The fans complex (high pressure fans) C7-15-1750, C7-22-1750, C7-15-750, C8-27-1450 are products of the manufacture of a single individual production. So maybe a lot of options and versions of units.
Fan Installation intended to supply air (or gas) at a relatively high, — (compared to conventional parameters of fan) pressure at elevated temperature. Can be used for organizing accelerated drying paper, textiles, granular fertilizers, peat, sand, clay and other similar cases. For these reasons, the fan complex requires a very large capacity drive, and also has its own characteristics, which defines it as the product of individual production.