ISO 11738:2021 農業灌漑設備—コントロールヘッド | ページ 5

3.1

activating valve

type of valve which is used to initiate and shut off the flow of water through an irrigation control head (3.8)

3.2

automatic self-cleaning strainer-type filter

filter with a flushing capability automatically activated by pressure differential, by duration of infiltration, by volume of water filtered, by some other physical quantity or by any combination of these

3.3

air release valve

valve which opens automatically to allow air from the atmosphere to enter the water pipeline during drainage of the line and/or venting of air from the water pipeline to the atmosphere during filling or during normal operation of the pipeline under pressure

3.4

backflow preventer

mechanical assembly to prevent flow of water backwards into the distributing pipes of a water supply system to protect against entry of substances which can constitute a health hazard

3.5

check valve

valve which permits flow of water in one direction only

3.6

fertilizer injector tank

pressure vessel connected to an irrigation system (3.9) in an in-line or on-line configuration, together with the pipes and fittings connecting it to the irrigation system, for the purpose of injecting chemicals into the irrigation system

3.7

water-driven chemical injector pump

hydraulic pump intended to inject chemicals into an irrigation system (3.9) , powered by a single source energy supplied by irrigation water (3.10) through a hydraulic motor, such as a piston or turbine

3.8

irrigation control head

assembly of components and pipes installed at the head of an irrigated plot which serves to control the functioning of an irrigation system (3.9) , that is, initiation and shutting off of the flow of water, pressure regulation, water metering, filtration (3.19) and injection of chemicals

3.9

irrigation system

assembly of pipes, components, and devices installed in the field for the purpose of irrigating a specific area

3.10

irrigation water

water of potable quality, which may contain chemicals of a type and concentration generally used in agricultural irrigation or which is of a quality approved for use in irrigation

3.11

nominal size of an irrigation control head

numerical designation used to refer to the size of the pipe at the inlet or the outlet, whichever is smaller, of an irrigation control head (3.8)

3.12

nominal size of a component

numerical designation used to refer to the size of an irrigation control head (3.8) which is identical to the nominal diameter of the pipe or pipes to which the irrigation control head is intended to be connected directly without an intermediate fitting

Note 1 to entry: A single number designation is adequate if the inlet and outlet ports are of the same size.

3.13

pressure regulator

valve in which the water passage widens or narrows automatically without an external device to maintain the pressure at the outlet of the valve close to a pre-set value under varying pressures or flow rates at the inlet of the valve

3.14

union

threaded coupling which is used to connect two pipes and which does not require rotation of the pipes during assembly and disassembly

3.15

media filter

filter in which clogging material is trapped within the interior of a three-dimensional filter medium, such as sand, gravel, textile, fibres or a porous mass of bonded particles

3.16

strainer-type filter

strainer

device containing one or more filter elements, such as a screen or a mesh, used for separating clogging material from water flowing through the device by collecting it on the surface of the filter element or elements

[SOURCE:ISO 9912‑1:2004, 2.8]

3.17

volumetric valve

valve capable of automatically delivering pre-set volumes of water within the range of flow rates, as a result of measuring the volume of water flowing through the valve

[SOURCE:ISO 7714:2018, 3.1]

3.18

pressure regulation

reduction of pressure prevailing in a supply line to maintain it at a relatively constant pre-set value in an irrigation system (3.9)

3.19

filtration

process which employs a permeable medium and/or a spinning component to separate, from water, any materials that would clog an irrigation system (3.9) and which also employs a means for removing these materials from the permeable medium or the spinning component in order to renew the capacity of the permeable medium or the spinning component to separate these materials from the water

3.20

chemigation

injection of chemicals, including fertilizers, into irrigation water (3.10) and conveyance of these chemicals to plants

3.21

automation

methods and means of activating or terminating operation of an irrigation system (3.9) or of changing its operating conditions according to a preconceived plan and without manual intervention

3.22

flow regulation

function intended to control the flow rate of water to reduce it to that required in an irrigation system (3.9) and maintain it at a relatively constant value