PNEU-TRIP®

Electro-Pneumatic Trip System For General Purpose Steam Turbines

Drake Controls PNEU-TRIP electro-pneumatic trip block
A complete PNEU-TRIP electro-pneumatic trip block, built and tested by Drake Controls.

PNEU-TRIP® is a state-of-the-art safety system designed for the protection of steam turbines. Each system includes a pneumatic trip block with SIL3-certified solenoid valves and SIL capable pneumatic actuator.   When coupled with a Woodward ProTech SX, GII or TPS electronic overspeed detection system, PNEU-TRIP provides one of the most advanced, safe, high speed and reliable turbine protection solutions available.

The system features the patented technology that employs a unique pneumatically engaged travel stop for partial stroke testing. While a typical pneumatic trip system falls short in exercising the emergency trip solenoid valves and actuator springs while introducing risks of tripping the turbine during partial stroke tests. If a turbine trip condition is detected during the test, the travel stop is immediately disengaged allowing for quick and safe shutdown of the turbine. PNEU-TRIP components are designed to be fail-safe upon loss of electric or pneumatic power and are online replaceable in TMR configurations.

Each trip actuation system can be furnished either standalone or as a complete safety solution, integrated with a Woodward electronic overspeed detection device such as ProTech SX or ProTech TPS. PNEU-TRIP also seamlessly integrates with the existing overspeed detection system, such as the ProTech-GII.

ProTech device is supplied in an industrial enclosure designed and fabricated to NEMA/UL standards by Drake Controls. The enclosure meets requirements of both area classification and ambient conditions of each specific installation.

Drake-built NEMA enclosure for a PNEU-TRIP system
Each PNEU-TRIP ships in a Drake-built NEMA / UL enclosure rated for the area classification of each installation.

Drake Controls also provides optional speed probes with mounting bracket and speed tooth gear.  

Benefits

  • Increase overall reliability of turbine trip system 
  • Reduce risks of overspeed trip failures that can lead to equipment damage and loss of life 
  • Eliminate human safety risks and high costs of mechanical overspeed trip tests  
  • Minimize insurance premiums 
  • Eliminate downtime and loss of production due to failures of mechanical trip system components  
  • Comply with latest API standards
  • Accurately validate trip valve movement during PST
  • Loosen buildup of deposits on valve stem
  • Test trip solenoids and actuator springs online
  • Obtain access to trip system diagnostic data 

Features

  • Complete Replacement of Mechanical Overspeed Trip
  •   Fast and Accurate Pneumatic Actuation
  • Overall Trip Cycle Times below 100 Milliseconds*
  •   Seamless Integration with Woodward ProTech 
  •   SIL-rated Safety System Components **
  • High Safety (1oo2) and High Availability (2oo3) SOV Blocks
  • Models with Online Replaceable Components
  • Linear or Rotary Actuation Assemblies
  • Pre-Configured & Tested, Ready to Be Installed on Turbine Chest/ Inlet
  • No Turbine Disassembly Or New OEM Components Required
  • UL/CSA/FM Approved, Class I, Div. I/II, Groups A,B,C & D Electric Components

Installation

A factory-assembled and tested PNEU-TRIP linear trip valve actuation system is mounted directly on the steam chest and coupled to the OEM trip valve.

PNEU-TRIP mounted on a steam turbine trip valve
A linear PNEU-TRIP actuation system mounted on the steam chest and coupled to the OEM trip valve.

PNEU-TRIP quarter-turn rotary actuation system is supplied fully assembled with a zero-leakage quarter turn valve. PNEU-TRIP rotary trip valve system is mounted on turbine inlet flange.    

Controls & Instrumentation

  • Digital speed governors
  • Compressor control systems
  • Custom control panels built to UL and NEMA standards
  • Magnetic pickups
  • Speed sensing gears
  • Governor valve actuators

Services

  • Systems engineering
  • Site surveys
  • Installation assistance
  • Site acceptance tests
  • Startup and commissioning
  • Technical Support Call Center
  • 24-hour response

*  Will depend on actuator size/model and length of tubing for remote-mount trip block models

** Rotary actuators are SIL3 capable. Linear actuator SIL certification pending


Interested in PNEU-TRIP?