Pit or Bell

As with a muffle, this element confines the active atmosphere and the static charge during the treatment. Heat treatments are frequently of the case-hardening, carbonitriding, quenching, annealing and normalising type. The stresses are thermal in the heating zone and mechanical where the load is supported. The alloy must be adapted to these stresses.

We can offer you replacement or repair services, and we are able to reproduce any type of bell or vertical furnace pot made in boiler making, from the simplest to the most complex.

Our sales, technical and administrative teams are on hand to provide you with the pit (or bell) best suited to your real needs.


The plug is the oven’s “door”, in permanent contact with the high-temperature interior and exterior. It provides thermal insulation, and most of the time acts as the furnace’s management interface, with its gas injection and atmosphere control nozzles, and its atmosphere mixing turbine driven by an electric motor and channelled by a convection cone. In some cases of vertical bell furnaces, a lower plug supports the load (base or sole).