Because of market trends, production in the fine chemical and pharmaceutical industries can change quickly in terms of schedule, but also in terms of product.

The ability to quickly adapt existing plants to meet new market requirements is a competitive advantage that combines internal project management skills and suppliers’ abilities.

In 2002 Delta delivered a Nutsche filter dryer designed for agricultural intermediates, according to the customer’s specs.

In 2014, after several years of operation, the entire line of production was stopped, and the machine was put on standby. At the end of 2020, market needs called for the production of API and the customer asked Delta to refurbish the machine with this new purpose in mind.



After receiving the Nutsche fiter dryer at its workshop, the Delta team performed the following steps:

  • Assessment of the machine status;
  • Report on the modifications needed to update the machine for API production (including the necessary timeline and costs)
  • Implementation of the modifications approved by the Customer.

Assessment and report

The first assessment involved a review of the original documentation, checking if new installation requirements were compatible with the machine’s original design and features.

After the documental check, the Delta team proceeded with the physical assessment:

  • Visual test, checking for macro deformation or damages.
  • Thickness test, to determine if the thickness of any part of the vessel was reduced due to operation or corrosion.
  • Pressure test, to verify that the vessel worked according to periodical checks required by the pressure equipment directive and relevant standards.
  • Operations tests, assessing movements that the machine should be able to perform (agitator rotation, agitator lifting-lowering, discharge valve opening-closing, etc.)

The documental check found that the filter dryer was designed for a safe area, while the new installation room would be classified as explosive according ATEX Directive (2014/34/EU).

The physical assessment found that:

  • The agitator impeller was totally deformed.
  • The filtering sheet was broken in many places and corroded by the product that remained inside the vessel after the last production.
  • The tightness of the pressure vessel was affected by the failure of old gaskets.
  • The oleodynamic system was damaged in such a way that it was impossible to operate the machine.
Assessment and report


Delta proposed the following actions to put the machine into service for API production:

  • Total surface polishing to attain pharma-grade.
  • Replacement of all gaskets with those suitable for API production.
  • Substitution of damaged parts (mainly the oleodynamic system and filtering sheet).
  • Replacement of the agitator seal with one for a pharma design (a double mechanical seal dry type was selected and installed).
  • To address the issue of the new explosive area in which the equipment has to be installed, all components subject to the mandatory ATEX Directive were replaced so that a new certificate could be issued. In particular, all the agitator driving system, instruments, and sensors were replaced with ones in compliance with installation area classification.


The Delta team was able to take a machine designed for an agricultural intermediate and transform it into an API production one. The process took only 5 months and resulted in a consistent cost reduction compared to a brand-new machine.