At Pyropress, we’re proud to have a longstanding history of supporting critical safety infrastructure across the UK’s rail networks. One of our most enduring contributions has been to the London Underground’s Jubilee line, where our ultra-low dual pressure switches have quietly helped protect lives since their initial installation over 25 years ago.
Ensuring safe airflow in tunnel fire conditions
The Jubilee line operates a complex ventilation system designed to manage air movement in the event of a fire. Our specially developed pressure switches were installed to monitor the direction of airflow in high-temperature environments – up to 250°C – ensuring the system correctly switches between supply and extract modes.
These switches were a vital component in Transport for London’s fire safety strategy. By confirming fan direction, they helped prevent air from feeding fires and ensured smoke could be extracted quickly and efficiently from targeted areas.
Designed with extreme reliability in mind, they formed part of the hardwired control logic, not just sensing conditions but acting as safeguards against reversed or incorrect fan operation during critical events.
SIL 2 Certified Titan™ Switches
After more than two decades of dependable service, the time came to replace the original switches. The challenge was clear: maintain the same trusted performance, while meeting the modern standards required for today’s safety-critical systems.
Working closely with our trusted channel partner, Process Instrument Solutions, we delivered the Pyropress Titan™ ultra-low pressure switches, identical in fit, form and function to those supplied in 1997.
These new units provide the same ultra-low differential pressure monitoring, essential for confirming fan operation, with a quantified failure rate of just one per million hours of operation.
Partnering for long-term protection
This project is a testament to what long-term collaboration can achieve. Alongside Process Instrument Solutions, we are proud to continue supporting Transport for London’s safety objectives. Our joint efforts ensure that the infrastructure protecting London’s travelling public remains robust, resilient, and reliable.
For over 70 years, Pyropress has engineered sensing solutions for the most demanding environments. Our switches have earned their reputation for durability through decades of uninterrupted service in some of the UK’s most critical systems.
We are honoured to play a role in Transport for London’s fire safety programme, and we look forward to continuing this important work for many more years to come.
FAQs
What is a SIL 2-certified pressure switch?
A SIL 2-certified pressure switch meets the requirements of Safety Integrity Level 2 under the IEC 61508 standard. This certification ensures the device has a low probability of failure and is suitable for use in safety-critical systems, such as fire protection and ventilation control in transport infrastructure.
What does IEC 61508 mean?
IEC 61508 is an international standard for the functional safety of electrical, electronic, and programmable systems. It defines safety integrity levels (SILs) and provides guidelines for designing systems that reduce the risk of failure in critical applications.
How do pressure switches improve fire safety?
Pressure switches help control airflow in ventilation systems during a fire. By confirming fan direction and pressure levels, they ensure smoke is extracted efficiently and prevent air from feeding the fire, supporting safe evacuation and emergency response.
What makes the Perseus™ pressure switch suitable for critical environments?
The Titan™ pressure switch is designed for extreme conditions, withstanding temperatures up to 250°C and offering ultra-low differential pressure monitoring. Its SIL 2 certification ensures high reliability, making it ideal for safety-critical systems like tunnel ventilation and fire protection.
