Interlocks for Globe Valves

Globe valves are used for regulating the flow inside a pipeline. This could be manual or automated. In order to ensure safe operation of globe valves, Alcatraz Interlocks provides multi-turn locks with both single and double keys in sizes small & large.

Alcatraz integral multi-turn (type ML#) valve interlocks fit on all types of handwheel operated valves, such as gate, globe and all gear operated valves. The interlocks are easy to install, even when the valve is in a live process. They are mounted on multi-turn valves to interlock the locked open and/or locked closed position of the valve. Only if both keys are inserted into the lock portions the valve can be operated. The first key can only be released in the fully open position, the other key can only be released in the fully closed position.

Alcatraz’ Interlocks for globe valves can be used to control valve flow, ensure safe valve operation, pressure safety valve systems and pig trap systems.

Interlocks for Lever Operated Valves

Ball valves and plug valves are being used as a shut off valve that controls the flow of a liquid or gas by means of a rotary ball or plug having a bore. These valves are most commonly manually operated.

In order to ensure safe operation of these valve types, Alcatraz Interlocks provides quarter-turn interlocks, with both single and double keys in three sizes: small, medium and large.

Alcatraz integral quarter-turn (QL#) valve locks fits on all type of lever operated valves/quarter-turn valves such as ball valves, plug valves, 3-way valves, butterfly valves and even instrument valves. They are mounted on 90° rotating valves to interlock the locked open and/or locked closed position of the valve. The key movement is only possible in fully open or closed position thus providing an extra confirmation that the valve is in the exact desired position as compared to other options such as car seals.

Interlocks for Butterfly Valves

Butterfly valves are used where space is limited. Unlike gate valves, butterfly valves can be used for throttling or regulating flow as well as in the fully open and fully closed positions. The pressure loss through a butterfly valve is small in comparison with the gate valve.

In order to ensure safe operation of butterfly valves, Alcatraz Interlocks provides quarter-turn interlocks, with both single and double keys in sizes small, medium and large.

Alcatraz integral quarter-turn (QL#) valve locks fit on all types of lever-operated valves/quarter-turn valves such as ball valves, plug valves, 3-way ball valves, butterfly valves and even instrument valves. They are mounted on 90° rotating valves to interlock the locked open and/or locked closed position of the valve. Only if both keys are inserted in the lock portions the valve can be operated. The first key can only be released in the fully open position, the other key can only be released in the fully closed position.

Interlocks for Gear Operated Valve

In order to ensure safe operation of gear operated valves, Alcatraz Interlocks provides multi-turn interlocks, with both single and double keys in a standardised size.

Our type ML# interlocks suit all types of gears which are handwheel operated. Available in single or double key styles, locking the valve in either the open or closed position. If the double is specified, the valve can be locked in both the open and closed positions. Forming part of a complete range of our process interlock safety systems. All of our valve interlocks have a tailor made mounting kit that is non-intrusive to the gear or valve. When used with other Alcatraz interlocks, operators are constrained to follow the correct mechanical sequence of operation of all valves within the interlock sequence.

The Alcatraz interlock incorporates a counting mechanism, which is commissioned as standard at the factory but will require recommissioning after installation to trap and release keys at the desired gear position.

Door locks for machine guarding

A Door Lock is an Interlock device designed to lock a gate, guard or any other type of access door.

The #DL Interlock is available in two versions; single key and double key. Exchange key condition and double condition are available to accommodate a variety of interlock sequence requirements.

Standard latch or chain latch versions are also available. A standard latch is best for doors or gates which have good hinge alignment while chain latches are best for doors that have poor alignment.

Our Bolt/Door Locks have now been developed to use a single unified body allowing it to be assembled into the required application ranging from Single Key Bolt Lock, Single Key Door Lock, Double Key Bolt Lock and Double Key Door Lock with more applications upcoming.

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Power Isolation is the first stage of any interlock sequence. There are additional factors to be taken into account regarding the equipment. For example:

• Inertia: Does the machine have rotating parts that continue to spin under inertia, even after power has been switched off.
• Moving parts: Does the machine have moving parts that continue to move after isolation. For example, heavy equipment may move under its own weight.
• Presence of pressure: Sealed, contained systems can hold pressure which can still release in an uncontrolled manner.
• Extremes of heat and cold: Stabilizing heat and cold to ambient temperature can be essential to ensure to avoid burn injury.

All of these issues can be controlled, depending on your choice of power isolation interlock. Here are some examples of power isolation interlock.

Standard On/Off Switch Interlock This device uses a choice of multi-pole isolating switch, commonly 2 Normally Open / 2 Normally Closed contacts 2NO/2NC starts at 20Amp current isolation and rises to 200 Amps and above. The switch interlock can be supplied in its own enclosure (GRP or Stainless Steel), or plain for panel mounting in an existing control panel.
Solenoid Controlled Switch Interlock This interlock device can also comprise an on/off switch as above, but it has the additional feature of a solenoid which traps and releases the operating key. The solenoid can be controlled by a temperature sensor (hot or cold), a pressure sensor or a movement sensor. When the control system detects specified temperature, pressure, or absence of movement, an LED on the interlock housing illuminates to indicate ‘Safe Conditions’. The operator can now press the button which retracts the solenoid and releases the interlock key.
Timer Delay Interlock Some machinery will take a finite amount of time to come to a standstill, after power has been switched off. In these instances, a Timer Delay Interlock can be used. Turning off the power causes the timer to commence counting. After a pre-defined set amount of time, the interlock releases the trapped key.

Valtorx recommends a thorough risk assessment to determine the risks and identify the most suitable type of Power Isolation Interlock to achieve the required level of safety and control.

Bolt Interlocks

Alcatraz Interlocks provides both single and multiple keyed bolt locks. These bolt locks are used for machine guarding. Our bolt locks are often used on, but not limited to, rotary switches and electrical switchgear. Our Bolt/Door Locks have now been developed to use a single unified body allowing it to be assembled into the required application ranging from Single Key Bolt Lock, Single Key Door Lock, Double Key Bolt Lock and Double Key Door Lock with more possibilities upcoming.

Interlock for Motor Operated Valve (MOV)

Alcatraz MOV Interlocking applications, are designed to suit Electrical, Pneumatic & Hydraulic controlled actuators. MOV interlocks mechanically block various parts of the actuator, such as the local power supply, valve position indicator plate located on top of the gear-unit, and the manual override. Next to our standard mechanical items we can also fit electronic components for digital feedback. Alcatraz Interlocks has designs for different systems. By the exchange of mechanical coded keys between the different components of the actuator, operation of the actuator can incorporated into mechanical interlocked systems.

The interlock on top of the indicator of the gear-unit has three different keys which exchange based on the position of the valve, two different keys for the open and closed position of the valve and one switch key for operating the MOV. On the Manual Override, an interlock is fitted configured to accept the only switch key. The actuator switch is fitted with an interlock which is also configured to accept the switch.

The initial valve position key is inserted into the indicator interlock allowing to release the switch key, this blocks the initiating position key in place and unlocks the indicator interlock. The switch is inserted into either the Actuator Selector Switch or the Manual Override, during operation the switch is trapped.

When the valve is operated to the alternate position the switch key is removed and MOV valve operation is disabled. The switch key is returned to the Gear-unit indicator interlock and inserted into the alternate valve position part of the indicator interlock. The key for the MOV valve alternate position can now be removed, locking the MOV in the alternate valve position and also preventing removal of the switch key. Which during operation of the valve is used to unlock either the actuator switch or the manual override.

All locking systems are built to our standard key coded mechanism.

Solutions for motor operated valve systems:

• Suitable for linear and rotating actuators.
• Suitable for electric, pneumatic and hydraulic actuators.
• Mechanically locks the power switch, position indicator and manual override.
• Integrates MOV’s into an interlocking sequence of manually operated valves.
• 2 sizes: 4-24 inch & >24 inch

Key Exchange Box

A key exchange box (KEB) is used when any number of keys need to release any other numbers of keys. For example, when a single key from a switch needs to release 5 keys to go to several hatches the key exchange box makes this exchange: the key from the switch is inserted, only after which any number of keys can be removed to operate other interlocks. Only when all keys have been returned does this unit allow removal of the initiating key.

These key exchange boxes are purely mechanical, however they can be designed to house any kind of electro-mechanical setup including limit switch or linear solenoid magnets.

The key exchange box comes in various sizes based on your exact needs.

Quick Opening and Closure Locks

The Alcatraz closure door lock is designed to fit on all makes and models of quick opening closures, as found on pig launcher and receiver doors.

The quick opening closure lock prevents the bleed plug from being removed, this means it prevents the closure door from being opened. Only the insertion of a dedicated key releases access to the bleed bolt, so it can be removed. This key is only released after the door is closed and the bleed plug is back in its place.

Interlocking of the door is an essential element of safe loading and unloading procedures associated with pig launchers and receivers.

During the pig launching and receiving procedure, the operating written procedures must be followed carefully by the operators. If the vessel is not drained and vented, or when the isolation valves are not fully closed before opening the closure door, extremely dangerous situations can transpire. The Alcatraz Interlocks closure lock (CL), as a part of an interlocking sequence, prevents these hazardous situations.

By guaranteeing and safeguarding that the isolation valves are closed and the vessel is vented and drained before the closure door can be unlocked and opened.