ISO 5115:2023 工業用バルブ | ページ 6

3.1

actuator

device designed for attachment to a general-purpose industrial valve in order to provide for the operation of the valve

Note 1 to entry: The device is designed to operate using motive energy which may be electrical, pneumatic, hydraulic, etc., or any combination of these. Movement is limited by travel or torque.

[SOURCE:ISO 5211:2017, 3.1]

3.2

breakaway angle

amount of valve stem (3.22) rotation before the obturator (3.9) breaks sealing contact with the seat

Note 1 to entry: The breakaway angle can be significant to actuator (3.1) sizing when more than 5° of rotation.

3.3

breakaway torque

maximum torque required to operate a valve at maximum pressure differential

Note 1 to entry: Breakaway torque is a general term that applies to the valve break to open torque and the valve break to close torque.

3.4

MAST

maximum allowable stem torque

maximum torque that can be applied to the valve stem (3.22) or coupling, as defined by the manufacturer, without causing permanent deformation or mechanical damage that prevents sealing or operation

3.5

cycle

movement of the valve obturator (3.9) from the fully closed position to the fully open position and back to the fully closed position, or vice versa

[SOURCE:ISO 12490:2011, 4.8, modified — The word “continuous” at the beginning of the definition has been removed.]

3.6

DN

NPS

nominal size

alphanumeric designation of size that is common for components used in a piping system, used for reference purposes, comprising the letters DN or NPS followed by a dimensionless number indirectly related to the physical size of the bore or outside diameter of the end connections

Note 1 to entry: The number following DN or NPS does not represent a measurable value and is not used for calculation purposes except where specified in a product standard.

[SOURCE:ISO 5208:2015, 2.7]

3.7

intermediate support

mechanical component (e.g., bracket, spool, adapter flange) being part of a mounting kit (3.8) that allows the attachment between a valve and actuator (3.1)

3.8

mounting kit

components that can include combinations of the following: intermediate support, coupling, drive key(s), dowel pin(s) and fasteners

3.9

obturator

part of a valve, such as a ball, clapper, disc, gate or plug that is positioned in the flow stream to permit or prevent flow

[SOURCE:ISO 14313:2007, 4.19, modified — The term “closure member” has been removed.]

3.10

differential pressure

Δp

pressure difference across the upstream and downstream sides of the obturator (3.9) seals when it is in the fully closed, partially open, or fully open position

3.11

maximum rated pressure

maximum pressure that can safely be applied in the pressure-containing parts of a pneumatic or hydraulic actuator (3.1) as defined by the actuator manufacturer

3.12

maximum supply pressure

maximum available pressure to supply at a pneumatic or hydraulic actuator (3.1) pressure inlet port as defined by the purchaser

3.13

minimum operating pressure

minimum required pressure to supply at a pneumatic or hydraulic actuator pressure inlet port to operate the actuator (3.1) as defined by the actuator manufacturer

3.14

minimum supply pressure

minimum available pressure to supply at a pneumatic or hydraulic actuator (3.1) pressure inlet port as defined by the purchaser

3.15

sizing safety factor

SSF

numerical value that is multiplied to the valve operating torque that is used when selecting an actuator (3.1)

3.16

stroke

travel of the valve obturator (3.9) from the fully closed to the fully open position, or vice versa

Note 1 to entry: End of stroke is predefined as the fully closed or fully open position.

[SOURCE:ISO 12490:2011, 4.25, modified — The Note 1 to entry has been added and the word “movement” has been substituted by “travel”.]

3.17

travel

movement of the actuator (3.1) in driving a valve obturator (3.9) , defined in terms of output turns, angular or linear distance, a percentage thereof or undefined when relating to general movements(s)

[SOURCE:ISO 22153:2020, 3.13]

3.18

valve dynamic torque

T_d

torque generated by flow of media through valve and around the obturator (3.9)

[SOURCE:Reference [14]]

3.19

C_t

valve dynamic torque coefficient

dimensionless coefficient used to determine the flow induced torque on the obturator (3.9) as a function of valve geometry, flow rate, and valve position

[SOURCE:Reference [14]]

3.20

valve operation time

period between when the signal is given for the valve to operate, starting from the fully open position and ending at the fully closed position or vice versa

3.21

valve response time

period between when the signal is given for the valve to operate until the obturator (3.9) starts to move

Note 1 to entry: With electric actuators (3.1) , a valve response time is not relevant.

3.22

valve stem

part of the valve transmitting the driving torque to the obturator (3.9)

Note 1 to entry: This concept also referred to as valve shaft or valve spindle in product standards, is collectively identified herein as valve stem.

3.23

valve travel time

period between when obturator (3.9) starts to move starting from the fully open position and ending to the fully closed position or vice versa

3.24

valve torque

required input torque at the valve stem at the moment there is relative movement between the obturator (3.9) and seat(s)

Note 1 to entry: This torque can vary depending on the valve starting position and internal pressure.