The Pressure Switch as a Safety Mechanism
Workplace health and safety is ever more prominent in many industrial workplaces with risk assessments and safety seminars being regular occurrences in most companies and governmental organizations. There are also many different safety mechanisms within these workspaces, which help to ensure personnel protection by reducing or eliminating hazards. One often unnoticed safety device in many workplaces is the ‘pressure switch‘.
A traditional electrical switch is generally defined as a device utilized to interrupt the flow of electrons in a circuit. A pressure switch acts in much the same way as a traditional switch however, it is usually ‘triggered’ via a specific change in pressure, which can stem from either gas or liquid. As with regular switches there are also two standard states in which a pressure switch can exist: ‘on’ (closed) or ‘off’ (open).
The Role of the Pressure Switch Regarding Safety
One of the main roles of these switches in many industrial workplaces is basically to sense when a vacuum or pressure moves out a defined range, and to either shut the power off or sound an alarm. This is needed, as pressure during some industrial processes may rise (or fall) to a level that can damage equipment, or more importantly personnel.
A simple example of this is an industrial air compressor which utilizes a pres. switch to stop the electric motor when the tank reaches the desired pressure. Without this switch the air tank could exceed the labeled pressure rating, which could result in components being damaged, or the entire tank exploding. In a similar, however more complicated fashion, these switches also control the air breaks on industrial equipment such as trains and large trucks.
Unbeknownst to many civilians however, these types of switches can also be commonly found in everyday home and office settings, with a good example of this being a lift in a multistory building. Many lifts are operated by hydraulic pressure which previously meant that a breach in a hydraulic cylinder or other such issue could send a lift hurtling to the bottom of the chamber. Pressure switches now exist however, that are able to constantly monitor hydraulic systems and cut power to the lift if the pressure falls under 1200 psi.
Noting the mix of residential and industrial utilizations of these devices, it is easy to understand why one of the issues with the use of pressure based switches as safety devices in the past, has been the selection of the right switch for the right application. This owes mainly to the fact that, whilst residential applications rarely need to be exact, industrial switches in comparison must display a high level of dependability and accuracy. Recent advances in technology however, have seen the conception of extremely accurate, almost unbreakable pressure based switches for some industrial applications.
In conclusion, it can be seen that the need for reliable pressure activated switches is beginning to grow quite quickly, even though, as predicted by Mangi (1992) growth in this industry is still quite slow. As more niches are found for these devices however, especially regarding safety, it is believed that pressure activated switches will begin to be taken seriously as hazard prevention mechanisms.
