Terminology - P

  • PARALLELISM: The relationship of surfaces in different planes. To be parallel, the planes passing through the surfaces must be in the middle of each other at all points when measured at 90° to the planes.
  • PENSTOCK: A gate used to regulate the flow of water, or a channel used for conveying water to a waterwheel or turbine.
  • PIECE: The portion of the sample that is prepared for testing.
  • POLYISOPRENE: See Natural Rubber.
  • POROSITY: The prescence of numerous small cavities, or open spaces, in the product.
  • POST CURE: A second cure that is sometimes given to products after an original shaping, or preforming partial cure.
  • PREFERRED NUMBERS: The conventially rounded off term values or geometric series that includes the integral powers of 10 and has ratios with the following factors: 5√10, 10√10, 20√10, 40√10, and 80√10.
    Source: International Standards Organization (ISO) Recommendation R-3, Preferred Numbers.
  • PUMP STATION: A plant built with diesel or electric powered pumps to move water for drainage or storage. Such stations are also built to move sewage to a treatment plant.