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高压釜上的针阀,无论是国产的还是进口的,其密封结构基本相同,即阀尖和阀杆设计成一体,阀杆上带螺纹,通过手轮旋转阀杆,使阀尖旋转前进,挤压阀座,从而起到密封的目的(图1)。这种结构的针阀,对中性要求高,关闭时阀尖和阀座之间有强力的相对挤压和旋转,产生很大的局部摩擦力,加之为了防止介质对针阀的腐蚀,一般采用屈服极限较低的耐酸不锈钢材料制作,因此密封带(面)极易磨损擦伤,甚至发生粘结,密封很快失效,稍有泄漏,就得使劲旋紧阀杆,结果是泄漏越来越严重,只好更换新阀。
Needle valve on the autoclave, whether domestic or imported, the sealing structure is basically the same, that the valve tip and stem design into one, the valve stem with a thread, through the hand wheel to rotate the valve stem, the valve tip rotation forward, Squeeze the valve seat, which played a sealed purpose (Figure 1). This structure of the needle valve, high demand on the neutral, close the valve tip and seat between the strong relative extrusion and rotation, resulting in a great local friction, coupled with the media in order to prevent the corrosion of the needle, the general Made of stainless steel with a lower yield point, the sealing band (surface) is extremely abrasive and scratches, even sticking. The seal quickly fails with a slight leak, and the stem tends to tighten. The result is a leak The more serious, had to replace the new valve.