Electro-Pneumatic Trip System For General Purpose Steam Turbines
PNEU-TRIP® is a safety system designed to protect steam turbines. Each system includes a pneumatic trip block with SIL3-certified solenoid valves and a SIL capable pneumatic actuator. When coupled with a Woodward ProTech-SX, ProTech-GII, or ProTech TPS electronic overspeed detection system, PNEU-TRIP provides a safe, high-speed, and reliable turbine-protection solution.
The system uses patented technology with a pneumatically engaged travel stop for partial stroke testing. A typical pneumatic trip system does not exercise the emergency trip solenoid valves and actuator springs and can introduce a risk of tripping the turbine during a partial stroke test. If a turbine trip condition is detected during the test, the travel stop disengages immediately, allowing a quick and safe turbine shutdown. PNEU-TRIP components are designed to fail safe upon loss of electric or pneumatic power and can be replaced online in TMR configurations.
Each trip actuation system can be furnished as a standalone system or as a complete safety solution integrated with a Woodward electronic overspeed detection device such as ProTech-SX or ProTech TPS. PNEU-TRIP also integrates with existing overspeed detection systems such as ProTech-GII.
The ProTech device is supplied in an industrial enclosure designed and fabricated by Drake Controls to NEMA/UL standards. The enclosure meets the area-classification and ambient-condition requirements 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 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