Valves in action ─
Pressure reducer DM 152
Control of pure steam for vaccine production
The production of water of outstandingly pure quality for pharmaceutical applications is subject to strict regulations in the relevant pharmacopoeias. In general, a limit of max.10 microorganisms per 100 ml applies for colony-forming, anaerobic germs.
For medicinal preparations, the values can also be stricter, especially in the production of parenterals, i.e. the solutions for infusions or injections, such as vaccines. Water for injection (WFI) must be mixed with components that make the solution isotonic before use. If this is not done, the cell membranes of the red blood cells would not withstand the pressure of the water exposure during an infusion and would burst.
WFI can be produced by reverse osmosis or via distillative methods. A large Asian biotechnology company is a contract manufacturer for a leading vaccine producer and manufactures WFI for them using the multiple effect distillation process (MED).
This process follows the physical law that the particles and impurities to be separated remain in the water via the phase transition from water to steam.
TASK // Control of pure steam in multiple effect distillation
A pressure decline is set between the evaporator stages of the MED plant. The feed water is evaporated in the first column with the aid of external energy. This is where the maximum pressure is reached. The pure steam thus generated condenses on the shell side of the condenser. The released heat evaporates part of the feed water and generates further pure steam. By the time the last column is reached, the temperature has dropped to approx. 100 °C. The pure steam produced here is then condensed in the condenser with the aid of the counterflowing feed water. In the multi-column plant, the DM 152 pressure reducing valve regulates the high-purity steam at approx. 150 °C from approx. 3 - 3.5 barg to 1.3 - 2 barg.
SOLUTION // Pressure reducing valve DM 152 of stainless steel
The DM 152 stainless steel pressure reducing valve has excellent resistance to the aggressive steam atmosphere. Thanks to its superb surface finish and the Mankenberg clamp system, it is easy to clean and maintain. The non-rising adjusting screw ensures an unchanged overall height, so that the valve can be integrated precisely into the MED plant. The deep-drawn stainless steel valve components have minimal mass, resulting in low heat loss in CIP/SIP applications. The elastomers comply with the strict USP Class VI regulation of the United States Pharmacopeia (USP). The PTFE protection film can be steamed up to 180 °C. These advantages convinced the Asian biotechnology company to install the DM 152 pressure reducer and other Mankenberg valves in its ultra-modern plant.
