DRAG® VLNTurbine Bypass Valve for Hot Reheat Bypass Applications

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s2 VLN delivers superior pressure reduction and

temperature control in a compact, high capacity steam conditioning control valve.

CCI’s Unrivalled Power Expertise

CCI is the world’s leading supplier of severe service control valves and is

unrivalled in its portfolio of products and service. For more than 80 years,

CCI has worked with power plant designers and operators to improve

plant performance, efficiency, and reliability.

The VLN is a high performance intermediate pressure (also known as

HRH to Condenser) turbine bypass valve and low pressure turbine bypass

valve for combined cycle plants, conventional fossil fired plants and larger

industrial power plants.

Technology and design features from CCI’s proven range of turbine

bypass and steam conditioning valve are integrated into the VLN design.

With a modular valve body and desuperheater design it can be adapted

for a wide range of pipe sizes and valve installations.

Featuring CCI’s patented DRAG® technology, proven desuperheating and

advanced actuation and control equipment the VLN is designed to meet

the customer specifications.

The VLN is a proven design backed by world class expertise.

The VLN is a modular design. It can be configured as a flow-to-close or flow-to-open valve in an angle or globe pattern, with ASME or EN pressure rating.

n Proven Design

n Improved Plant Efficiency

n Operation to 620°C (1150°F)

n Low Noise DRAG® Technology

n Advanced Actuation and Control

n Customized Desuperheating

n Flexible Modular Design

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3Hot reheat bypass application discussion

The Hot Reheat Turbine Bypass System

The HRH bypass is used during startup, shutdown, and turbine trip to

bypass steam around the HRH steam turbine.

The bypass valve and desuperheater simultaneously reduce steam pressure

and temperature to a level that is safe for the condenser.

These adjustments in pressure and temperature can generate high

velocities in the steam pipe as well as large thermal gradients and stresses

in downstream piping.

Some of the common problems associated with these conditions are:

n Severe vibration; which can cause damage to the valve and

surrounding hardware

n Excessive noise; which can lead to penalties, restricted output, or

mandatory plant down-time

n Sticking of trim; which can lead to damaged upstream and

downstream equipment

n Thermal stress cracks in valve trim, outlet, and the downstream

pipe.

These problems are caused by a combination of design, installation, and

control issues. They can lead to delays in plant commissioning; unreliable

startup operation; expensive repair and replacement costs as well as

damage to other major systems in the power plant; and an increased risk

to plant personnel.

The Valve Doctors®: Unsurpassed Technical Global Expertise

CCI knows that engineering, design, and service go hand in hand in

providing complete solutions with unequivocal results. That’s why CCI

products are backed by the world class expertise of The Valve Doctors®

and Engineering teams.

The CCI Valve Doctors® designed the VLN as a modular product range

for IP steam bypass applications making it the most flexible platform

for demanding project specifications. At CCI, The Valve Doctors®

use their extensive knowledge and experience to help you select the

right technology for the application, and to help you with important

recommendations for system installation and control.

Preventative Maintenance Program for Turbine Bypass Systems

CCI provides installation and preventitive main-tenance manuals

Valve Doctors and engineering team is here to serve you

CCI’s HRH valve in operation

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s4

Graphite Balance Seal

Provides Class V leakage

across the seal with

balanced trim, excellent trim

guiding , and resistance to

vibration and galling.

DRAG® VLN Highlights and Features

Trim Options

A low-noise

drilled hole

cage or a multi-

stage DRAG®

disk stack for

best-in-class

noise perfor-

mance and

control.

Full Thermal Compensation Design

Resistant to thermal shock.

High Temperature Operation

For use with steam

temperatures

up to 620°C (1150°F)

Tight

Shutoff

Up to MSS-

SP61 with

pressurized

seat designPart Description < 550°C < 580°C < 620°C

Body/Bonnet A217-WC9/A182-F22 A217 –C12A/A182-F91 A217 –C12A/A182-F92

Seat Ring X20CrMoV12 1 X20CrMoV12 1 A182-F91

Plug 1 X20CrMoV12 1 IH X20CrMoV12 1 IH A182-F91 Stellite 6

Stem B637-718 B637-718 B637-718

Cage 11CrMo910Bath Nitrided

X20CrMoV12 1Plasma Nitrided

A182-F91HVOF Stellite

DRAG® Disk Stack B637-718 B637-718 B637-718

1 DRAG® valves use A182-F91 Stellite 6 for plug material for all temperature ranges.

Cast or Forged Body

Cartridge Trim

Optional bolted trim

design for ease of

assembly/disassembly

in horizontal

installations.

5

Spraywater Manifold System

Multiple attemperation

injection points with

single water supply source

connection.

VLN230 VLN280 VLN340 VLN400 VLN450

Trim Size 230 mm 280 mm 340 mm 400 mm 450 mm

Max Capacity Kv (Cv)

1250 (1450) 1960 (2270) 2730 (3150) 3830 (4430) 4930 (5700)

Pressure Class ASME B16.34 Class 900/EN 12516-1 CL 900

Typical inlet connection

300 - 500 mm 12” – 20”

350 - 550 mm 14” – 22”

400 - 600 mm 16” – 24”

450 – 650 mm 18” – 28”

500 – 700 mm 20” – 30”

Typical outlet connection

400 – 1500 mm 16” – 60”

500 – 1500 mm 20” - 60”

600 -1500 mm 24” – 60”

600 – 1500 mm 24” – 60”

600 – 1500 mm 24” – 60”

Outlet Diffuser

Reduces system noise and provides

flow profiling to improve secondary

atomization of spraywater.

Spring-Loaded Spraywater

Nozzle Desuperheaters

Mounted directly to outlet,

eliminating need for

additional piping sections.

Coolmist® available for

improved desuperheating

control.

Quick-Change Trim

Minimizes service time.

No trim parts are welded or

screwed into the valve body.

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6 Patented DRAG® technology and world class desuperheating

DRAG® Technology Eliminates Problems with Noise and

Vibration

The VLN is available with DRAG® technology. DRAG® technology is the

best solution for extending trim life and improving system reliability in

severe service applications.

The benefits of CCI DAM and DAM-D style desuperheaters include:

n Nozzles that are circumferentially wall mounted to ensure and even

and full distribution of spraywater over the cross section of steam.

n Small water droplets of less than diameter 250 microns is assured

regardless of spraywater flow.

n Steam flow profiling in DAM-D designs minimizing the risk of

thermal shock to the outlet of the valve and downstream pipe work.

n DAM-D designs features an integral inlet diffuser, which straightens

steam flow prior to water injection, increases steam flow at the point

of water injection, and limits valve outlet noise.

n A selection of spring loaded nozzles tailored to optimize system

performance and provide long service life.

DRAG® technology controls trim exit velocities to safe level, and

eliminates the root cause of control valve problems. The DRAG® disk

stack uses a unique multi-stage, multi flow path design. CCI can provide

this technology both within the control valve trim and in the final

element in an ACC duct or vent to atmosphere system.

Severe Service Desuperheaters

The VLN is available with multi-stage desuperheating for high-turndown

applications, and with CCI’s revolutionary Coolmist® spray nozzles which

use advanced atomization technology to increase the efficiency of spray

water evaporation and provide better system control.

The benefits of CCI DAM and DAM-D style desuperheaters include:

n Nozzles that are circumferentially wall mounted to ensure and even

and full distribution of spraywater over the cross section of steam

n Small water droplets of less than diameter 250 microns is assured

regardless of spraywater flow

n Steam flow profiling in DAM-D designs minimizing the risk of

thermal shock to the outlet of the valve and downstream pipe work

n DAM-D designs features an integral inlet diffuser, which straightens

steam flow prior to water injection, increases steam flow at the point

of water injection, and limits valve outlet noise

n A selection of spring loaded nozzles tailored to optimize system

performance and provide long service life

DRAG® multi-path multi-stage technology

Radial injection DAM desuperheater with spring-loaded nozzles

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7Highly reliable, fast, accurate pneumatic and hydraulic actuators provide superior system control

Control and Reliability for Severe Service Applications

HRH bypass systems require fast, accurate, and reliable positioning

actuation. CCI’s QuickTrak® and FastTrak® positioning systems are

recommended for use with the VLN for demanding HRH turbine bypass

applications. Both solutions:

n Can be remote mounted preventing damage due to heat and

vibration

n Eliminate the need for boosters which decreases tuning time

n Provide industry leading dynamic performance

The QuickTrak® has a high-capacity pneumatic servo valve which provides

the same speed and precision as hydraulics, but using normal plant

compressed air. FasTrak® is a 2-wire high capacity smart positioner that

provides flow capacity equivalent to a traditional smart positioner with

boosters.

Remote mounted QuickTrak® high speed positioning system provides total protection from vibration

FasTrak® Positioner

Servovalve fully remote

mounted

Actuator supply port – high capacity,

no boosters

QuickTrak® controller fully remote mounted

Balluff transmitter no linkages

Contact us at: vln@ccivalve.com

For sales and service locations worldwide, visit us online at: www.ccivalve.com

Throughout the world, customers rely on CCI companies to solve their severe service control valve problems. CCI has provided custom solutions for these and other industry applications for more than 80 years.

DRAG is a registered trademark of CCI.©2010 CCI 943 01/10 #K