Control Valve for High Temperature and High Pressure

We design, develop and supply high performance control valves, safety valves, other valves and flow control trim used in power plants and plant facilities. In particular, we succeeded in localization of Q-Class control valve(AOV), all of which had been imported from abroad.

Reference List of Control Valve

Category Field Clients Service Q’ty
Domestic (Korea) Nuclear Power Plants Kori, Yeonggwang, Ulchin, Wolsong Feed water heater control valve, etc. 263
Thermal Power Plants Seoincheon, Boryeong, Yeongheung, etc. Boiler feed water control valve, etc. 391
Refinery and Chemical Plants LG Chemical, AERO PHE, etc. Flow control valve, etc. 55
Shipbuilding and others KAERI, etc. High pressure flow control valve, etc. 64
Overseas Thermal Power Plants Jordan Thermal Power Plant in Syria High pressure feed water control valve, etc. 28
Nuclear Power Plants Baraka NPP in UAE Control valve for feed water heater, etc. 62
Total 863

VIV Reference List

Unit : EA

Category Domestic Overseas Total
Construction Maintenance EPC Construction


GLOBE 148 124 173 184 145 9 207 990
BALL 4 16 12 32
BUTTERFLY 14 22 34 28 98
GATE 13 8 27 4 52
PCV 1 1 2
PRV 10 7 10 3 30
PSV 16 7 16 7 12 58
CHECK 4 1   5
44 44
PLUG 5 5
Angle 6 6
Total 174 124 222 307 230 30 235 1322
(TPP : Thermal Power Plant, NPP : Nuclear Power Plant)


New Excellence Product(NEP) Certified by Korea Government

Product Name

3D Multi-stage Trim Control Valve with Air-Operated Actuator

Certified Scope

Less than 20″, Less than 2,500 lb


3D Multi-stage Trim control valve with air-operated actuator suitable to high pressure condition was developed using so unique technology in the world that Korea government certificated it as a ‘NEP’(New Excellent Product).
  • 3D Multi-stage Trim with three-dimensional and tortuous multi-flow paths structure using the latest patented technology
  • flow velocity limiting and adjusting function of trim part (less than 23 m/sec.)
  • precise linear control without flow dead band
  • reduced noise level with consistent cross section over flow paths (less than 80 db)
  • improved trim volume ratio for preventing valve from being damaged (less than 90%)
  • reduced valve damage through the separation of flow regulating and sealing function (maintenance interval: 3 years, competitor’s products : 1~2 years)


    Power plant
  • Reheat and superheat attemperator spray
  • Main and booster feed pump recirculation
  • Condensate booster pump recirculation
  • Turbine seal pressure control
  • Steam generator blowdown
  • Pressurizer PORV
  • CVCS letdown, etc.
    Petrochemical plant
  • Production chokes
  • Separator-level control
  • Gas lift/injection
  • Injection pump recycle
  • Hot gas bypass
  • Feedwater pump recirculation
  • Steam header pressure control, ect.


Applied Patented Technology


Design Technology

Trim Design

    Parameters(Factors) for Trim Design
  • Loss coefficient for valve shape
  • Loss coefficient due to trim
  • Reynolds number
  • Temperature, pressure and density of fluids
  • Flow characteristics curve versus valve travel
  • Fluid velocity


    Design Considerations of Trim for High Differential Pressure Service(High Performance)
  • Shape and size of valve
  • Size of flow path and number of Stage
  • Shape of flow path(resistance coefficient)
  • Thickness of cylinder or disk
  • Flow coefficient(Cv valve)
    ※Type of fluid shall be considered for the determination of flow coefficient valve(apply ISA 75.01).



    Limiting Valve for the Fluid Velocity(Energy)
Condition Applied Based on Kinetic Energy Equivalent Velocity of Water
psi kPa ft/s m/s
Single Phase Fluid 70 480 100 30
Cavitation and Two Phase Fluid 40 275 75 23
Vibration-sensitive System 11 75 40 12


Considerations for the Design(Selection) of Actuator

  • Force due to the Fluid Pressure
  • Weight of Plug
  • Friction Force of Packing
  • -Packing Material
    -Diameter of Stem
  • Spring Force
  • Frictional Force of Balance Seal
  • -Balance Seal Material
    -Diameter of Trim
  • Shutoff Force
  • -Seat Leakage Class
    -Diameter of Seat


Analysis Technology

CFD Analysis

  • Analyze fluid velocity, pressure and flow pattern at valve body, seat ring and trim using ANASYS CFX or FLUENT.

Structural Analysis

  • Analyze the stress distribution due to operating load combination using ANSYS, NASTRAN and LS-DYNA, review the interference of components by calculating the displacement due to stress and validate the structural integrity and the design suitability based on the requirements of ASME and KEPIC.

Seismic Analysis

  • Perform the analysis to determine whether the natural frequency exceeds 33 Hz for kinds of materials of each component and for structural shape of control valve and validate the structural integrity against seismic load(Harmonic Analysis).


Testing & Qualification

Performance Qualification

  • operability Test

Elapsed Time vs. Valve Travel/Pressure


Control signal vs. Valve Travel

Equipment Qualification (ASME QME-1, IEEE 323, 344 and 382)

Qualification Item Test Condition and Method
Visual Inspection Inspect appearance of equipment visually
Basic Performance Test Acquiring basic research for equipment
Radiation Aging Test 1.1X104 Gy irradiation
Accelerated Thermal Aging Test Validating the durability of equipment over forty(40) years Pressure Cycle Test
Pressure Cycle Test Applying pressure of 65psig for fifteen(15) times
Vibration Aging Test 5Hz~100Hz
Seismic Test SSE, OBE
DBA Test LOCA, MSLB, etc.




Seat Leakage Classification of Control Valve(ANSI B16.104)

Leakage Class-Designation Maximum Leakage Allowable Test Medium Test Pressure
Reference value specified by user and manufacturer - As specified by manufacturer
0.5% of rated capacity Air or Water at 10~52℃ 45~60 psig or max. operation differential, whichever is lower
0.1% of rated capacity As above As above
0.01% of rated capacity As above As above
0.0005ml per minute of water per inch of port diameter per 1psi differential Water at 10~52℃ Max. rated differential pressure across valve plug


Fluid Dynamic Change of Valve

Difference of Pressure Recovery of Ball Valve and Globe Valve


Flow Characteristics Curve and Trim Characteristics of Control Valve

Selection of optimum trim considering flow change due to pressure drop across valve and other piping component in control system.


● Linear Flow Characteristic
Flow rate is directly proportional to the amount
of Valve Plug Travel
  • At 50% of rated travel, flow rate is 50% of maximum flow.
  • At 80% of rated travel, flow rate is 80% of maximum flow.
Applicable Valve
  • Liquid Level Control
  • Flow Control within Specific Range
Valve Used
  • D/A Level Control Valve
● Equal Percentage Characteristic
For equal increments(%) of valve plug travel,
equal percentage of the flow changes.
  • At 50% of rated travel, flow rate is 18% of maximum flow.
  • At 80% of rated travel, flow rate is 50% of maximum flow.
Application Valve
  • Pressure Control
  • In case of high Pressure Drop
Valve Used
  • BLCV
● Modified Parabolic
Between Liner and Equal Percentage

Precise throttled action at low flow and similar flow to Linear characteristic at high flow
● Quick Open Characteristic
Valve that needs quick opening
  • At 50% of rated travel, flow rate is 80% of maximum flow.
  • At 80% of rated travel, flow rate is 95% of maximum flow.
  • Relief Valve


Retrofit & Up-Grade

Retrofit & Up-Grade(Grade)
State of the art maintenance technique for improving the thermal efficiency due to leakage stoppage and the extension of life time and maintenance interval as well as the better performance(control ability, anti-erosion and corrosion and anti-leakage) than existing control valves through the redesign, repair and replacement of critical part(trim part) using hydro-dynamic technology
Possible Targets for Retrofit & Up-Grade
  • Most of the valves designed prior to the year of 1990.
  • Valves whose service conditions such as flow and differential pressure are changed.
  • Valves having short replacement interval of their components(which require a lot of spare parts).
  • Valves having lots of erosion, wear and damage of components.
  • When requested by users.
  • Valves being expected of better performance with new design technology.
Necessity of Retrofit & Up-Grade
  • To Safety the customer’s desire for new high quality products.
  • To be prepared for the obsolescence of existing products and to meet the requirement for the increased level of reliability
  • Retrofit & Up-Grade technology with the optimum design of major component(trim part) is available.
Applicability of HARMONY Trim to Retrofit & Up-Grade
  • Excellent Retrofitability by optimum design(reduction of cage volume ratio).
  • Structural mechanics design to protect from inflow of foreign materials.
  • Leakage blockage by plug & seat design with double-blocking structure.
  • Reduction of maintenance cost by performing retrofit without any modification of valve body and actuator.
  • Clearance of the problem such as leakage, noise and vibration, ect. And increase of durability.
  • Improvement of control performance and reliability.


Application of Trim Characteristics Considering System




Target for Performance Improvement

    Power Plant Problem Valves
  • MFWP & COP Recirculation valve
  • HTR Drain Dump/Control valve
  • Boiler(S/G) Pressure Control valve
  • Main Steam Dump valve



    Feedwater Control Valve Solutions
  • Characterized Harmony Trim to eliminate cavitation and vibration
  • Cylinder operator for high force loads for optimum control
  • Flow to close design uses disk stack to protect critical guide and seating surfaces



Other Application

Noise reduction device in discharge side of the Pressure relief valve
Noise reduction by orifice or alternative design
Back-pressure device of the high pressure drop(Recirculation) valve
Integration of the overpressure protective and control function


Plasma Coating

Republic Korea  Utility Model No. 20-415452
Title  Valve Device Forming Carbon Ion Implantation Layer on Surface
  • Carbon ion implantation layer of uniform thickness is formed on the surface of part using the Plasma Source Ion Implantation(PSII) to strengthen the hardness, abrasion resistance and mechanical characteristics.
  • Fluid leakage is prevented by protecting major valve components(trim part, plug, seat ring and cage) from the damage(erosion, corrosion, wear, galling and scratch) due to interaction of components and fluid kinetic energy occurred by differential pressure and high fluid velocity.
    Pictures showing the Coating Application


General Product

Product with Plasma Coating



    Result of Coating Application

Coating Thickness Hardness(Hv) Result
Stellite #6 2~3 mm 75 Steam cutting
Plasma Coating 10μm 2,000 Nothing