Solenoid Valves used in Safety Instrumented Systems


Redundant function is most popular in ESD (Emergency shut Down) type application.

Usually these products are part of the shut down loops and connected to an independent shut down control system which may be Double or Triple redundant.

Depending on the application demand, three types of redundant systems are in use:

1oo2 type voting system for high safety loops where in tripping of any of the switching circuit will trip the application.

This is typically required for critical circuits where in failure to shut down safely can have catastrophic consequences.

2oo2 type voting System for high demand loops requiring high uptime avoiding spurious trips due to equipment malfunctions.

These types of systems are called for in mission critical application where in equipment failure can result in heavy losses for plant.

2oo3 type voting system combining high demand and safety in system using

Triple Redundant control systems to ensure safety and high uptime.

These types of system are installed on most critical operations in highly hazardous process Industries.


ROTEX is in a position to offer solutions for all of the above conditions using a Redundancy in Operator type principle which essentially combines independent Valve operating components arranged in redundant configurations. This concept is most superior to the Redundancy in Solenoid since it makes the complete valve component redundant to each other reducing the probability of failure of these valves. The system, essentially a single block solution, eliminates all interconnecting point leakage thereby increasing reliability and ensuring trouble free operation.

Especially for pilot operated solenoid valves, ROTEX offers a solution using Redundant operators in application requiring high availability of equipment to avoid spurious tripping. These are classified as Valves with Redundant Operators. ROTEX can also offer the Redundant Solenoid valves with In build Non Contact type switches to test the system availability for shutdown.


ESD application where spurious tripping due to power failure to the solenoid/ valve malfunction can cause great damage to the safety of the equipment/ material being processed