Beacons: What is the meaning of each colour lens?
Author : Hardy Hopkinson, Ex-Tech Signalling
07 June 2024
Beacons certified for explosive atmospheres in industries such as oil & gas, petrochemical, pharmaceutical, marine, and offshore are a vital way to quickly and effectively communicate current conditions on a process or in a plant.
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IEC 60073 establishes general rules for assigning particular meanings to certain visual, acoustic and tactile indications. This is in order to increase the safety of persons, property and/or the environment through the safe monitoring and control of the equipment or process, facilitate the proper monitoring, control and maintenance of the equipment or process, and to facilitate the rapid recognition of control conditions and actuator positions. This article looks at the meaning behind a range of different coloured beacons.
Red lens beacons
Red is traditionally associated with danger or an emergency. In Audible Visible Signalling Devices (AVS), such as beacons, this is no different with red representing an emergency, a dangerous or hazardous condition, or a situation which requires immediate action. Signal lights with a red beacon light are also suitable for signalling system failures, values that lie outside their safe limits (e.g. temperature or pressure) or if there is danger.
Absolutely, a red beacon light is a critical situation that would require swift action in any application and is hazard-implying. The highest warning level is indicated by a red beacon light. When it lights up, it stands for the highest level of urgency and not to be used in general IEC 600073 guidelines for “a general warning”. For example, in a manufacturing facility where pressure or temperature has increased beyond the safe range, an immediate shutdown is required due to the action of the protective devices (equipment failure). Exceptions to this rule are two-colour or multi-colour signal systems with only one red and one green warning light.
Yellow lens beacons
These colours, renowned for their intense brightness, are employed to draw attention to specific situations. Yellow and amber beacon lights signal an impending critical state that necessitates human monitoring or intervention. Devices featuring such lights are adept at indicating overloads or surpassing standard values, provided the duration remains within permissible limits. Required actions aim to forestall abnormal conditions and avert ensuing consequences. Yellow or amber lights are apt for cautioning against moderate dangers, serving as precautions and warnings. For example, in a manufacturing facility where pressure or temperature has extended above the normal operating range however has not quite reached the unsafe range, but action within a line is imminently or currently taking place to return the operation of the facility to a safe range of conditions.
An amber beacon light is critical in any plant operation to ensure the safety of personnel. Where toxic and/or combustible gases, dust or liquids may be released generally through a form of a vent into the atmosphere (released by a pressure relief device such as a safety or pressure relief valve).
Green lens beacons
The green colour simply denotes a safe normal state of operation or environment, requiring no immediate action. It's essential to recognise green as a safety colour rather than as a warning colour. Safety guidelines, which already indicate potential hazards, are more appropriately conveyed through blue signals.
Commonly, machines equipped with green beacon lights signal readiness for operation or seamless functioning without any glitches. For example, a green beacon light in a manufacturing facility could signify pressure or temperature in a normal range and no further action is required other than seamless operation of the facility. Many plants use a green signalling beacon to inform other personnel simply that the plant is in operation and not the earlier information regarding what the conditions of the plant are. However, the latter is assumed otherwise operation would be put to a hold to ensure safe operation of the equipment and ultimate safety of all personnel within the facility.
Blue lens beacons
Normally linked to the emergency services, operators should refrain from using blue lights on roads or in areas of public access. Of course, different nations operate their emergency services with different colours. However, in the UK and Europe certainly, blue is connoted to be the colour of emergency services. Many plants or manufacturers of signalling would suggest that blue is a common alternative to red signalling. However, blue beacons can be used to signify any condition necessitating a specific action by the operator, distinct from the states represented by red, yellow, orange, and green colours. Blue can be assigned various meanings beyond these.
This is best explained using an example to distinguish the true difference. For example, emergency evacuation on board a ship, a blue light could signal to an operator to abandon the ship. In manufacturing settings, a blue LED beacon often signifies a distinction, such as prompting a conditioned response to shut down safety-critical processes like switch off the line and evacuate the premises.
Hardy Hopkinson, Ex-Tech Signalling
Clear/white lens beacons
An opaque/clear/white beacon can carry ambiguity. It is best explained by what it should not be used for. Many operators replace their clear domes on their push buttons with stop or off functions. While clear beacon lights have high light transmission without consuming light, they are unequivocally unsuitable for drawing attention to warn of danger despite their brightness. As discussed, there are standards which must be met, and each colour has its own tailored usages.
In a nutshell, a clear beacon light carries no distinct significance. A client would use clear beacons depending on the application and when there's uncertainty regarding the use of red, yellow, green, or blue lights. Whether employee supervision or intervention is needed for the illumination of the clear dome must be evaluated case by case.
Purple lens beacons
Purple plays a prolific role for oil and gas clients, especially in the UAE and USA as an alternative to red. When a purple beacon light in the purple signal colour illuminates, individuals should promptly evacuate the area or trained personnel should take immediate necessary actions.
About the author:
Hardy Hopkinson is a Business development Engineer at Pyropress Ltd and Ex-Tech Signalling. Part of Pioneer Safety Group, these brands provide safety solutions for businesses operating in hazardous or harsh environments. The Pioneer Safety Group comprises Pyroban, EXSolutions, Pyropress, Euro Access, Ex-tech Signalling, Ex-tech Solution and Petrel.
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