The article presents a general algorithm for studying the technical state of drain valve of tank-wagon. The author of the article also demonstrates the construction of drain valve, the requirements of regulatory documents to it. The main list of works that must be carried out when examining the technical condition of the drain valve of a tank-wagon is established. Among them, the most important is the establishment of the correspondence of the number of the tank wagon to the number given in the materials provided for investigation, of all the repairs that were carried out by this wagon and the terms when there had to be done.
It is also noted that it is very important to check the presence of stamps of the upper filling hatch and the drain valve of the tank-wagon when inspecting the exterior. The next is to inspect the bottom cover and the drain valve bracket. It is important to investigate whether the rubber seal of the lid does not have deformations or ruptures, the clamp – deformations, cracks, fractures.
The author of the article notes that in order to better study the drain valve, it must be dismantled from the tank. When inspecting the valve O-ring, it should be installed or does not have deformations or ruptures. After this, it is necessary to check the presence of all drain valve pins holding its clamping ring. Particular care should be taken to examine the lower feathers of the tank valve, since there may be signs of interference with the operation of the device.
When inspecting the parts of the drain valve inside the tank, it is necessary to examine the condition of the valve stem thread for damage, breakage of the turns, visually inspect the frame, the bar to detect such faults as deformations (bends), cracks, breaks. In addition, when inspecting the frame, it is necessary to establish the presence of all bolts of its attachment to the boiler.
After this, it should be scrolled the handle of the rod and the cover screw. When you open the drain valve, you need to investigate whether it is skewed when you open it. Particular care should be taken to examine the lower feathers of the tank valve and ascertain whether there are any traces of foreign objects on them.
The author of the article describes the sequence of checking the tightness of the drain valve to the tank.
It is rightly noted in the article that from the technical point of view, access to the cargo that is in the oil product tank through the lower drain valve can be achieved by unscrewing the lower cover (additional shutter) and pressing the valve (main shutter), that is, applying a mechanical force.
In this case, the feathers of the drain valve will show signs of foreign interference, and the bar will be deformed. In the article it is noted that the investigation of the technical condition of the tank drain valve is a rather complicated and laborious process. But, in turn, the above information is collected will bring some clarity when establishing the technical state of the drain valve of the tank-wagon and will allow to solve the main task of the forensic railway transport expertises – the disclosure of its mechanism.