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前言螺栓是电厂中重要的紧固另件之一。它起着使汽缸法兰、阀门、管道法兰等汽密的重要作用;它紧固的好坏直接关系到生产及人身的安全。正由于此,有些电厂在紧固螺栓时认为紧力越大越好;同时在紧固方式上一般都用大锤猛击搬手。由于螺栓位置的不同,用力极为不均,再则人的锤力亦不同,这就使得同一阀门上各个螺栓的紧力相差很大,有的已接近屈服值(1)。这就造成断裂事故相当频繁,尤其是调速汽门的螺栓,断裂的几率比别的大。目前有的电厂在紧固工艺上正在逐步改革原有的方式—如用风动板手等,但这仅仅是使同一法兰上的各螺栓紧力达到较均匀的水平。究竟达多大紧力能使法兰既汽密而螺栓又不断或少
Introduction Bolts are one of the important fastening parts in power plants. It plays an important role in making the cylinder flanges, valves, pipe flanges and other gastight; its fastening is directly related to the production and personal safety. Because of this, some power plants consider the tightening force as large as possible when tightening the bolts; meanwhile, sledgehammers are commonly used for the fastening method. Due to the different bolt positions, the force is extremely uneven, then the human hammer is also different, which makes the same valve on the bolts of a great difference between the force, and some close to the yield value (1). This resulted in a very frequent fracture accidents, especially the speed control valve bolts, the probability of rupture other than large. At present, some power plants are gradually reforming their original methods of fastening technology - for example, using wind-driven wrenches and the like, but only to achieve a more even level of bolt tension on the same flange. After all, how tight can the flange be both dense and bolted and less or less