Polymer as a component of the composite component of the cover of a communication manhole has been used relatively recently. Well-chosen alternative materials can resist well the negative factors of exploitation. But, nevertheless, cast iron sewer hatch still enjoys stable consumer demand. There are very good reasons for this.
What loads does the hatch face?
Even the iron cover of a sewer well will not be able to withstand the load created by transport, if it is initially incorrectly selected. There are several classes. Each of them is designed for a certain dynamic and static load in tons:
- L (A15) - designed exclusively for pedestrian areas, withstand up to 1500 kg.
- С (В125) - up to 12.5 tons, parking lots, park area, sidewalks where vehicles can exit.
- Т (С250) - a hatch for standard roads, city streets with a load of up to 25 tons.
- TM (D400) - main roads with heavy freight traffic up to 40,000 kg.
- ST (E600) - highly specialized manhole covers with a load of up to 60 tons.
Classic cast iron has stable characteristics, they do not depend on temperature drops and service life. The significant thickness of the material allows the product to be in the worst conditions for tens of years. The fragility of the material can manifest itself only in the case of a defective hatch, when it does not fit snugly, and constantly vibrates during a collision of the truck's wheels. To the conditional disadvantages of a composite polymer material, you can add:
- under the influence of strong temperature changes, the polymer may be brittle or bend;
- direct sunlight gradually destroys the structure of the plastic;
- chemically active vapors have a negative effect on the polymer component;
- a plastic sunroof may gradually sag due to heavy traffic.
For the sake of fairness, it should be added that a polymer replacement for cast iron can be used on a personal plot. An affordable analogue harmoniously combines with the lawn, if it has a green color.