scope:

This recommended practice is intended to apply to relieving devices and their discharge systems on pressure vessels designed for operating pressures of more than 15 psig. Other considerations, such as an estimation of the heat input from an exterior fire, are applicable to all vessels within refineries.

Pressure vessels used for transportation of petroleum products, in bulk or in shipping containers, are not within the scope of this recommended practice.

Inasmuch as pressure-relieving devices only protect a vessel against overpressure and not against a bursting failure when exposed to fire, means are suggested in this recommended practice both for reducing the pressure to near atmospheric and for restricting the heat input.