Self-sealing manhole cover for bulk loading powder tank truck

Abstract

The invention discloses a self-sealing manhole cover for a bulk powder tanker. The manhole cover is mainly composed of a manhole cover ring assembled and welded together, a top cover and a fixed pressure plate, and a rubber ring fixed under the fixed pressure plate through bolts, nuts and pressure rings. The rubber ring is composed of an upper airfoil with a rectangular cross-section, a rectangular side elevation with a rectangular cross-section, and a lower airfoil with an equal-thickness cross-section and an outer extension edge. The overall cross-section of the rubber ring is in an inverted J shape. The upper airfoil and the side elevation are connected at right angles, the side elevation and the inner side of the lower airfoil are connected by reinforcing chamfers, and a sealing convex is arranged under the end of the inner side of the lower airfoil. edge. The outer extension edge of the lower airfoil is in the shape of turning outwards and upwards at right angles, and the tight hoop fits on the bottom of the manhole cover and the outer lower wall surface. It has high rigidity and strength, good sealing effect and high pressure bearing capacity, and is especially suitable for application on railway bulk powder tank cars.

Description

technical field [0001] The invention relates to manhole equipment on a bulk powder tanker, in particular to a self-sealing manhole cover for a bulk powder tanker. Background technique [0002] At present, most of the manholes on the bulk powder tank cars of my country's railway vehicles still adopt the traditional self-sealing form, which has a history of more than 30 years. Its structure is mainly composed of a manhole seat and a manhole cover. The manhole seat is welded by a manhole seat ring and a cover ring, and welded on the tank body. The manhole cover is composed of a manhole cover ring, a top cover, a fixed pressure plate, a sealing ring and a pressure ring, etc., and the sealing ring is fixed on the fixed pressure plate with bolts and nuts by the pressure ring. One end of the manhole cover is connected to the lug of the manhole seat through a revolving pin, and can rotate around the revolving pin. When the manhole cover is closed, the other end is pressed tightly ...

AI Technical Summary

Problems solved by technology

[0004] But above-mentioned manhole cover still has some deficiencies: when the pressure in the tank is lower than a certain value, just can't make the manhole well seal

The actual situation is: because the end of the lower airfoil is very thin, it is easy to wrinkle when the rubber ring is formed, so that there is almost no bonding force

When the cover ring and the lower part of the side elevation of the rubber ring are in contact, the end of the lower airfoil is often upturned and does not fit at all, so it is often easy to leak air when the pressure in the tank is low

When the pressure in the tank increases to a certain value, and because the lower wing surface is too thin, it is easy to squeeze out from the gap between the manhole cover and the cover ring, causing a large amount of gas to be discharged from the tank.

At the same time, limited by the original structure, the design rigidity and strength of the traditional manhole cover are not sufficient, and permanent structural deformation may occur during use, which is also the reason why the rubber ring is easy to be squeezed out during the manhole hydraulic test

In addition, the rubber ring is fixed on the fixed pressure plate by the angle steel pressure ring, and its pressure surface is in a wavy shape after forming, and its side is difficult to ensure verticality. Therefore, it not only increases the difficulty of sealing the end of the rubber ring's lower airfoil, It also does not play a good supporting role on the side elevation of the rubber ring

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