The case passed number 6 in this series of articles, and itself on for itself number quite good. Therefore, we now will return it, but we will hold in the head what to read the sixth article better after article number seven. We will begin more detailed acquaintance to safety fittings with a safety valve. Designs of such valves can be various, we about it still will have a talk, but the mechanism of their work is very similar. On рис1. The scheme of work of a safety valve is represented, is more exact than the ordinary spring valve of direct act. What is the valve of direct act, we already made out in previous article, just in case I will repeat. The valve of direct act, it means that he defines an emergency without additional devices and intervention of the person, and itself solves measures for its elimination.
Fig. 1. Scheme of work of a safety valve.
Important element of a safety valve is the zadatchik, in other words an element which has power impact on a sensitive element which is in turn connected with locking body of the valve. In the provided scheme a zadatchik is the spring. Zadatchik is adjusted so that in usual criteria the locking body interfered with passing of a working environment. In our case it becomes by means of the special screw. A locking element in our case are the zolotnik and a saddle.
That safety valve simply works. When pressure of a working environment in norm, occurs nothing. But here, when pressure becomes more norm that can be unsafe for system, pressure of a working environment upon locking body grows, and when pressure force becomes not less pressing force of a zadatchik, the locking body starts to reveal. It is clear that during this moment there is a dumping of a working environment.
Fig. 2. Safety valve.
From dumping there is a pressure drop in system. When pressure of a working environment will fall down to norm, the locking element under the influence of pressing force of a zadatchik again will be closed. Here approximately and works though what safety valve. It is necessary to emphasize that we made out the best option, in a number of every possible cases closing of a locking element needs effort therefore pressure of a working environment should lower for 10-15 % below the usual.
Continuation follows …