Enforce and guarantee a pre-defined valve operating sequence and eliminate human error.
Lead your operators safely through strict work procedures, by only allowing the right valves to be opened or closed in the correct sequence.
Eliminate human error
Netherlocks interlocks eliminate human error by only allowing the right valves to be opened or closed in the correct sequence, leading operators safely through strict work procedures. You can operate them by means of a linear key and guide the operator through a predefined sequence with unique keys for each step. Netherlocks interlocks are used as an industry standard by renowned companies like Total, BP, ADCO and Shell to create a safer working environment.
Discover the basics of Netherlocks interlocks
Use Netherlocks interlocks for valve operations where safe and ‘right-first-time’ valve operation is required, such as pressure relief valves (PSV), pig launching and receiving, inert gas systems, pump start up, flare lines, boiler blow-down, ‘2 out of 3‘ and decoking.
Mechanical valve interlock types
NDL valve interlock
Mount the NDL valve interlock to any type of 90 degree valve, such as ball valves, butterfly valves and plug valves. It only releases a key in fully open or fully closed position. It replaces the original valve lever with a new, stainless steel, sliding lever.
MRL valve interlock
Mount the MRL valve interlock to any type of hand wheel or gear operated valve. It has a mechanical counter that registers open and closed position of the valve. The lock releases keys only in fully open or fully closed position. And it replaces the original valve hand wheel.
With the Closure lock you interlock the closure door of a pigging vessel. The lock prevents the bleedbolt from being removed and thus the closure door from being opened. The bleedbolt can only be removed after you insert a dedicated key. The lock only releases this key after you have closed the door and returned the bleedbolt.
Actuator locking system
The ALS (Actuator Locking System) is a mechanical interlocking device for motor operated valves. It locks and regulates operation of the local controls and manual override of the actuator. With the ALS you incorporate local actuator controls into a manual valve operating sequence.
Actuator switch lock panel
The ASLP (Actuator Switch Lock Panel) is an electronic interlocking device for motor operated valves. It locks and regulates local electronic operation of the actuator. With the ASLP you incorporate electronic actuator operation into a manual valve operating sequence.
Electrical switch lock
With the Electrical switch lock you control the operation of electrical switches. With an Electrical switch lock you include the operation of electrical devices into valve interlock operations. You could for instance prevent starting up a pump unless the suction valve is opened.
75% of the accidents in the process industry happen during startups, shutdowns and maintenance. In 50% of these accidents, root cause is incorrect operation of manual isolation valves. There are many applications where Netherlocks interlocks are an added value by protecting people, the environment or company assets.
Safeguarding complex valve operations
Valve interlocks are frequently used to secure linear valve operating sequences (open valve A, B and C and close in reversed order: C, B, A). Sometimes you must deviate from this linear procedure and repeat steps or return to previous steps, not in reversed order. Sequence control products guarantee these non-linear steps in a valve operating sequence.
With our new generation of intelligent interlock key management systems, you have various possibilities at your fingertips to optimise interlock and process performance. You can now utilise a vast array of additional data and intelligence, whilst ensuring safety of your operators and plant are held paramount.
Renowned companies use Netherlocks interlocks as an industry standard to create a safer working environment.
How can we help you?
With 30+ years of experience we can help you setting up safe valve operation sequences. Let us share the lessons we’ve learned with you by participating in HAZOP studies, sharing application knowledge and customized valve interlock solutions.