Why Use Limit Devices in Temperature Control
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WEST Control Solutions – Your global partner for measurement and control technology Why Use Limit Devices in Temperature Control Applications? Limit Devices – why they are required, how they work and the benefits you can gain by using them

WEST Control Solutions – Your global partner for measurement and control technology Why Use Limit Devices in Temperature Control Applications? Limit devices provide vital protection for temperature controlled process systems, ensuring product quality and the safety of both the workforce and the plant itself. The questions this presentation seeks to answer are: • What are the dangers with temperature control systems? • How does a limit device work? • How do limit devices reduce risk? • What are typical applications and standards for limit devices?

WEST Control Solutions – Your global partner for measurement and control technology What are the dangers with temperature control systems? Temperature control systems can all potentially cause serious safety issues such as fires if they’re not managed correctly. Regulations are often in place to mitigate the risks associated with temperature control systems. The operation of ovens and kilns in the USA is regulated by the NFPA (National Fire Protection Association). NFPA 86, the Standard for Ovens and Furnaces, was drawn up to minimize fire and explosion hazards in ovens and furnaces which...

WEST Control Solutions – Your global partner for measurement and control technology How does a limit device work? Limit devices are typically used when there is a safety or quality requirement to protect a product or appliance from damage caused by excessive temperatures. They are used in process control applications where independent limit switching for over or under temperature is required. Typical working operations include: • A high and a low temperature cut off, so if the pre-set temperature limit is exceeded then the system is shut down Limit Devices can typically be used with a...

WEST Control Solutions – Your global partner for measurement and control technology How do limit devices reduce risk? Limit devices reduce risk by switching systems to failsafe a mode if their limits are exceeded. A signal is sent once the limit temperature has been reached to make the temperature process safe, by forcing a cooling process for example. Importantly, once the failsafe process has begun, it requires manual intervention to restart. This encourages human checking of the conditions before the process can be reset.

WEST Control Solutions – Your global partner for measurement and control technology What are typical applications and standards for limit devices? Limit devices are increasingly becoming specified installations according to national safety regulations. As well as the NFPA 86, US insurer FM Global have included the use of limit devices as standard in their terms of insurance. In Europe the, EN 14597 standard applies to: “electrical or non-electrical temperature control devices which are used to control temperatures within heat generating systems…and to limiting devices which ensure that the...

WEST Control Solutions – Your global partner for measurement and control technology Thanks for your interest. If you have a temperature control application and would like to improve safety then please visit our website to select a limit controller and request a quotation. For all our latest news, follow us on social media