HIPPS Applications and Acceptance Criteria
Authors: Onshus T. , Aaro R. , Lund B.F. 
Published: October 2008

ABSTRACT
This paper gives a review of various applications of HIPPS and relevant acceptance criteria. The paper also discusses equipment available for HIPPS, safety requirements and conomic aspects, together with justification of the increased importance of maintenance and functional testing when HIPPS is introduced.
The application of HIPPS can in many applications reduce cost, and make marginal projects profitable. Realistic qualitative and quantitative evaluations against acceptance criteria are of crucial importance to avoid mistakes during design.
Before a HIPPS application can be utilized, acceptance criteria for the application has to be established, and the fulfillment of these has to be documented, concerning personnel safety, environmental pollution and economical feasibility on a life-cycle basis.

WHAT IS H.IPPS?
There are several different abbreviations that have been used for HIPPS functionality, such as:HIPPS - High Integrity Pressure Protection SystemHIPS - High Integrity Protection Shutdown systemOPPS - Over pressure Pipeline Protection System
Independent of naming, the objective usually is to replace a mechanical safety device with instruments, valves and logics. Several solutions for HIPPS are presently applied in gas distribution, hydrocarbon treatment plants, on off-shore plat- forms, and also evaluated for use in sub-sea production systems. Systems in operation or under design, known to the authors are:Gas distribution and storage, Germany (Ruhrgas, Thyssen, Statoil etc.)Frigg TP1/TCP2, North Sea (Elf)Karsto gas terminal, Norway (Statoil)St. Fergus gas terminal, Scotland (Total Oil Marine)Gullfaks A, North Sea (Statoil)Vandreil, Canada (Alcan)Karsto, Norway (Statoil)Sleipner Vest, North Sea (Statoil)Zeepipe, Belgium (Statoil)Etzel Gas-Lager, Germany (Statoil)
Pre-feasibility studies for sub-sea applications also exist: Hild (Total Norway), Visund (Norsk Hydro). See also Aar@ et.al, 95 and Lund et.al, 95.
Some of the German systems, mainly pneumatic, have been in operation since 1985, and experience is said to be very good but no details are available. Today 10-15 systems are in operation with an average of 4-5 years of operation.

WHY APPLY HIPPS?
The reason for applying these systems is usually to reduce cost (e.g. reduced design pressure and flaring), but also environmental issues like reduced C02 to the environment are considered.
The requirements for these systems may be given by recommendations and standards from CEN, 1S0, IEC, DIN, ISA, API etc. and regulations issued by governmental organizations like NPD and HSE. These regulations usually refer to the principles from e.g. API RP 14C, which for a pressure vessel requires for instance:Independence between control and safety functionsPrimary protection: PSH and isolationSecondary protection: PSV and flaring
The purpose of the HIPPS is to protect low-rated parts against overpressure, and it is important to bear in mind that HIPPS comes in addition to the PSD and ESD system, as it replaces a mechanical and independent safety device.
The requirements that have to be met by HIPPS installations are usually given by the conventional system it is replacing. The new design should be safer or equal to the design it is replacing.