ISO 21843:2018 圧力容器用の防火材料およびシステムの炭化水素プール火災に対する耐性の決定 | ページ 6

3.1

blowdown valve

BDV

blowdown device

valve or device that opens to depressurize a pressure vessel

3.2

burner arrangement

configuration of the equipment designed to engulf the test specimen in fire, with specific reference to the size, orientation, frequency and spacing of burner heads, and the design of fuel supply piping

3.3

burst pressure

calculated burst pressure

<vessel> pressure that gives a hoop stress equal to the ultimate strength of the vessel material at the specific wall temperature of interest

Note 1 to entry: For long duration tests, stress rupture analysis is also considered a realistic failure mode.

3.4

calibration test

test performed by the laboratory prior and separate to customer tests, to confirm that the chosen burner arrangement in combination with the desired test specimen conforms with the required conditions of this document

3.5

critical pressure

pressure calculated for a given critical wall temperature as the burst pressure divided by a factor of safety (FOS)

3.6

critical temperature

design limiting temperature, or a specified limiting wall temperature, that the vessel wall temperature shall not exceed during fire exposure

Note 1 to entry: This temperature is related to a factor of safety (FOS) for the vessel when exposed to fire.

3.7

directional flame thermometers

DFTs

passive thermocouple based sensors that can be used for the measurement of both temperature and heat flux

Note 1 to entry: Various designs are available. A simple design is described in this document.

3.8

factor of safety

FOS

ratio of the calculated ultimate strength of the vessel steel at the temperature of interest (e.g. critical temperature) divided by the actual hoop stress in the vessel

Note 1 to entry: A typical FOS is in the range 2 to 3.

3.9

fire protection system

thermal protection system

protection afforded to the vessel to reduce the rate of heat transfer from the fire to the vessel, throughout the period of exposure to fire, including any protection materials together with any encasement (such as a jacket), and supporting system (such as mesh reinforcement or framing system) and any specified primer and top coat if applicable

Note 1 to entry: Often referred to as a thermal protection system in North America.

3.10

pool fire

hydrocarbon diffusion fire that occurs over a static or flowing release of flammable liquids

Note 1 to entry: It simulates large turbulent diffusion flames that are strongly radiating.

3.11

pressure relief valve

pressure safety valve

PRV

pressure-activated valve intended to limit pressure rise to a specified value

Note 1 to entry: These valves have set opening and reclosing pressures.

3.12

pressure vessel

vessel capable of containing pressures significantly above ambient, even if normal operational procedure does not involve pressure rise above ambient

Note 1 to entry: Pressure vessels are often referred to as vessels or tanks.

3.13

radiation-convection balance

fraction or percentage of total heat transfer to a cool surface that is due to radiation

Note 1 to entry: The cool surface may be a water-cooled calorimeter at a temperature of up to 100 °C.

3.14

test related tube and pipe

additional tube or pipe added to the vessel for the purposes of performing tests

Note 1 to entry: They may not be present on the real application tank.

3.15

total containment pressure vessel

pressure vessel that has no automatic means of pressure relief or depressurization

3.16

ullage space

vapour-filled space at the top of the vessel ここで, there is no liquid contact with the wall

3.17

vessel shell

primary wall of the vessel