ISO 4126-9:2008 過度の圧力から保護するための安全装置—パート9：スタンドアロンの破裂ディスク安全装置を除く安全装置の適用と設置 | ページ 6

3.1

safety device

device that serves as the ultimate protection to ensure that the maximum allowable accumulated pressure is not exceeded

3.2

safety system

system including the safety devices and the interconnections between the equipment to be protected and any discharge connection to the nearest location of a safe disposal place

Note 1 to entry: This location can either be an atmospheric outlet or the connection into a safe collecting system or flare.

3.3

fail-safe

status such that the pressure equipment remains in a safe condition in case of failure of any safety system component or energy source

3.4

self-diagnosis

regular and automatic determination that all chosen components of a safety system are capable of functioning as required

3.5

redundancy

provision of more than one device or system such that the necessary function will still be provided in case of failure of one or more of these devices

3.6

independence

ability to function as required without interference from other equipment

3.7

hazard

potential source of harm

Note 1 to entry: The term “hazard” can be qualified in order to define its origin or the nature of the expected harm (see ISO/IEC Guide 51).

Note 2 to entry: Harm is the physical injury or damage to the health of people, or damage to property or to the environment.

3.8

risk

combination of the probability of occurrence of harm and the severity of that harm

Note 1 to entry: See ISO/IEC Guide 51.

3.9

risk analysis

use of available information to identify hazards and to estimate the risk

Note 1 to entry: See ISO/IEC Guide 51.

3.10

risk evaluation

judgement on the basis of risk analysis as to whether a tolerable risk has been achieved

Note 1 to entry: See ISO/IEC Guide 51.

3.11

risk assessment

overall process of risk analysis and risk evaluation

Note 1 to entry: See ISO/IEC Guide 51.

3.12

reliability

ability to perform a required function under specified conditions and for a given period of time without failing

3.13

pressure limiter

device which ensures that the permitted maximum allowable pressure is not exceeded during continuous operation

Note 1 to entry: It activates the means for correction, or provides for shutdown or shutdown and lockout.

3.14

safety

freedom from unacceptable risk

Note 1 to entry: See ISO/IEC Guide 51.

3.15

maximum allowable pressure

P _S

maximum pressure for which the equipment is designed, as specified by the manufacturer

3.16

maximum/minimum allowable temperature

T _S

maximum/minimum temperatures for which the equipment is designed, as specified by the manufacturer

3.17

accumulated pressure

pressure in the equipment to be protected which can exceed maximum allowable pressure for a short duration during the operation of safety devices

3.18

maximum allowable accumulated pressure

P _S,accum

maximum allowable value of the accumulated pressure in the equipment being protected which is fixed by national codes, regulations or directives