How Does a Liquid Pressure Gauge Work?

Identification

Liquid pressure gauges are used in a variety of applications and settings. Industrial environments where coatings and sealants are applied on a regular basis rely on a gauge's readings to ensure safety guidelines are being met, and application amounts are per specifications. Gauges are manufactured to meet certain guidelines, as put forth by the American National Standards Institute, or ANSI, and are designed to different accuracy readings, depending on the application type. Liquid pressure gauges can provide needed information when a machine malfunctions, allowing operators to attend to the problem before more serious problems develop. A second type of pressure gauge, called "Traditional," may also be used in industrial applications, however, the liquid-type gauges are the preferred device. The design of the liquid gauge makes for less wear and tear, fewer problems with condensation and back-up, as well as a longer lifespan.

Function

A liquid pressure gauge's primary job is to maintain a machine, or process fluid system dynamics, and to ensure spray nozzles, pumps and related components are all working properly. The central feature within the device is called a Bourdon tube. It is a hollow tube that sits in a coiled-oval shape inside the gauge. As pressure increases inside the tube, the tube begins to uncoil. The tube itself is connected to a gear system that turns the needle on the dial. The tube is designed to expand and uncoil in proportion to the amount of pressure that enters it. As this happens, the needle on the gauge moves accordingly. Any pressure changes that take place will be reflected in the needle's movement. The gauge itself measures static as well as dynamic pressure, which indicates conditions when fluids are stationary, as well as pressure levels when fluids are moving.

Effects

Liquid pressure gauges are filled with certain types of liquid oil to help absorb vibration and high pressure conditions. This aspect of its design helps to reduce wear and tear on the more delicate parts of the device. Glycerine and silicone are the standard fill fluids, with silicone being most effective under extreme temperature changes. The liquid contents also helps to reduce water condensation build-up inside the gauge, which is one of the most common problems encountered in using gauge devices. Added accessories which can be used to further prolong the life of a gauge device include a shutoff valve, which blocks off the device from the machine process during maintenance checks. To further reduce damage incurred from vibrations, or extreme temperatures, pipe coils and pulsation dampeners are used. These accessories are designed to absorb pressure fluctuations and spikes in pressure readings.

Resources

• Pressure Gauge Components