- March 29, 2022
- 6:02 pm
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Pressure is the force exerted on a surface, in this case, we refer to the force on a fluid with a single magnitude. In technical terms, it is defined as “the quotient between the normal component of the force on a surface and the area of said surface”.

Therefore, “the force exerted by a fluid in equilibrium on a submerged body at any point is perpendicular to the surface of the body. Pressure is a scalar magnitude and is a characteristic of the point of the fluid in equilibrium, which will depend only on its coordinates”.

Technically it is the force exerted by a fluid in equilibrium on a submerged body at any point perpendicular to the surface of the body. Pressure is a scalar magnitude and is a characteristic of the point of the fluid in equilibrium, which will depend only on its coordinates.

##### Differences between Absolute and Gauge Pressure

That pressure that is found at all times is called “absolute”; on the other hand, the one related to the pressure measured in relation to atmospheric pressure is the “gauge”. It is important to remember that absolute pressure is gauge pressure plus atmospheric pressure.

The density of a fluid is expressed by the relationship between the mass and the volume of a body. Its unit in the International System is the kilogram per cubic meter (kg/m³) and in the English System it is in pound per cubic inch (lb/in³), pound per cubic foot (lb/ft³). This magnitude provides the amount of mass in a unit volume of a substance.

Viscosity can be considered as the internal friction of a fluid, that is, exerting force so that one liquid layer slides over another. It should be noted that the viscosity is higher in liquids than in gases.

*Photo by ESSS*

Likewise, there are more properties of fluids such as: compressibility, specific weight, expansion, which also influence fluids, but everything depends on the specific conditions of each application. It is also important to differentiate the various pressures involved: design pressure, test pressure and operating pressure. Due to the relationship and apparent similarity between these concepts, we make the corresponding distinctions between each one.

**Rating Pressure:** It is the maximum force that will be used for the resistant calculation of the composite parts in the equipment and has to do with the thickness calculations that we define. Everything is done based on an established standard.

**Test Pressure:** It is the maximum internal force that the equipment is subjected to in order to verify, measure and record continuously in a graph with a scale, according to the magnitude established in the Standard, in all the containers subjected to tests. A hydrostatic and/or pneumatic test is proposed.

**Operating Pressure: ** It is defined by the general conditions of each application, depending on what is being produced.

Remember that there are no deficient valves, but rather an incorrect selection of materials. For each application we propose a specific solution, as long as we have the correct operating data, in order to find the solution to the daily situations that are presented to us in the industry.

Do not hesitate to contact us through our usual communication channels. At TYSA de Mexico we have **consulting service ** and trained personnel to design a particular solution for your needs.

## Information Sources:

- Franco, A. (2010). Estática de fluidos. Física con ordenador. Ángel Franco García.
- Equipo ESSS. (2016). Dinámica de Fluidos Computacional: ¿que es?, ESSS.
- Comprende qué es la dinámica de fluidos. (s.f.). El día del maestro.
- Dinámica Computacional de Fluidos CFD, Beneficios y aplicaciones. (s.f.). Prototicad3d.
- ¿Qué significa la presión? (s.f.). Khan Academy.