Woodward QuickTrip Electro-Hydraulic Trip Block Assembly Introduction

Introduction

The QuickTrip trip block assembly is designed for use in gas or steam turbine shutdown systems for quick

and reliable dumping of the turbine’s trip oil header. This integrated trip block assembly is intended for

use on mechanical-drive or generator-drive gas or steam turbines that use low-pressure (up to 34.5 bar /

500 psi) hydraulic trip oil headers.

The QuickTrip’s fault tolerant design makes it ideal for critical gas or steam turbine applications, where

turbine up-time and availability are essential. The trip block assembly’s 2-out-of-3 voting design provides

users with a very high level of system reliability as well as compliance with industry standard API-670.

This trip block assembly is designed to allow turbine controls and/or turbine safety systems to quickly

dump (bleed off) hydraulic header pressure during emergency trip or normal trip conditions. When applied

in conjunction with Woodward’s ProTechTPS logic solver, the QuickTrip allows users to independently

test each trip leg to verify operation and trip time. API-670 5th edition requires that all components except

for the final element (trip valve) shall be routinely tested while the turbine is in operation.

With the use of trip solenoids, which respond in less than 50 milliseconds, the QuickTrip is designed for

gas or steam turbine trip systems where it is imperative that the entire trip system shut the system trip

valve as quickly as possible.

The QuickTrip’s robust design (corrosion resistant materials, three independent moving rotary valves, and

self-cleaning port design) makes it optimal for challenging applications where dirty or contaminated oil

may be present.

The QuickTrip is certified for use in IEC61508 based turbine safety systems, and when paired with the

Woodward ProTechTPS, can be applied into systems that require a “Safety Integrity Level – 3” rating or below.

Designed for use in new or retrofit turbine packages, the QuickTrip’s compact package size allows it to be

located near the turbine and trip & throttle valve, minimizing trip header piping and related system delays.

Each trip leg includes bright position indication LEDs (run & trip), allowing turbine operators to quickly

verify system status locally near the turbine, as well as integrated limit switches for safety system and

plant DCS status and health validation.

The QuickTrip is an IEC61508 safety certified electro-hydraulic trip block assembly designed for use in

gas or steam turbine shutdown systems for quick and reliable dumping of the turbine’s trip oil header.

This trip block assembly’s 2-out of-3 voting design provides users with a high level of system reliability as

well as compliance with industry standards like API-670. API-612. and API-611.

This trip block assembly is housed in a fully integrated package, which includes three patented dirt

tolerant rotary trip valves. These valves are connected to provide redundant two-out-of-three based voting

to ensure that a failure of any one component (electronics module, valve, wiring, connector, etc.) does not

result in a nuisance trip condition. The QuickTrip’s modular design also allows users to replace critical

components (electrical module, solenoid, wiring, etc.) while the turbine is operating on-line.

Designed to quickly and reliably bleed off trip oil header pressure, at least two of the QuickTrip's three

rotary solenoid valves must be de-energized to open a bleed path from the trip oil header to system drain.

The QuickTrip accepts one or two (redundant) 24 VDC power sources to power each solenoid, and uses

three independent discrete input shutdown commands from a safety logic solver like the Woodward

ProTechTPS (independent voted models) to test and control each solenoid valve.

Because gas and steam turbines are often used in hazardous locations where flammable gases may be

present, the QuickTrip is designed to be mounted next to the turbine and is certified for use in Zone-1 or

Zone-2 (Class 1 or Class 2) hazardous locations.

When packaged with a Woodward ProTechTPS safety logic solver, the ProTechTPS performs the

required routine safety system diagnostic tests to verify unit operation while the turbine is on-line. The

proof test trip time response monitoring and logging ensures the total turbine safety system can respond

fast enough to safely shutdown the turbine.

The total installed cost for this fully integrated trip block assembly is low because it has been completely

assembled and tested at the factory. This greatly reduces OEM and end-user fabrication time, installation

time, and testing time.