JA-3 Shear pin safety valve,apply to high pressure water jet drilling rig which promotion of universal now.also can be used on other high pressure circulatory system of the other medium like oil,water. Compare with spring tpye and diaphragm type, this valve has some features as below: 1. quick switching; 2. area of pressure pistons small; 3. replacement easy; 4. good universality,can be connected with various types of pumps.