Idem Safety Introduces Guard Locking Switches for Harsh Environments

Idem Safety has developed the HLZ locking safety switch, capable of withstanding 10 kN of force before failure, meaning devices meant to stay closed will stay closed until the proper conditions are met. This type of engineering control is significantly safer than relying on standard operating procedures (SOPs), training, or policies alone.
 

The Hierarchy of Controls. Image courtesy of Wikipedia

The Role of Locking Safety Switches

Safety engineers often refer to the Hierarchy of Controls, which ranges from the most effective control mechanisms to the least. At the top is elimination; eliminating the hazard completely is the most effective method. At the bottom is personal protective equipment (PPE), which is a last resort in a safety plan.

Locking safety switches, such as Idem’s new HLZ heavy-duty guard locking safety switch, are a type of engineering control. Once installed, they are passive; the technicians do not need to do anything to activate them. They remain latched until a specific set of conditions is met, preventing exposure to hazardous conditions. As an engineering control, safety switches are much more effective than an administrative control, such as an SOP or policy.

A good safety switch will remain latched, even if someone tries to defeat the safety system by prying, banging, or forcing the system apart. Depending on the system, the latch may also need a “fail open” or “fail closed” mechanism for power outages.

Consider a high-speed centrifuge, commonly used in the pharmaceutical industry. Perhaps a technician started the spinning sequence prematurely. The SOP says not to open the centrifuge, but the technician may try to open it anyhow in an attempt to save the batch of medicine. If the SOP is all that stands between the technician and the high-speed centrifuge, injury is likely. Instead, the Idem HLZ safety switch will simply not allow the technician to open the centrifuge.

Idem’s HLZ heavy-duty guard locking safety switch features up to a 10 kN holding force. Image courtesy of Idem Safety

HLZ Heavy-Duty Guard Locking Safety Switch

The HLZ series locking safety switches can withstand up to 10 kN of force before failure. Once it is locked, it will remain locked until the proper conditions are met. This makes it suitable for heavy doors, large lids, and enhanced machine guards where a lighter lock simply will not hold.

Should it be used on heavy doors, it can be supplied with an optional backside release. For example, if it is used on an industrial oven, and a worker gets trapped inside the oven, they can pull the release and escape.

The switch itself can be connected with M20 or M12 connectors. It has OSSD safety outputs rated to Category 4, Performance Level e, and SIL 3, indicating a very low failure rate, even with a system fault present. It continuously monitors for fault conditions as well.

Another key feature of the HLZ is its durability in harsh and challenging environments. The HLZ is rated to IP69K, meaning it is dust-tight and suitable for use in steam and high-pressure water environments.

Idem’s HLZ includes an optional rear escape release. Image courtesy of Idem Safety

Safety in Harsh Environments

Numerous applications require heavy holding force. What makes the HLZ special is the IP69K rating. Idem Safety designed this lock specifically for harsh applications, including those in the food and beverage and pharmaceutical industries. Given the high IP rating, this lock is suitable for washdown applications and clean-in-place and steam-in-place cleaning and sanitization work, which has become standard for these industries.