1. According to its overall structure, it can be divided into heavy hammer lever type, spring type and pulse type.

(1) 重錘杠桿閥

(1) Heavy hammer lever safety valve

? 重錘桿閥使用重錘和重錘桿來平衡作用在閥盤上的力。根據杠桿原理，它可以通過增加杠桿使用小砝碼來獲得大的力，并通過移動砝碼的位置(或改變砝碼的重量)來調節閥的開啟壓力。適用于高溫場合。

?  The heavy hammer rod safety valve uses a heavy hammer and a heavy hammer rod to balance the force acting on the valve disc. According to the lever principle, it can increase the lever and use a small weight to obtain a large force, and adjust the opening pressure of the safety valve by moving the position of the weight (or changing the weight of the weight). Suitable for high temperature applications.

(2) 彈簧微開閥

(2) Spring slightly open safety valve

彈簧微開閥利用壓縮彈簧的力平衡作用在閥盤上的力。可以通過轉動螺旋彈簧上的調整螺母來調整螺旋彈簧的壓縮。利用這種結構，可以根據需要校正閥的開啟(設定)壓力。它可用于移動式壓力容器。

The spring slightly open safety valve uses the force of the compression spring to balance the force acting on the valve disc. The compression of the coil spring can be adjusted by turning the adjusting nut on the coil spring. With this structure, the opening (set) pressure of the safety valve can be corrected as needed. It can be used for mobile pressure vessels.

(3) 脈沖閥

(3) Pulse safety valve

脈沖閥由主閥和輔助閥組成。輔助閥的脈沖動作驅動主閥的動作。其結構復雜。通常僅適用于排放量大的鍋爐和壓力容器。

Pulse safety valve consists of main valve and auxiliary valve. The pulse action of the auxiliary valve drives the action of the main valve. Its structure is complex. Generally, it is only applicable to boilers and pressure vessels with large safe discharge.

2.根據介質排放方式的不同，可分為全封閉式、半封閉式和開放式。

2. According to different medium discharge modes, it can be divided into fully closed, semi closed and open.

(1) 全閉式閥

(1) Fully closed safety valve

當全封閉閥排氣時，所有氣體通過排氣管排出，介質不能外泄。主要用于含有有毒、易燃氣體的容器。

When the fully closed safety valve exhausts, all gases are discharged through the exhaust pipe, and the medium cannot leak out. It is mainly used for containers containing toxic and flammable gases.

(2) 半閉式閥

(2) Semi closed safety valve

半閉式閥排出的部分氣體通過排氣管，部分氣體從閥蓋和閥桿之間的間隙泄漏。它主要用于介質為不會污染環境的氣體的容器中。

Part of the gas discharged from the semi closed safety valve passes through the exhaust pipe, and part of the gas leaks from the gap between the valve cover and the valve stem. It is mainly used in containers whose medium is gas that will not pollute the environment.

(3) 打開閥

(3) Open the safety valve

開啟式閥的閥蓋打開，將彈簧室與大氣連接，有利于降低彈簧溫度。主要適用于以蒸汽為介質、不污染大氣的高溫氣體的容器。

The valve cover of the open safety valve is opened to connect the spring chamber with the atmosphere, which is conducive to reducing the spring temperature. It is mainly applicable to the container of high-temperature gas with steam as the medium and does not pollute the atmosphere.

? 3.根據作用原理可分為直接作用型和間接作用型。

?  3. According to the action principle, it can be divided into direct action type and indirect action type.

(1) 直接作用閥

(1) Direct acting safety valve

直接作用閥是在工作介質的直接作用下開啟的，即依靠工作介質的壓力來開啟閥門，克服加載機構對閥盤施加的機械載荷。該閥結構簡單，動作迅速，可靠性好。但由于結構載荷的限制，其載荷有限，不能用于高壓和大直徑場合。

The direct acting safety valve is opened under the direct action of the working medium, that is, the valve is opened by relying on the pressure of the working medium to overcome the mechanical load imposed by the loading mechanism on the valve disc. The safety valve has the advantages of simple structure, rapid action and good reliability. However, due to the limitation of structural load, its load is limited and can not be used in high pressure and large diameter occasions.

(2) 非直接作用閥

(2) Non direct acting safety valve

? 這種閥可分為先導式閥和帶動力輔助裝置的閥。

?  This safety valve can be divided into pilot safety valve and safety valve with power auxiliary device.

?先導閥由先導閥排出的介質驅動或控制。適用于高壓、大直徑場合。這種閥的缺點是其可靠性與主閥和先導閥有關。其動作不如直動式閥快速可靠，結構復雜。

? The pilot relief valve is driven or controlled by the medium discharged from the pilot valve. Suitable for high pressure and large diameter occasions. The disadvantage of this safety valve is that its reliability is related to the main valve and pilot valve. Its action is not as fast and reliable as direct acting safety valve, and its structure is complex.

?帶動力輔助裝置的閥是在低于正常開啟壓力的情況下，借助動力輔助裝置迫使閥開啟。閥適用于開啟壓力非常接近工作壓力的場合，或需要定期開啟閥進行檢查或吹走粘合劑和凍結介質的場合。同時，它還提供了在緊急情況下強行打開閥的方法。

? The safety valve with power auxiliary device forces the safety valve to open with the help of power auxiliary device under the condition of lower than the normal opening pressure. The safety valve is suitable for occasions where the opening pressure is very close to the working pressure, or occasions where it is necessary to open the safety valve regularly for inspection or blow away the adhesive and frozen medium. At the same time, it also provides a method of forcibly opening the safety valve in an emergency.