Polyol and Isocyanate

Polyurethane is used in a wide range of applications to create various consumer or industrial products and in the production of various common use objects. It is also widely used in the construction sector as insulation and in sandwich panels.

Polyurethane is obtained by mixing two main materials, polyols and isocyanates. Belli Meccanica produces reliable and specific pumps for the polyurethane industry for pumping these two raw materials. The pumping of the polyol does not require any particular precautions, it is an oily liquid of medium viscosity, which has no tendency to get solid or catalyze.
The pumping of isocyanate, on the other hand, presents many critical issues due to the fact that it easily gets solid in contact with air and humidity and, moreover, it’s inflammable and toxic. For pumping isocyanate the pumps with external seal L series or the magnetic drive pumps MAG series are widely used, both in Atex version for zone 1. In the first case the pump must be equipped with double tandem or cartridge seal and pressurization barrel with barrier liquid according to the API Plans, so that the faces of the mechanical seal work with the barrier liquid used and do not come into contact with the isocyanate.

A simple mechanical seal is in fact not very reliable since the isocyanate is easily subject to solidification with consequent leakage of the seal. In the case of MAG magnetic drive pumps instead, the pump is sealed thanks to the use of the magnetic coupling that avoids any risk of leakage. In both cases, thanks to its decades of experience in the polyurethane sector, Belli Meccanica is able to offer reliable solutions focused on the particular application.