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TRAPPED KEY
INTERLOCKS
What is a trapped key
interlock system?
The use of interlock systems is a proven method for predominantly mechanical securing of machines and processes.
The principle of interlock systems is based on the releasing and locking of uniquely coded keys in a predetermined sequence.
TüV certified
Ple according to EN/ISO 13849-1
200.000 unique key codes
Mechanical interlock systems
Our range of interlocks for mechanically securing machines
Key exchange unit
For isolating multiple energy sources or accessing multiple doors
Door interlock
with safety key
For the safe opening of doors and hatches and the prevention of entrapment hazards
Do you need support?
Contact our specialists
The only interlock system that is TüV certified to Ple
mGard is the product group of Fortress interlocks of mechanical key transfer systems (interlocks). mGard is the only interlock system on the market to be TüV certified to PLe (EN ISO 13849-1).
In addition, with more than 40 years of experience, Fortress Interlocks offers an extensive range of interlocks for virtually any machine safety application.
- 200,000 unique keycodes with database management on end user.
- Door lock withstands up to 7500N pulling force.
- Use safety keys (with mandatory key removal) to prevent entrapment.
- Colour coding and laser engravings for identification purposes
- Modular structure for easy modification and expansion of the system
- Available in Mazac (zinc aluminium) or INOX316
Isolate
Isolation key A
Isolate
Isolation key B
Safety Key
Safety key a1
Safety Key
Safety key B1
How does an interlock system work?
Trapped Key Interlocks are an approachable way to safeguard your machinery.
Just use the following checklist.
- Does the machine have a run-down time or should the process not be interrupted (controlled shutdown yes / no)?
- Determine the number of access points to your machine
- Do all access points have to be open at the same time?
- Determine for each access point whether there is a risk of accidental lock-in (safety key yes / no)?
- Select the correct actuator / tongue for each type of access point (hinged door, sliding door or hatch).
- Select the right material for the environment (stainless steel or Mazac).
- Is it allowed for the system to be bypassed with a master key under certain conditions?
mGard key switches
Use our XMR or S safety key switch to isolate the installation. Turning the first key will engage the safety contacts and releases the key(s).
The released keys can be used to safely unlock doors and hatches. Only after all keys have been returned, the first key can be turned once again to restart the machine.
- Suitable for usage in SIL3 (EN/IEC 62061), Category 4 (EN 954-1) and PLe (EN/ISO 13849-1) applications
- 200,000 unique key codes
- Robust INOX 316 casing or Zamac (zinc aluminium alloy)
- Can be used as a coded safety switch in accordance with EN14119
- Modular design for easy addition of doors/hatches
- Flush mounted and surface mounted (IP67) versions available
Flush mounted or surface mounted
All Fortress Interlocks mGard key switches are available as a flush mounted or surface mounted variant.
In addition to IP66 plastic and steel casing, the mGard key switches are also available in entirely INOX 316.
Laser engraving and colour coding
The robust CL locking mechanism is available in 200,000 unique key codings. In addition, the key codes and engravings are stored per end user to prevent issuing of duplicates.
Free of charge colour codings in laser engravings can be used for identification of key and lock.
Padlock lockable
In case multiple persons are to enter the protected area, or if a lockout tagout takes place, make use of dust covers that can be locked by means of padlocks.
Placing a padlock prevents the insertion of the key and thus prevents machine restart.
mGard lockable
key switches
Does your machine have a run-down-time or should the door/hatch not be opened at all times? Then use our SS solenoid controlled safety key switch for a controlled machine stop.
After energizing the solenoid, the keys can be turned and removed and then used again to open access doors or hatches.
- Suitable for usage in SIL3 (EN/IEC 62061), Category 4 (EN 954-1) and PLe (EN/ISO 13849-1) applications
- 200,000 unique key codes
- Robust INOX 316 casing or Zamac (zinc aluminium alloy)
- Can be used as a coded safety switch in accordance with EN14119
- Modular design for easy addition of doors/hatches
- Flush mounted and surface mounted (IP67) versions available
Flush mounted or surface mounted
All Fortress Interlocks mGard key switches are available as a flush mounted or surface mounted variant.
In addition to IP66 plastic and steel casing, the mGard key switches are also available in entirely INOX 316.
Modular
Both lockable and non-lockable key switches from the mGard product group are modularly structured.
The great advantage of this is that an extension module can easily be used for the expansion of the system, for instance if doors or hatches are added.
Request and reset
Add push buttons and/or status LED's toe as an indication, for access request or as a reset.
These function modules are available in flush mounted as well as surface mounted versions.
mGard
bolt locks
Bolt locks are used to lock isolating switches, valves, ball valves or level-operated switches..
By applying a cylindrical bolt, these energy sources can be mechanically locked in the "off" position, after which a key can be taken as a safety key or to be used for the engagement of another energy source or the opening of a door /hatch.
- Robust casing in Zamac (zinc aluminium alloy) or INOX 316
- 200,000 unique key codes
- Different sequences possible
- Modular structure for extension with multiple locking mechanisms
- Well resistant to moist, vibrations and dust
- To be used in EX zones 1, 2, 21 and 22
Detection
The BMR cylindrical bolt lock makes it possible to check the position of the cylindrical lock through an integrated safety switch.
Key sequence
BM cylindrical bolt locks offer the possibility to determine the sequence of the keys yourself. For instance, key free = cylindrical lock applied or reversed functionality.
mGard key exchange unit
Sleutelwisselunits of key exchange boxes worden gebruikt wanneer er met één sleutelschakelaar meerdere deuren dienen te worden geopend of wanneer meerdere energiebronnen dienen te worden geïsoleerd alvorens toegang tot de installatie mag worden gegeven.
Geschikt voor gebruik in SIL3 (EN/IEC 62061), Categorie 4 (EN 954-1) en PLe (EN/ISO 13849-1) applicaties
- 200,000 unique key codes
- Robust INOX 316 casing or Zamac (zinc aluminium alloy)
- Modular design to easy add lock mechanisms
- Determine the key sequence yourself
Modular design
With the XMA expansion module, lock mechanisms can easily be added to existing configurations, for example when adding doors or shutters.
Sequence locking mechanisms
Decide how many keys are trapped and released
When, for instance, initially two energy sources must be isolated before one door may be opened, the sequence is: 2 in = 1 out.
mGard door locks
DM and DMSK door locks are opened with the released access keys from the key switch.
As long as the door is open, the key cannot be removed, as a result of which the machine cannot be restarted.
Door locks are available in Zamac (DM), INOX 316 (DMS) and a fully hygienic INOX 316 variant (DMSK)
- 7.500N tensile force
- Suitable for usage in SIL3 (EN/IEC 62061), Category 4 (EN 954-1) and PLe (EN/ISO 13849-1) applications
- 200,000 unique key codes
- Head is rotatable in 4 steps of 90°
- Can be used as a coded door interlock according to EN14119
- Entirely mechanical (no cables needed)
- Very robust design, resistant to moist, vibrations and dust
- To be used in EX zones 1, 2, 21 and 22
7.500N tensile force
DM and DMSK door locks can resist a tensile force of 7,500N and are also very well resistant to moist, vibrations and dust.
The stainless steel head is rotatable in 4 positions of 90° so that the door lock can be used for all types of doors and hatches.
Different actuators
Choose from 5 different actuators.
Use the DM-H or DM-A handle actuators when large alignment tolerance is required, or for use on sliding doors. The DM-F fixed actuator is the perfect solution for doors or hatches with a small radius.
Exposion proof and 316 stainless steel
DM and DMSK door locks are suitable for usage in almost all Ex zones.
The DMSK door lock is entirely made out of 316 stainless steel and, as such, suitable for hygienic and corrosive environments.
mGard door lock
with safety key
DM2 and DMSK2 door locks offer the option of (mandatory) taking personal security keys to prevent the risk of entrapment.
Only if the door is closed and the safety key has been put back, the access key can be removed in order to restart the installation.
Double door locks are available in Mazac (DM2), 316 stainless steel (DMS2) and a fully hygienic 316 stainless steel variant (DMSK2).
- 7.500N tensile force
- Suitable for usage in SIL3 (EN/IEC 62061), Category 4 (EN 954-1) and PLe (EN/ISO 13849-1) applications
- 200,000 unique key codes
- The head is rotatable in 4 positions of 90°
- Can be used as a coded door interlock according to EN14119
- Entirely mechanical (no cables needed)
- Very robust design, resistant to moist, vibrations and dust
- To be used in EX zones 1, 2, 21 and 22
- Available with different actuators
- Optional: mandatory removal of safety key for extra safety
Prevent entrapment
Safety keys prevent entrapment of employees in protected areas and enclosed spaces.
Take this key along with you to exclude the risk of a machine restart and locking of the door.
Combine wit amGard
Combine the mGard product group of trapped key interlocks using amGard Pro and amGard S40 for even more possibilities.
Because these product groups all make use of the same locking mechanism, combinations can easily be made.
Mandatory key removal
In addition to the standard safety keys, with mGard it is also possible to choose a safety key with mandatory key removal (DMS2E).
Hereby it is only possible to unlock the door when the key actually has been removed.
Sofis interlocks
for valves
Sofis, formerly Smith Flow Control (SFC), valve locks are used to make sure that the operators use the correct sequence when manually locking and unlocking valves.
The valve lock or valve interlock is mounted on every individual valve in the process, to exclude human failure. Valve locks are available for valves with levers (QL lock) or handwheel valves (GL lock).
- Determine the key sequence yourself
- Detect optional key removal
- Fits on every valve through an adapter set
- Entirely mechanical (no cables needed)
- To be used in EX zones 1, 2, 21 and 22
- Version for handwheels (GL) and ball valves (QL)
Adapters for every type of valve
By using an adapter set, Sofis interlocks can be placed on any type of handwheel or ball valve.
The adapter is custom made and measured on site by our technicians to ensure it will fit.
Actuator operated valves
The IML valve lock is used to lock actuator-operated valves during maintenance.
The interlock is placed between the valve and the actuator and can easily be operated with a coded key.
Lock in 2 positions
Determine the sequence of the key removal of your valve locks; release of the key in open or closed position. This will prevent two valves from being open at the same time.
We are
here to help
Contact one of our technical specialists or sales engineers
marco.heijkoop@usp-safety.com
rick.dejonge@usp-safety.com
rob.voordendag@usp-safety.com
robert.vandeven@usp-safety.com
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a meeting
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