Why the hatch is round
Why the hatch is round
To the covers of sewer hatches are madeserious requirements - they must weigh at least 50 kilograms, have a surface with a relief of 2 to 6 mm, have special structural elements for easy removal and a hole to check the gas contamination of the sewage system. However, there are no norms for the form of hatches, nevertheless in most cases they represent a circle.
Instructions
1
The main reason why the lidssewer hatches made round, is that their production requires less material. The norm of the width of the sewer is 600 mm, that is, the round hatch cover should have a diameter of 600 mm, and the square one - the side of 600 mm, with such dimensions the area of the square hatch cover will be 0.36 m2, and the round one only 0.25 m2, 28% less.
2
The round cover will not only be smaller in area, but also thinner, since in it the loads are distributed evenly, which means that the requirements for strength are reduced.
3
Rectangular or triangular covers canaccidentally fall into the hatch, get them because of the heavy weight will be problematic, they can damage the equipment or cause injury to the person in the fall. The round lid will not fail in any way to the hatch, suitable for its size. Sometimes the hatches are made in the form of a Raelo triangle, which is also called a round triangle, such a triangle also does not pass into the hole, since it has a constant width.
4
The round hatch cover is easier to install, it always gets in place. It does not need to be rotated properly, so as to hit the corners exactly as it would be with the cover of any other shape.
5
Round hat covers have smaller lengths of supporting parts than rectangular variants, which means that the risk of rejection is reduced. Covers with protrusions or recesses on the supporting parts quickly break down and clap.
6
Controversial is the contention that the lidshatches are round because they can be rolled so they can not be carried. The round caps have special support projections, so it's impossible to roll them all the same, on the other hand, to move such a cover a few dozen centimeters is really much easier than rectangular.
7
Round hatches almost neversag, but rectangular sag almost always. Finally, the sewer shafts are more often round, so it's logical to make a lid for them round.
