The top five ways trapped key interlocks protect workers in the food industry

Trapped key interlocks provide fast, safe and reliable access to machinery, prevent shortcuts and enforce procedures. This is achieved through the transfer of keys as the process is stopped or started. The repetitive wash-down procedures common to the food industry can affect the reliability of electrical safety devices, but the rugged, mechanical nature of trapped key systems makes them particularly suited to food processing applications. Here are the five most popular areas in which mechanical interlocks safeguard workers in the food industry.

1) Palletisers, blenders and mixers

These machines present the same risk – that personnel can be exposed to danger without being immediately visible to others – but for different reasons. In the case of palletisers, the large size of the segregated area, the equipment within it and the full pallet itself make it easy for an operator standing outside the machine guarding to miss a colleague’s presence inside. Blenders and mixers, on the other hand, present an impenetrable metal wall at ground-level to external workers.

Electronic methods of detection are sometimes unable to ascertain if individuals remain within a hazardous area. But trapped key interlocks, through the use of a personnel key, and lockout / tagout procedures can ensure that all operators and engineers are safe prior to the machine running. The operator retains the personnel key the whole time they are in the protected area, putting them in control of the machine start-up. Until this key is returned to its original position, there is no way to restart the machine.

2) Clean-in-place

The nature of the chemicals used in clean-in-place operations means that any product contamination is extremely hazardous to human health. It is therefore imperative that the correct procedure is followed and completed prior to food production starting. Trapped key interlocks force workers to follow a strict process, without them deliberately skipping or inadvertently missing steps.

3) Product filtration valves

Maintaining and replacing filters in food processing pipework while product flow is present carries two risks. First, removing filters can lead to loss of product and high clean-up costs. Second, operators can be exposed to high-pressure and / or high-temperature product. Interlocking product flow and access to filters ensures that access can only be gained when product flow has ceased i.e. when the valve is closed.

4) Dosing

Ensuring the correct dosage of ingredients or additives is administered at the right time can prevent product being spoiled or wrongly formulated, and money being lost. Companies that interlock dosing valves maintain product consistency. Ingredients and additives can only be introduced in the correct order and individual steps cannot be missed or ignored.

5) Ovens and chillers

The risk when maintaining ovens and chillers is that the temperature may not have returned to a safe enough level to allow prolonged exposure by maintenance and operation teams. Having a robust method to guarantee enough time has elapsed before access can be granted means that personnel remain safe while in the danger zone. The access key to the hazardous area is only released once sufficient time has passed to allow the temperature to return to a safe level. The provision of a personnel key that is kept by workers while they are exposed to danger inside the equipment means that they remain in control of the process.

By: David Hughes, Sales Director, Castell Safety International Ltd.

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Castell hosts 2013 channel partner forum

Event helps ensure customers worldwide get latest technical advice

As part of its global sales growth strategy, Castell Safety International recently hosted a forum for its network of international distribution, or channel, partners.

Castell hosts its 2013 Channel Partner Forum

The event saw channel partners receive training in the principles of trapped key interlocking, undertake a manufacturing facility tour and attend presentations focused on Castell’s new product development, vertical market strategy and emerging applications.

Castell’s channel partners help ensure that customers receive expert technical advice, market- and application-specific knowledge, customs brokerage and timely delivery in a large number of countries around the world. The company’s network of partners spans over 20 countries on four continents and includes qualified technical sales engineers who speak more than a dozen languages in total.

Castell sales director David Hughes added: “This event has been a great opportunity to educate our channel partners on our vertical market strategy and help them become experts in our key markets of energy, industrial, manufacturing and transport.”

Channel partners gave presentations on their own markets and Castell success stories, which encouraged discussions on new opportunities across the distribution network. Perry De Brujn, of TSA Safety Group, the exclusive distributor for Castell in the Netherlands and Belgium, commented: “The channel partner presentations greatly enhanced my awareness of the huge range of applications which can be safeguarded using Castell products.”

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Safety interlocking manufacturer appoints new distributor in West Africa

Wined Resources will distribute full Castell Safety International product range

British safety interlocking manufacturer Castell Safety International has agreed a new distribution partnership with Wined Resources, a prominent specialist distributor of safety equipment in Nigeria. The new partnership marks the first time Castell products have been made available through a distributor in West Africa.

A Nigerian company, Wined Resources is based in Warri, a hub of West Africa’s oil and gas industry, and has affiliations with multinational companies. Wined Resources will deliver a full range of distributor services including on-site sales visits, order processing, customs clearance and delivery, and after-sales support.

Castell sales director David Hughes commented: “Nigeria is a growing market for Castell and we are proud to partner with Wined Resources, an organisation with over 20 years’ experience serving the Nigerian business community, and with deep knowledge and expertise in several key industries. Their skilled technical sales team will be able to quickly help customers wanting to buy our products.”

Edwin O. Ezeocha, Wined Resources managing director, added: “Castell’s safety products are well known for their high quality and reliability, and will be an excellent complement to our existing safety product range. We see the potential for a vast range of safety applications across numerous industries in Nigeria.”

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Castell launches new spring-loaded interlock

KSP more efficient than traditional bolt interlocks

Castell has launched a new spring-loaded lock, the KSP, to increase efficiency in traditional bolt interlock applications.

Spring-loaded bolt interlock

The KSP is a spring-loaded version of the Castell K lock, and uses an internal spring to automatically extend the lock’s bolt to its fullest extent when circumstances permit. The key-operated mechanical interlock is suitable for the safe locking of simple actuating mechanisms.

The KSP is generally used at the start of a process and traps a key while equipment is running. When the equipment is switched to a safe state and the aperture in the actuating mechanism is aligned, the spring-loaded bolt automatically extends and is locked in position. This represents an advantage over existing bolt locks as the operation happens immediately and without the need for human intervention.

Once the equipment is in the safe state, the key is released and can be used to gain access or start a separate process. The key must be inserted and turned, retracting the bolt, to allow the actuating lever to be moved again.

Paul Marks, Castell’s technical director, said: “We were already using a spring-loaded lock within our product range and realised that the same device could deliver significant benefits elsewhere for our customers. We view the KSP as an important addition to our existing K bolt interlock range.”

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How trapped key interlocks can ensure the long-term safety of electrostatic precipitators

The hazards of electrostatic precipitators in power generation are well known. High-voltage current, confined spaces and the respiratory risk of fly ash all put workers in potential danger. These issues are compounded by infrequent access and harsh environmental conditions.

This is why selecting a trapped key safety system that provides protection for many years is an important factor in safeguarding power station workers.

Factors to consider when choosing a system include:

•    the product’s ability to withstand hot and cold climates
•    outdoor use
•    the impact of fly ash

This means the type of key (heavy- or light-duty), the material (brass or stainless steel) and the location of the interlocks are crucial to determining long-term usability.

This is only part of the story, though. To perform reliably over many years, interlocking systems need to be maintained and should be serviced as part of a shutdown regime. Simple preventative maintenance steps, such as using graphite powder rather than grease, have a huge impact on longevity.

Regular functionality testing of locks can also prolong a trapped key safety system’s life. This ensures the system is fully operational, saving time and money during a planned or unplanned outage. If locks are only used during an outage and they fail, it can take time to repair or replace them.

Should a failed lock prevent a power station from being brought back online, the financial penalties incurred could be severe. For this reason, it is best practice to regularly check and maintain locks between outages.

With the right maintenance plan, system selection and material choice, a trapped key interlocking system can provide 30-40 years’ service on an electrostatic precipitator, in even the harshest locations.

By: David Hughes, Sales Director, Castell Safety International Ltd.

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NSK improves loading bay safety at Netherlands warehouse

Castell’s Salvo™ also protecting staff at UK facility

NSK, one of the world’s leading manufacturers of industrial and automotive components, has chosen Castell’s drive-away prevention system Salvo™ to protect staff at its warehouse in Tilburg, Netherlands.

NSK warehouse, Netherlands, Salvo, loading bay safety, Castell

NSK’s huge facility distributes more than 4,000 pallets a month across the whole of Europe and North Africa. Customers include Ford, Volkswagen, Siemens and Bosch.

Salvo™ has been installed on 12 loading bays, while NSK has also bought four Salvo™ Club steering wheel locks to safeguard deliveries made by rigid vehicles. There have been no reported health and safety incidents since Salvo™ was commissioned at the Tilburg site.

Having reversed their vehicle onto the relevant loading bay, drivers install the Salvo™ SGL lock on the exposed emergency airline coupling, releasing a trapped key. This key is then inserted and turned in the Salvo™ Control Panel (SCP+) on the outside of the bay. An amber beacon illuminates on the inside to indicate that the loading bay is now safe and ready to use. The loader opens the door, trapping the key in the SCP+ outside. While the door remains raised and the key trapped in the control panel, the trailer cannot be moved.

NSK has also installed Salvo™ at its distribution centre in Newark, UK.

The Health & Safety Executive booklet ‘Warehousing and storage: A guide to health and safety’ recommends interlocks as a safe system of work to combat drive-aways. Salvo™ also features as an example of a safe system of work in the Freight Transport Association’s ‘Loading dock safety guide’, produced in conjunction with the Institution of Occupational Safety & Health.

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Castell’s new range of padlocks now even safer

Improved differ code delivers higher level of complexity

Castell has launched an enhanced version of its Iso-Lok padlock range. The new range features a more complex differ code system, increasing the overall safety level offered to customers.


Castell’s tracking system already ensures that each padlock supplied to a site is unique. This removes the issue of keys fitting multiple padlocks and therefore reduces risk in lockout / tagout procedures. The company’s enhanced range of padlocks now takes the separation of differ codes one stage further.

“The quality of the Iso-Lok range is very important to our client base,” said David Hughes, Castell’s sales director. “By increasing the integrity of our padlocks we have effectively increased the safety of the Iso-Lok range.

This product improvement – coupled with our ability to track differ codes, paint and engrave padlocks – delivers substantial value to our customers.”

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Five ways trapped key interlocks can protect people in the waste industry

Safety in the waste and recycling industry is a key focus of the HSE.

The recent Waste Industry Safety and Health (WISH) Forum blueprint (PDF), produced with the HSE, highlights the sector’s potential dangers and sets out a road map to reduce risk and improve safety knowledge in the industry.

Here are five reasons why trapped key interlocks can improve safety in the waste and recycling sector:

1.    They’re foolproof and ensure equipment can only be used in a safe way.

2.    They’re mainly mechanical and easy to install and retrofit.

3.    They’re hard-wearing and can withstand harsh environments.

4.    They can be installed on the full range of equipment found at a waste and recycling site.

5.    It’s not always easy to spot when someone is in a dangerous area before a machine starts. ‘Personnel keys’ remove this risk: a machine can’t be started until the keys are returned by operatives from the hazardous area.

By: David Hughes, Sales Director, Castell Safety International Ltd.

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Safety interlocking guide improves efficiency in waste and recycling industries

Castell’s new brochure informed by 90 years’ experience of high-risk sector

Castell has produced a new interlocking guide for the waste and recycling sector. The guide suggests ways in which customers in those industries can safely interlock their particular application, ensuring that personnel are protected while operations remain efficient.


The application guide can be downloaded from:

In the waste and recycling industries, safety interlocks are typically used to safeguard sorters, shredders, compactors and bailers. Following growth in waste-to-energy projects, Castell has increasingly been asked to ensure safe access to emission control systems, protecting personnel from high-voltage equipment.

Between 2004/5 and 2011/12, 97 workers were fatally injured in waste and recycling activities, making it one of Britain’s deadliest industries.

Through robust mechanical design, Castell’s products are guaranteed to perform over extended periods of time, particularly in harsh conditions and aggressive environments.

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New switchgear interlocking application guide facilitates selection

Switchgear safety specialist Castell has released a new application guide for switchgear interlocking that makes it easier to understand and choose interlocks for a wide variety of customer applications.


The guide covers the following industrial applications: earthing systems; high-, medium- and low-voltage hazards; switching incomers onto common supply busbars; switching UPS systems and generators on to common supply busbars; and controlling the supply from multiple incomers.

Castell has been safeguarding electrical networks for over 90 years. The ability to work across high-, medium- and low-voltage applications means that a single Castell system can be used to provide personnel safety and ensure equipment is operated in the correct way.

Working closely with key switchgear manufacturers, Castell assembles interlocks designed specifically for use on the leading OEM’s breakers, isolators, disconnectors and earth mechanisms. The new application guide shows how Castell’s interlocks can be used in conjunction with the equipment of leading manufacturers.

The new application guide can be downloaded from the Castell website

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