GB/T 18691.4-2021Agricultural irrigation equipment - Irrigation valves - Part 4: Air valves (English PDF)

1 Scope

This document specifies the design requirements, performance requirements, conformity assessment, marking and packaging of intake and exhaust valves: This intake and exhaust valve is suitable for water temperature

Irrigation systems that do not exceed 60°C and whose water may contain certain types and concentrations of fertilizers or chemicals commonly used in agriculture:

This document applies to hydraulically driven irrigation intake and exhaust valves with a nominal size of not less than DN15:

The operation can be realized by applying force to the closing parts or by applying force to the opening and closing parts through a float through a mechanical lever: This type of valve is also available with an adjustable pilot valve

Apply force to operate:

2 Normative references

The contents of the following documents constitute essential provisions of this document through normative references in the text: Among them, dated citations documents, only the version corresponding to that date applies to this document; for undated references, the latest edition (including all amendments) applies to this document:

GB/T 18691:1-2021 Irrigation Valves for Agricultural Irrigation Equipment Part 1: General Requirements (ISO 9635-1:2014, IDT)

GB/T 18691:2-2021 Irrigation Valves for Agricultural Irrigation Equipment Part 2: Isolation Valves (ISO 9635-2:2014, IDT)

3 Terms and Definitions

The terms and definitions defined in GB/T 18691:1-2021 and the following terms and definitions apply to this document:

3:1

Intake and exhaust valve airvalve float-type purger

Automatic float valve for in-duct intake and exhaust control:

NOTE: These valves may be single float or double float with one or more of the following functions: exhaust, intake:

3:2 exhaust functionairreleasefunction

The function of removing air from water pipes or equipment:

3:3

Air intake function vacuum release function

A function that allows gas to enter water pipelines or equipment:

3:4 ventilation function

Continuous ventilation function continuousactingairventfunction

The function of discharging the trapped air in the pipeline under a certain pressure: […]