Pneumatic

Pneumatic components, systems & spares

Click Here

Lubrication

Centralised lubrication systems & spares

Click Here

Hydraulic

Hydraulic system, spares and components

Click Here

Lubricants

Industrial Electricals spares, components and system

Click Here

Pressure Gauges in Aerial Work Platforms

In aerial work platforms, pressure gauges are used for both hydraulic oil pressure indication and as a test gauge for maintenance. Hydraulic oil pressure gauges are typically mounted in the aerial work platform’s operator control panel and tied into low-pressure annunciators that alarm the operator in the event of a hydraulic fluid leak, a low oil level in the reservoir, or a failure of the hydraulic pump and associated control valves. For maintenance, hydraulic oil pressure gauges are part of the serviceman's tool kit and used to check oil pressure after the replacement of hydraulic component or to assist in the setting of the main pressure relief valve. It should be noted that pneumatic pressure gauges are also used in aerial work platforms. These pressure gauges are used to check the platform’s tire pressure, which is an important safety concern.

Types of Pressure Gauges

There are numerous types of pressure gauges, which are suitable available for any application, pressure range or ambient condition. To select the correct pressure gauge, one must consider accuracy, pressure range, material, dial type and connection size. The main types of pressure gauges that could be applied in aerial work platforms are the general-purpose bourdon tube, capsule-type, and differential pressure gauges. The general-purpose bourdon tube gauge is constructed with a C-Bourdon tube formed in a circular arc. The bourdon pressure gauge is named after Eugene Bourdon, the man who invented it in 1849. The bourdon tube pressure gauge found widespread acceptance and was widely adopted because of its above average sensitivity, linearity and accuracy. It works on the principle that the C-shaped tube will try to straighten itself as pressure is increased. Since there is a difference between in the inner and outer radii of the tube, a rotational motion occurs which drives a pointer to indicate pressure. Bourdon tube pressure gauges can be designed to operate up to 20,000 psi. The capsule pressure gauge consists of two plates welded together. Applied pressure causes the capsule to contact or expand which drives the pointer to indicate the pressure. These pressure gauges are used for low to medium pressure applications. Differential pressure gauges compare two pressures and indicate the difference between them.

Liquid Filled Pressure Gauges

A common pressure gauge used in aerial work platforms is the liquid filled pressure gauge. They are based upon the operation of liquid column gauges, which are constructed with a U-shaped tube and each end of the vertical legs of the tube are exposed to different pressures. As the pressure changes, the liquid in the column will increase or decrease in height until a pressure statis occurs. The difference in the height of the two columns is analogous to the applied pressure. These pressure gauges are typically bourdon tube pressure gauges. The gauge is usually filled with glycerin although silicon is used for low temperatures or excessive temperature changes. They are ideal for continuous readings in pressure ranges up to 3000 psi. One of the primary benefits of liquid filled pressure gauges is the inherent dampening characteristic that they possess. They can absorb vibrations and prevent the gauge’s pointer from vibrating excessively, which extends the service life of the gauge.