From Fluid Handling

Pristine processing, where high purity and contamination control are extremely important, is a familiar concept for pharmaceutical production and microelectronics fabrication. Increasingly, it is also an issue for the manufacture of agricultural and fine chemicals, and in environmentally sensitive processes. Regardless of the application in the chemical process industries (CPI), the approach to valve selection when clean processing is involved is very different from that taken when purity requirements are not as stringent, or are nonexistent.

Compared with other applications where valves are used, clean processes typically have three major distinctions:

  • Different types of valve are used
  • More valve are used
  • More valves are actuated and
    automatically controlled

An assortment of valves
In contamination-sensitive processes, the first step is to select valves that do not harbor trace amounts of contaminants, and are easy to clean. In the pharmaceutical industry, for instance, the diaphragm valve is generally regarded as the only choice for a generalpurpose valve in process fluid applications. Why? Because it has no crevices or recesses to harbor contaminants, and, when open, it exposes only smooth, gently curved surfaces that are easily cleaned. When closed, it squeezes product out, so as not to trap significant amounts of residue in...


More >>
© 2014 Chemical Engineering

Products & Services
Double Diaphragm Pumps
Double diaphragm pumps are positive displacement pumps that compress fluid by decreasing the volume of a chamber containing the fluid.
Hand Pumps and Foot Pumps
Hand pumps and foot pumps are manually operated pumps that can driven by hand or foot via a handle or lever. 
Mechanical Vacuum Pumps and Systems
Mechanical vacuum pumps and systems contain devices such as pistons, claws, scrolling spirals, and diaphragms to isolate and compress air.
Condensate Pumps
Condensate pumps are used to collect and transport condensate back into a steam system for reheating and reuse, or to remove unwanted condensate from an HVAC or appliance collection pan.

Topics of Interest

It is intuitively obvious that lowpressure (vacuum to 15 psig) petroleum- product storage tanks need normal and emergency venting. Most of the design details have been incorporated into the standard...

Many industries require equipment that meets specific design and construction criteria to ensure "sanitary" conditions. Here, "sanitary" does not refer to waste treatment applications but to highly...

Tetra Pak Carton Chilled Inc., Minneapolis (tetrapakusa.com), recently introduced a new Gable Top Liquid Carton filling machine that incorporates cleandesign pneumatics to ensure washdown resistance,...

When it comes to pumping high-purity fluids, not any pump will do. Processors of pharmaceuticals, foods and beverages and biological compounds must consider pumps in ways that may not be particularly...

A comprehensive inventory for sanitary standards and accepted manufacturing practices for the dairy, beverage and food processing industries has been established by 3-A Sanitary Standards Incorporated...