第一種：單作用常閉型

工作原理：

根據彈簧復位達到閥門關閉的作用，工作時只需安裝一根氣管，通氣閥門打開，失氣閥門自動關閉。在常壓常溫的情況下方便安裝使用。

FIRST: SINGLE-ACTING NORMALLY CLOSED TYPE

Working principle:

According to the spring retum to achieve the function of closing the valve, only one air pipe needs to be installed during work, the vent valve is opened, and the lost gas valve is automatically closed. It is easy to install and use under normal pressure and normal temperature.

第二種：單作用常開型

工作原理：

根據通氣關閉閥門，工作時只需安裝一根氣管，通氣閥門關閉，失氣閥門自動打開，在高溫高壓的情況，需要長期打開閥門的情況下可選用。

SECOND: SINGLE ACTING NORMALLY OPEN TYPE

Working principle:

According to the ventilation, the valve is closed. Only one air pipe is required to be installed during operation. The ventilation valve is closed and the lost gas valve is automatically opened. It can be used in the case of high temperature and high pressure and the need to open the valve for a long time.

第三種：雙作用帶彈簧關閉型（推薦）

工作原理：

根據通氣控制閥門開關，工作時需安裝兩根氣管，遇緊急情況（列停電）閥門可自動關閉，用戶還可與根據使用情況來自由安裝閥門方向，（在惡劣條件下介質高溫，高壓，氣缸壓力小，防水錘等安裝使用）控制更精確，更穩定。

THIRD: DOUBLE ACTING WITH SPRING CLOSING TYPE (RECOMMEND)

Working principle:

According to the spring retum to achieve the function of closing the valve, only one air pipe needs to be installed during work, the vent valve is opened, and the lost gas valve is automatically closed. It is easy to install and use under normal pressure and normal temperature.

第四種：雙作用（自由態）

工作原理：

根據通氣控制閥門開關，工作時需安裝兩根氣管，在控制執行器壓力較低的情況下使用，用戶可根據使用情況打開閥門后屬于常開狀態。在低壓低溫的情況下使用雙作用自由態可延長閥門壽命。

FOURTH: DOUBLE ACTING(FREE STATE)

Working principle:

According to the ventilation control valve switch, two air pipes need to be installed during operation, and it is used when the pressure of the control actuator is low. The user can open the valve according to the use situation and belong to the normally open state. The double-acting free state can prolong the life of the valve under the condition of low pressure and low temperature.