Delta (Δ) is the fourth letter of the Greek alphabet, is used as a mathematical symbol and describes the difference of any variable quantity.
Examples of quantities are:
P is the formula symbol for the physical pressure. Pressure indicates the force exerted by a body on a surface. Pressure is expressed in pascals (Pa). When these two pieces of information are combined, it is understood that delta p (Δp) stands for pressure difference.
Use of delta p (∆p)
Delta p (∆p) thus describes the pressure difference between two measured values. These values can be measured at different times or at different locations in a system. Three situations can be recorded:
- The pressure has not changed, it has remained the same.
- The first value is smaller than the second value — pressure increase
- The first value is greater than the second value — pressure drop.
Calculation of delta p (∆p)
∆p = p1 — p2
Practical examples of delta p (∆p)
Pressure differences can be measured in many areas. Typical examples are the pressure drop in a piping system — for example before and after a tool, a heat exchanger, a pump or a filter. A small pressure drop in these examples is due to wall friction in the systems.
Unintended pressure differences
Delta p (∆p) is an important measurement of the quality of pressurized systems. Unintended changes in the pressure structure quickly have a negative impact on the functions in the system and should be noticed and corrected as soon as possible. For quick verification of pressure differences, data loggers can be used to record changes in the circuit and provide conclusions about the problem.« Zurück zum Glossar Index