When the O-ring has relaxed to grasp the shoulder protection, the bonnet assembly may be assembled into the body with the O-ring clinging to the back-up washer.

• 当放松O形环使其恢复原状，此时O形环就抓紧肩部保护，带着粘附着后部垫圈的O形环，阀帽组件可以组装进阀体内。