‘With a track record, which expands over three decades, our customers return to us, time after time.’ Using Smith Flow Control’s (SFC) interlock solutions, we help you reduce the scope for operator error and ensure safe and continuous operation of your plant. About process interlocking Although accidents in process industries are fairly infrequent, when they do happen, they tend to be serious in scale and nature. Operator mistakes and failure to follow procedures or bypassing steps, carry great risks. The start-up, shut-down and shift hand-overs are all examples of where one small slip in due...

Guiding you through safe work procedures step by step Human error is removed as when using our valve interlocks, your operators are compelled to follow a safe sequence of valve operations There are no short-cuts. Multiple benefits from using our interlocks • You create a safer working environment for your team of operators and those around them. • You promote adherence to safe working procedures and reduce downtime. • You protect the environment through minimising risk. • You reduce potential costs by preventing product loss and reputational ris

QL valve interlocks QL valve interlocks are designed to suit all types of lever operated and quarter-turn valves, including ball, butterfly, and plug valves. You can mount them without any modification to your host valve. Anti-tamper screw Lever Coded lock body Lock adaptor Anti-overide mechanism Locking gear cam Open key

GL valve interlocks GL valve interlocks are designed to suit all types of handwheel operated valves, including Gate, Globe and Gear-operated valves. You can mount them without any modification to your host valve. Coded lock body Lock adaptor Locking arm Counting mechanism Code bars

Access a pressure vessel is a potentially hazardous exercise. Opening a vessel door when there is residual pressure, liquids or gases in your pipelines can cause you serious harm. Examples of potential hazards include pig traps, slug catchers and filter housings. With interlocks you ensure total isolation, venting and draining before your operators can open your vessel door. Using our DL interlock, you can lock closed your vessel door. You will only ever be able to open it, when it is proven safe to do so. As an example, the operating key is held in a control room or retained (trapped) in another...

Actuated (motorised) valves Where you have both power operated and manually operated valves, you can integrate them using interlocks. Typical examples of this include pig launcher/ receiver systems, scraper traps and sand filter systems. Using our MOV interlocks, you can fully integrate your actuators into valve interlock operating procedures and sequences. Integrating manual valve operation into power actuated valves Using our interlocking solution, you can incorporate your MOVs into an interlocking sequence of manually operated valves. You can lock and regulate the operation of components of...

Key cabinets With all valve interlocks, we recommend an effective storage system for your keys. This will help you to prevent unauthorised and inadvertent use of interlocked valves and other important process equipment. Simply by looking at the keys in your cabinet, you gain an overview of the status of your interlocked process systems. A cabinet with all its keys stored, indicates normal operation. Work is in progress when a key is missing from the cabinet. Giving you more from your valve interlock installations Our key storage cabinets provide an additional layer of control over your operators...

ATL (Anti tamper lock) You may require a simple to use locking device to prevent accidental or unauthorised operation. The ATL has been developed to fit directly on to your valves in place of the normal handwheel or operating lever, with minimal machining. This can be easily done at site. Only a designated key allows operation of your valves. Depending on your requirements, the valve can be operated to any position. Once the key has been removed, the unit freewheels and prevents further valve operation. Expanded chainlock The expanded chainlock is the first of two security solutions used for commissioning...

IML intermediate lock With the IML intermediate lock fitted, you can mechanically control any ISO pattern actuator. During maintenance, the command system managing your valves may need to be suspended. Your valves must be set to their fail-safe position and disabled both remotely and locally, so that work can proceed safely. Our IML uses an interlock key to lock your actuator in the desired open or closed position to prevent the valve from turning. ComKey (Commissioning key) Dust plug To commission a system, you will need to operate the valves and their keys as you would under normal conditions....

SCU (Sequence control unit) The SCU is designed to enable you to complete complex variations in your operating sequences. An example of this is on launcher/receiver systems. In normal conditions, all interlock keys in the unit are trapped. It is only when you insert an initiating key and turn the knob (at top of unit), the next process key is released. You can see step by step, which key to remove using the visual indicator. This eliminates any potential for error brought about through bypassing critical process steps. Explosion proof interlock switch The Atex certified switch is used when you...

Pressure relief valves During maintenance of your live safety relief systems, you will need to maintain an open path to relief at all times. Using our interlocks, you will eliminate any pressure build up in your pipelines. PSV interlocking Most pipeline installations will include a spare relief capacity, which enables you to complete your maintenance procedures, whilst continuous production takes place. This eliminates the need to isolate and shut down the whole process, which is a costly and time consuming process. However, when working a live plant, you will want to ensure that only one valve...