Flowserve Limitorque MXa SIL 3 valve actuator

The Limitorque MXa valve actuator from Flowserve has a SIL 3 rating and is designed to provide customers with reliable actuation in critical environments without compromising their safety instrumented systems. The SIL 3 capable rating was obtained from Exida Certification Services after passing rigorous failure mode effects design analysis (FMEDA) and total time in service tests. It carries the safety rating in a one out of two (1oo2) configuration, which requires two actuators and valves to be installed into a SIL 3 rated environment.

Limitorque MXa has multiple features that make it advantageous for critical environments requiring SIL 3 certification, including LimiGard technology that automatically monitors the health of each coded signal and is designed to ensure that no component failure can cause the actuator to move unexpectedly.

Also a part of the LimiGard technology is an absolute encoder designed with a built-in self-test (BIST) capability. The BIST feature confirms the sound operation of the encoder, ensuring the actuator is operating safely.

The MXa SIL 3 capable rating is a standard configuration that includes S1 and S2 contacts as well as the monitor relay. This ensures that the user does not need to utilise external SIL-rated contacts.