Welland & Tuxhorn — Overview
Welland & Tuxhorn AG (part of the KSB Group, founded 1901, Bielefeld, Germany) is one of the world’s leading manufacturers of custom-engineered special control valves for power plants. For over 120 years, they have designed and built critical valves for fossil-fuelled, supercritical, and ultra-supercritical power stations worldwide.
Unlike standard control valves, every Welland & Tuxhorn valve is engineered to order for the specific power plant it will serve — optimized for that plant’s exact operating conditions, pressure, temperature, and flow requirements.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Welland & Tuxhorn AG (KSB Group), Bielefeld, Germany |
| Max Nominal Size | DN1600 (~64") |
| Pressure Classes (PN) | PN 16, 25, 40, 63, 100, 150, 160, 200, 250, 320, 400, 500, 630 |
| Pressure Classes (ANSI) | Class 150, 250, 400, 600, 800, 1500, 2500, 4500 |
| Body Configurations | Straight, Angle, Z-form |
| Body Construction | Forged or cast, with welded studs |
| Connection Standards | DIN, ANSI, or custom |
| Actuation | Hydraulic, electric, pneumatic |
| Noise Level | <85 dB(A) with installed silencers |
| Cavitation | Eliminated by design |
| Maintenance | Easily replaceable interior parts |
Product Range — Power Plant Applications
HP & LP Turbine Bypass Systems
Turbine bypass valves redirect steam around the turbine during startup, shutdown, and load rejection events. Welland & Tuxhorn bypass systems feature integrated motive steam nozzles for optimum steam conversion throughout the load range, and installed silencers for low-noise, low-vibration operation. Available for both HP and LP bypass applications.
Feedwater Control Valves
Full-load feedwater control valves regulate boiler feed flow during normal operation. Low-load startup control valves supply 30–50% of feedwater during startup at higher pressure differences than full load, handling smaller volumes at higher pressure gradients with large adjustment ratios. Forged bodies in straight, angled, or Z-form. No cavitation, no oscillation, noise below 85 dB(A).
Desuperheater & Steam Conditioning Valves
High-temperature injection coolers control steam temperatures in superheaters and reheaters. Integrated systems combining a cooling water control valve with a nozzle head — the valve adjusts injection water pressure according to load. Includes spring-regulated aperture control and externally mixing spray nozzles for precise temperature adjustment at partial load. Forged housing with flange connections or welded studs.
Boiler Startup & Blowdown Valves
Discharge control valves remove boiling water from the boiler drum during startup or low-load operation. On Benson boilers, they maintain constant water level in the startup drum. Forged angled bodies with outlet 2–3 sizes larger than inlet to accommodate evaporation. Hardened sleeve protects the seat outlet from erosion damage.
Condensate Level Control Valves
Regulate condensate level in HP preheaters, discharging condensate into the main or auxiliary condensate system. Available in forged straight, angle, or Z-form configurations with welding ends per DIN or ANSI standards. Designed for precise level control across varying load conditions.
Turbine Control & Emergency Stop Valves
Turbine inlet combination valves regulate steam entry into the turbine across the full operating range. Emergency stop valves provide tight sealing in closed state with minimum flow obstruction when open. Designed for the most demanding turbine protection requirements in fossil-fuelled and supercritical power plants.
Minimum Flow & Cooling Water Injection Valves
Minimum flow control valves protect boiler feed pumps from low-flow damage. Cooling water injection valves regulate cooling water supply to desuperheater systems and other temperature control points. Both are designed for reliable, precise operation under power plant cycling conditions.
Key Design Advantages
- Integrated motive steam nozzle in turbine bypass systems ensures optimum steam conversion across the entire load range
- Installed silencers achieve noise levels below 85 dB(A) — meeting the strictest power plant noise requirements
- Zero cavitation and zero vibration by design — not just mitigated, but eliminated
- Precise flow characteristics with long service life under severe cycling conditions
- Forged valve bodies in straight, angle, or Z-form configurations to suit any piping layout
- Easily replaceable interior parts — service-friendly design minimizes plant downtime
- Low cooling water pressure requirements simplify system design and reduce operating costs
- Sizes up to DN1600 and pressure ratings up to Class 4500 / PN 630 for supercritical applications
- Hydraulic, electric, and pneumatic actuation systems designed and manufactured in-house
- Over 120 years of proven performance in power plants worldwide