With turnaround valves, is more exact with those designs that approach directly according to the name more, we stopped to get acquainted in last article. Now we will get acquainted with other version of turnaround valves which are called besides turnaround locks. As we remember, a saddle axis in turnaround valves is usually perpendicular to the direction of a stream of a working environment. In turnaround valves the saddle axis, usually, coincides with the direction of a stream of a working environment. This main constructive difference.
Fig. 1. Scheme of work of a turnaround lock.
The main locking device of a turnaround lock is called захлопка, on fig. 1. it is designated by reddish color. The axis that захлопки which that fastens to the case, takes place usually above a saddle. Therefore, when the stream of a working environment achieves a certain force, захлопка reveals, and does not disturb a clot. When the stream is lost, захлопка is locked under the weight. If the stream of a working environment changes the direction, захлопку simply does not reveal. As though everything is very simple, but that technology has also a significant defect.
Hardly we will face with such неуввязками at household use, but for big pipelines discrepancy exists. The weight захлопки in such systems big, and from blow the locking mechanism completely can fail. In certain situations even there is a danger of hydroblow at operation.
Therefore, all turnaround locks share on ordinary and unaccented. Ordinary locks are used for pipelines by a diameter to 400 mm. As you realize, is concrete with ordinary to us and it is necessary to face in a life.
Fig. 2. Look захлопки turnaround lock.
Unaccented turnaround locks it is more difficult designs. The purpose of that complication to break fall захлопки to make its movement by smoother. There are different decisions. For example, special hydraulic dampers which can directly be established on захлопку are used. Can use and cargoes which too can be established both on itself захлопку, and with lever introduction. Not including difficulties such designs can impose and the next restriction, it is possible to establish them only on horizontal sites.
Continuation follows …
