Pressure Guage

                                               What is Pressure Gauge.

A pressure gauge is a fluid intensity measurement device. Pressure gauges are required for the set-up and tuning of fluid power machines, and are indispensable in troubleshooting them. Without pressure gauges, fluid power systems would be both unpredictable and unreliable. Gauges help to ensure there are no leaks or pressure changes that could affect the operating condition of the hydraulic system.

The hydraulic system is designed to work in a set pressure range so the gauge must be rated for that range. Hydraulic pressure gauges are available to measure up to 10,000 psi, although maximum hydraulic pressure is typically in the 3,000 to 5,000 psi range. Hydraulic gauges are often installed at or near the pump’s pressure port for indication of system pressure, but can be installed anywhere on the machine where pressure needs to be monitored—especially if sub-circuits operate at a pressure rate different from pump pressure, such as after a reducing valve. Often, pressure-reducing valves have a gauge port to tap into, allowing you to directly monitor its downstream pressure setting.

Pressure gauges have been used in fluid power systems for well over a hundred years, so it might be a surprise that pressure gauge designs continue to evolve. The evolution of pressure gauges for fluid power applications has, generally, been an increase in application specific features. For instance, pressure gauges are now more routinely designed with hydraulic friendly pressure connections (such as SAE/Metric straight threads) to prevent system leaks. Analog gauges with custom scales are more common and digital pressure gauges with customizable firmware allow process measurement of pressure-based measurement of leaks or other parameters like torque, load, force and hardness.

Pressure gauges have been used in fluid power systems for well over a hundred years, so it might be a surprise that pressure gauge designs continue to evolve. The evolution of pressure gauges for fluid power applications has, generally, been an increase in application specific features. For instance, pressure gauges are now more routinely designed with hydraulic friendly pressure connections (such as SAE/Metric straight threads) to prevent system leaks. Analog gauges with custom scales are more common and digital pressure gauges with customizable firmware allow process measurement of pressure-based measurement of leaks or other parameters like torque, load, force and hardness.

Bourdon tube operation is simple. They consist of a semicircular and flat tube of metal, fixed at one end and attached to a sensitive lever mechanism at the other. As pressure increases inside the tube, the force of the fluid attempts to straighten out the curved tube. The tube then pulls away from the lever, which being connected to the needle on the display, shows the pressure at the fluid port.While bellow gauges function similarly to Bourdon tubes, they differ in the fact that they use a spring to judge the amount of energy to push the dial. The spring is expanded and compressed by the pressure in the tubes and the energy created by that movement is transferred into gears that move the pressure dial.

Most pressure gauges in North America come with a 1⁄4-in. NPT male, but SAE thread is gaining popularity. The use of test-point adapters at various locations on the hydraulic system allows for measurement during troubleshooting without having to purchase dozens of pressure gauges. The test-point fitting attaches to the gauge, which can be screwed onto the test points throughout the circuit, allowing you to connect under pressure to measure at various points in the system. Most gauges are 21⁄2 in. in diameter, and can be either top-mount or panel-mount styles, but gauges are available in every size, material and construction imaginable.