1. The structure can be divided according to the safety valve:

① Hammer (lever) safety valve: with lever and weight to the pressure balance valve flap. Hammer safety valve by moving or changing the position of the hammer hammer weight adjustment pressures. It has the advantage of simple structure; drawback is relatively bulky back seat power is low. The valve structure for fixing the device only.Shown in Figure"

② Spring safety valve: the use of force to compress the spring pressure balance valve flap and make it sealed. Spring safety valve by adjusting the amount of compression of the spring to adjust the pressure. It has an advantage over hammer safety valve, small size, lightweight, high sensitivity, the installation location is not strictly limited; drawback is that the force acting on the valve stem with spring deformation and change.

Must also pay attention to the spring of insulation and heat. Spring-loaded safety valve spring force generally not more than 2000Kg. Because excessive excellent spring unfit precise work.

③ Pulse valve: pulse valve from the main valve and auxiliary valve. Main valve and auxiliary valve connected together through auxiliary valve pulses drive the main valve action.

Pulse valve is usually used for large diameter pipeline. Because large diameter valves, such as when using the hammer or spring not to adapt. Pulse valve from the main valve and auxiliary valve two parts. When the pipeline medium exceeds the rated value, the auxiliary valve first action driven main valve action, emit excess media.

2. According to the safety valve valve maximum opening height and seat diameter ratio, but also for the points can be:

① Weiqi: valve opening height of the seat diameter of 1/20 to 1/10. Figure 2 - 25. Since opening height is small, the structure of this valve and geometry requirements are not as stringent as the entire Kai, design, manufacture, maintenance, and testing are more convenient, but less efficient.

② Tout Kai: hauteur de l'ouverture de la vanne du diamètre du siège d'un quart-tiers.

Soupape de sécurité est dynamique avec l'expansion du milieu gazeux permet de réaliser la vanne montée et déplacement adéquat. Il utilise le siège de soupape et la soupape, les deux bagues de réglage, la soupape de décharge et le support sur les sections de soupape supérieur et inférieur pour former une zone de pression entre la bague, le clapet de soupape à ouverture vers le haut à la hauteur voulue et le rendement requis pression siège. Haute sensibilité de cette structure, l'utilisation de plus, mais la position de la bague de réglage est difficile à régler, utilisez doit soigneusement.

3.Selon la structure du corps de soupape

① Entièrement clos: les médias émissions ne fuit pas, et de laisser aller tous à travers le tuyau de vidange.

② Semi-fermé: les médias de serre, en partie grâce aux émissions du tuyau de vidange, une autre partie de la tige avec le couvercle de soupape et la fuite vers l'extérieur.

③ Ouvert: médias de serre, ne conduisent pas à l'extérieur, directement à partir de l'excrétion de la pétition de la vanne.

 Keywords:butterfly valve ,knife gate valve,ball valve,globe valve,slurry gate valve