About Sofis

Sofis is a global leader in the field of valve operation. With our products and services we help our customers to improve safety and efficiency of their valve operations.

  • Our various product lines around valve interlocking improve your process safety and ensure first-time-right operation.
  • Our drive systems ease your operation of manual valves, driving efficiency.
  • With our valve monitoring systems you can check manual valve positions or the maintenance status of your ESD’s.

We are found on top of valves but we also think beyond them. We have evolved into specialists who know how to operate valves. We want to further develop the field of valve operation, because there is much room for improvement when it comes to running a plant.

We believe that smart valve operations are key to run a plant as efficiently and safely as possible. An integrated approach is necessary in order to increase performance, create a better working environment and minimize interruptions or shutdowns.

By offering sophisticated integrated solutions, based on a complete range of premium products and excellent support, we enable you to achieve optimal performance. We help you to create ultimate flow.

A merger of Netherlocks and Smith Flow Control

Sofis is a new name in the market, but far from a new player. Sofis is built on decades of market leadership from the two most renowned brands in valve operation: Smith Flow Control and Netherlocks Safety Systems. The merger of these two companies resulted in the global leader in smart valve operation solutions: Sofis.

We are smarter together. With our combined expertise, our united service team and a joint office and partner network we will provide more local support and site service for our installed base and projects as well as extend our reach into new territories.

Over the last three decades we have led and developed the interlock market. We also devised new product segments (e.g. valve monitoring and drive systems) by continuously bringing new ideas to fruition. Now it is time to take the next step and further explore our, and your, potential.

Valve interlocking

Valve interlocks enforce adherence to your valve operating procedures. With mechanical valve interlocks permanently mounted on your valves, you avoid human error during critical valve operations.

Since Sofis combines the knowledge and experience of Smith Flow Control and Netherlocks Safety Systems, you benefit from unprecedented interlocking expertise. We help our customers in their interlock sequence design, development of customized solutions and execution and management of large and complex projects.

Sofis is the developer and manufacturer of the most renowned interlocking brands:

  • Smith interlocks
  • Netherlocks interlocks

Interlock switch lock       Netherlocks 364506

Smith interlocks

The Sofis Smith interlocks are the industry standard for premium valve interlocks since 1985. By introducing the coded card linear key, they laid the foundation of the modern interlocks that are till date considered the premium standard.

Smith interlocks are made of premium materials and are coated by default. Their mechanism and mounting kits are based on over 30 years of experience in the global Oil & Gas and process industries. They are found in nearly every plant and more than often, plant specifications request for “Smith locks”, which tells a lot about the market acceptance of this product.

Netherlocks interlocks

Netherlocks Safety Systems launched their valve interlocks to the market in 1993. The Dutch design of these interlocks is also based on the modern standard of linear key locking. Netherlocks interlocks design further developed throughout the years based on extensive experience with the major oil and chemical companies in The Netherlands. Nowadays, these companies are key users of Netherlocks interlocks in all parts of the world.

Netherlocks interlocks are made of high performance AISI 316 stainless steel and are designed for the most challenging environmental conditions.

Sequence control

With Sofis sequence control solutions you integrate interlocks with your control system. Sequence control products manage the issuance of interlock keys, based on control system inputs. Through this coupling of manual and automated systems you further improve your process control.

We offer panels, cabinets and key exchange units that manage issuance of interlock keys, based on electronic input from field devices like meters, positioners and actuators. They manage that interlocked systems operation can only commence or continued, with authorization of your control system based on any type of process parameter. You thus increase safety and flexibility while simplifying your interlocking procedure. And you receive clear operating guidance from the system to help with operation.

Sofis sequence control systems are applicable for both Smith interlocks and Netherlocks interlocks.

Key management

Our key management product-line consists of a range of interlock key cabinets with additional features. Key management cabinets manage and register the presence and issuance of interlock keys.

With the help of key management cabinets you gain insight in your plant status. The cabinets signal the presence of operating keys to your DCS, which gives information about the status of your interlocked valves and systems.

With our key  management cabinets you also ensure that valves are only operated by authorized personnel and at the right moment. And the cabinets allow you to keep track of key usage and system operations on an individual operator level.

Sofis key management systems are applicable for both Smith interlocks and Netherlocks interlocks.


We have a range of unique valve lockout products to temporarily lock valves during maintenance. During maintenance you prevent valves from being accidentally operated. Use these lockouts for any type of valve.

VPI position indicators

Our VPI position indicators provide reliable, real-time status information from your manual valves to your control system. It is a unique product, specifically designed for multi-turn valves like gate and globe valves. It sends electronic signals when your valve reaches its fully open or closed position and also gives position information in the field with the use of LED indicators.

FAITH partial stroke

With FAITH partial stroke you ensure that your critical MOVs perform upon request. This mechanical PST system facilitates partial stroke test of your critical MOVs during normal operation. The FAITH partial stroke is a bracket and drive bush with testing capabilities. In test mode, FAITH partial stroke mechanically blocks valve movement for a safe test with reliable results.

IML actuator lock

To safely service your actuator during normal operation, the IML actuator lock temporarily locks out your MOV. You can maintain your actuators while they’re online, without the risk of accidental valve movement. Our actuator locks are mounted between your valve and actuator. When in maintenance mode, they block valve movement during actuator maintenance to keep your valve in a secured position.

EasiDrive portable actuator

Frequent operation of heavy manual valves is easier with the EasiDrive. This easy-to-carry pneumatic tool eases manual operation of your hard-to-operate manual valves. Save on your actuator CAPEX by operating large numbers of valves with only one tool. And guarantee safe operation with its bespoke mounting kit with reaction device.

Power Wrench portable actuator

With the Power Wrench you increase valve operating speed. It helps you to significantly reduce time spent on incidental valve operation during downtime and maintenance. You equip any multi-rotation valve with a universal Power Wrench coupling within just minutes. Power Wrench offers you speed and convenience, wherever and whenever you need it.

FlexiDrive remote operator

You operate hard-to-reach manual valves safely and easily with the use of a FlexiDrive. You can operate every manual valve from a safe and convenient location. Mount a valve station to your valve and operate your valve with the operating station up to 30 meters away. Ensure safe operation, save costs for scaffolding and avoid unnecessary actuator CAPEX.

Press Release:




Nitul Sanghvi – India Sales manager
Tel: +91 265 234 11 34
M: +91 98795 59345