High pressure processing equipment is used to treat foods, beverages, proteins, enzymes, and other bioactive materials. Products are subjected to high pressures with or without the addition of heat to inactivate microbes and bacteria. An alternative to thermal processing, high pressure processing (HPP) subjects products such as packaged foods to pressures as high as 100,000 pounds per square inch (psi) to destroy pathogens without diminishing product quality. Often, high pressure processing equipment is used to destroy Listeria, E. Coli and Salmonella and other food-born pathogens without affecting attributes such as taste, appearance, texture and nutritional value. There are many different types of high pressure processing equipment. Typically, the food, beverage or other bioactive material is packaged in a flexible container such as a pouch or plastic bottle and then placed into a pressurized chamber filled with a pressure-transmitting fluid. A pump is used to pressurize this hydraulic fluid, usually water. The pressure is then transmitted through the packaging to the product itself. After a specified period of time, typically between 3 and10 minutes, the product is removed and stored. Because pressure is transmitted simultaneously and uniformly, high pressure processing equipment allows packaged foods to retain their shape. High pressure processing equipment differs in terms of scale, size, orientation, approvals, applications, and features. Product specifications include maximum vessel pressure, inner vessel diameter, inner vessel height at maximum pressure, and temperature range. Both laboratory scale and production scale systems are available. For production equipment, the cycle time or production rate is an important consideration. HPP system components such as the intensifier pump, water module, and vessel temperature controls carry their own specifications. Choices for high pressure processing equipment orientation are vertical or horizontal. High pressure processing equipment is used for high pressure food preservation, high hydrostatic pressure processing (HPP) and ultra high-pressure processing (UHP). The food processing industry uses HPP systems to produce safer, fresher, more natural, and better tasting foods. In some cases, the shelf life of packaged foods can be doubled with HPP. In addition to chicken strips and other meat items, HPP equipment is used to sterilize fruit, vegetables, deli salads, seafood, and other ready-to-eat products. Because many bacterial spores are resistant to commercially-available pressures, these food products typically require chilling or refrigeration after high pressure processing equipment is used.