A High Integrity Protection System (HIPS) is a safety mechanismfor a process plant offering the same or better protection than a relief valve or rupture disc. Thecurrent standard for plant protection in the United Kingdom is EEMUA Publication 160', whichgives four basic categories for control and protection systems:
Category 0 System. A self acting mechanical device or system which is a protectionagainst dangers to personnel. Examples include relief valves, bursting discs or containment.
Category 1 System. A non self-acting system whichrequires an outside source of energy and which is a protection against the dangers to personnel.
Category 2 System. A system which protects against the damage to the environment, damage to the process plant, loss of product or production.
Category 3 System. A control system which ensuresreliable production and maintainsplant operation within the operational limits.