to be acknowledged as the ideal design to control over the full range of process conditions with a single valve.

As an option extended body neck is offered for cryogenic operations, with a variety of sealing wafer. Zero emission is guaranteed by the O-ring seals combined with back- up packing. Distance between flanges is in accordance with ISA 75.03 when data are available or API 6D for larger sizes. All types of quarter turn actuator are easily mounted.

Advantages :

• Larger Cv value, combined with high rangeability.
• Standard at 90° reduced torque actuator.
• No backlash, low friction drive mechanism, with reduced torque requirements.
• Zero stem leakage.
• Cage guided balanced plug for smooth operation.
• Linear, equal percent or other characteristics.
• Effective noise reduction and cavitation.
• Soft seated, bubble tight shut-off.
• Variety of cage designs to handle gas and liquid critical applications.

Actuators

Actuators assembled with MVM valves for the HIPPS systems can be pneumatic or hydraulic and they are supply in full compliance with customer specifications. Actuators include the control panel as specified, with solenoid valves.

Partial Stroke Test is available depend on SIL classification requirements.

FACTORY ACCEPTANCE TEST / SIL CERTIFICATION OF THE COMPLETE HIPPS

Maverick has state of the art facilities for the assembly and testing of the final elements and integration of the HIPPS system.
MVM together with our partners offers full integration of the HIPPS elements in the factory: initiators, logic solver and final elements (valves + actuators + control panel):

Performance of Factory Acceptance Test of the completely integrated HIPPS. Test can be witnessed by customer or by his nominated Third Party Inspection agency.