DRAG VLN Turbine Bypass Valve for Hot Reheat Bypass Applications

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1 DRAG VLN Turbine Bypass Valve for Hot Reheat Bypass Applications

2 VLN delivers superior pressure reduction and temperature control in a compact, high capacity steam conditioning control valve. 2 n Proven Design CCI s Unrivalled Power Expertise n Improved Plant CCI is the world s leading supplier of severe service control valves and is Efficiency n Operation to 620 C (1150 F) CCI DRAG VLN Turbine Bypass Valve for Hot Reheat Bypass Applications n Low Noise DRAG Technology n Advanced Actuation and Control n Customized Desuperheating n Flexible Modular Design 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-toopen valve in an angle or globe pattern, with ASME or EN pressure rating.

3 Hot reheat bypass application discussion 3 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. CCI s HRH valve in operation Valve Doctors and engineering team is here to serve you Preventative Maintenance Program for Turbine Bypass Systems 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: Severe vibration; which can cause damage to the valve and surrounding hardware Excessive noise; which can lead to penalties, restricted output, or mandatory plant down-time Sticking of trim; which can lead to damaged upstream and downstream equipment 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. CCI DRAG VLN Turbine Bypass Valve for Hot Reheat Bypass Applications CCI provides installation and preventitive maintenance manuals

4 4 DRAG VLN Highlights and Features Cast or Forged Body Trim Options CCI DRAG VLN Turbine Bypass Valve for Hot Reheat Bypass Applications Full Thermal Compensation Design Resistant to thermal shock. Graphite Balance Seal Provides Class V leakage across the seal with balanced trim, excellent trim guiding, and resistance to vibration and galling. High Temperature Operation For use with steam temperatures up to 620 C (1150 F) Part 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 B B B Cage Cartridge Trim Optional bolted trim design for ease of assembly/disassembly in horizontal installations. 11CrMo910 Bath Nitrided X20CrMoV12 1 Plasma Nitrided A182-F91 HVOF Stellite DRAG Disk Stack B B B DRAG valves use A182-F91 Stellite 6 for plug material for all temperature ranges. A low-noise drilled hole cage or a multistage DRAG disk stack for best-in-class noise performance and control. Tight Shutoff Up to MSS- SP61 with pressurized seat design

5 5 Quick-Change Trim Minimizes service time. 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 CL 900 Typical inlet connection Typical outlet connection mm mm mm mm mm mm mm mm mm mm No trim parts are welded or screwed into the valve body. Spraywater Manifold System Multiple attemperation injection points with single water supply source connection. 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. CCI DRAG VLN Turbine Bypass Valve for Hot Reheat Bypass Applications

6 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: DRAG multi-path multi-stage technology Nozzles that are circumferentially wall mounted to ensure and even and full distribution of spraywater over the cross section of steam. Small water droplets of less than diameter 250 microns is assured regardless of spraywater flow. Steam flow profiling in DAM-D designs minimizing the risk of thermal shock to the outlet of the valve and downstream pipe work. 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. 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: Radial injection DAM desuperheater with spring-loaded nozzles Nozzles that are circumferentially wall mounted to ensure and even and full distribution of spraywater over the cross section of steam Small water droplets of less than diameter 250 microns is assured regardless of spraywater flow Steam flow profiling in DAM-D designs minimizing the risk of thermal shock to the outlet of the valve and downstream pipe work 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 A selection of spring loaded nozzles tailored to optimize system performance and provide long service life

7 Highly reliable, fast, accurate pneumatic and hydraulic actuators provide superior system control 7 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: Can be remote mounted preventing damage due to heat and vibration FasTrak Positioner Servovalve fully remote mounted QuickTrak controller fully remote mounted Eliminate the need for boosters which decreases tuning time 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. Balluff transmitter no linkages Actuator supply port high capacity, no boosters Remote mounted QuickTrak high speed positioning system provides total protection from vibration CCI DRAG VLN Turbine Bypass Valve for Hot Reheat Bypass Applications

8 Contact us at: For sales and service locations worldwide, visit us online at: 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 CCI /10 #K