The engineer Carlo has taken into account the Standard for the manhole covers choice but not other fundamental aspects. Read the case study.
The loading class
Projects

Necessity
Engineer Carlo needed to place some manhole covers on a very busy high-speed road near Sassuolo. The request sent to Fonderie Belli was for a supply of 300 manhole covers in D400 class which is the minimum loading class for roads carriageways (including pedestrian streets, docks and parking areas, for all types of road vehicles).
Solution
Fonderie Belli proposed to Eng. Carlo a customized price for the specifically requested products and the supply was successful thanks to the quality of Fonderie Belli’s products.
Problem
After a couple of months, the Institutional Body that had contracted the job, contacted Eng. Carlo to solve the problem because the manhole covers started to loosen from the road surface between two specific road exits.
Eng. Carlo immediately called Fonderie Belli to report the fact, asking for clarifications about the supplied cover.
Problem Solving
The price of the manhole covers, especially for large supplies, is calculated by weight (Eur/kg) and therefore, it is usually used to require the minimum load class for that installation, following the standard, without taking into consideration other factors that could affect the performance of the manhole cover. In this specific case, Eng. Carlo did not consider that particular stretch of the road is daily traveled by a huge number of trucks that move goods from one company to another in a joint production cycle.
The solution would have been to install D400 class manhole covers, as required by the Standard, for the entire high-speed road and, between the two specific exits, to install top-quality manhole covers in order to save on future maintenance costs.