POWERTROL
Steam conditioning 500

POWERTROL covers a very wide operating envelope: nominal sizes from DN 15 to DN 800 (½″ to 32″), pressure ratings from PN 16 to PN 400 / ANSI Class 150 to Class 2500, and a temperature range from –10 °C to +650 °C. This spans applications from small industrial steam systems to high-pressure large-scale power plants.

The POWERTROL family is modular and covers all practical injection concepts: in-line body with seat-injection (Type 520), in-line body with stem-injection (Type 510), angle body with stem-injection (Type 550/570), angle body with two-fluid nozzle (Type 560/580), single-fluid nozzles (Type 596), mini desuperheaters (Type 595), separate desuperheaters (Type 3), and an in-line body with two-fluid nozzle. A Z-body version is also available. The right concept can therefore be selected for every combination of steam flow rate, steam pressure and temperature, and cooling water pressure.

Two-fluid nozzles are used when the steam flow rate varies over a wide range, the cooling water pressure is restricted or where the available evaporation path is short. A motive-steam jet atomises the cooling water into very fine droplets so that they evaporate quickly and completely. The result: short evaporation distances, high control accuracy even at low loads, and no droplet carry-over into the downstream piping – ideal for the flexible operating modes of modern power plants.

The trim uses perforated throttling elements and cage-plug/cage-seat combinations that split the flow into many small jets, significantly reducing the sound pressure level. Multi-stage pressure-reduction concepts, customised hole patterns and low-noise cages are engineered specifically to the flow conditions, the required sound level and the rangeability. POWERTROL therefore meets even the strictest noise regulations in power plant environments.

The POWERTROL design enables precise and stable outlet temperature control across the full load range. The injected water is metered through a separate spray water control loop. Combined with ARCA’s intelligent positioners (ARCASMART, ARCAPRO®), set-point deviations of just a few Kelvin can be maintained even under varying load conditions.

For safety-relevant duty, POWERTROL can be supplied with a SIL-compliant quick-closing function. A strainer can be integrated on the steam inlet to keep foreign bodies out of the system and protect both the trim and downstream components from damage. Optionally, bellows-sealed stems, redundant end-position monitoring and safety-rated pilot equipment (solenoid valves, boosters) can be added.

For typical operating temperatures, cast steels and creep-resistant forged steels are available – from cast carbon steel 1.0619 / A216 WCB for moderate temperatures to creep-resistant grades 1.7357, 1.7379 or 1.4931 / A217 WC9, A217 C12A for superheated steam, all the way to special grades for high-pressure service. Material selection is made case by case, taking into account temperature gradients, cyclic loading and required service life.

Pneumatic diaphragm actuators (Series 812 and 811) are used as standard, providing high actuating forces and fast response times with a specified fail-safe position. Pneumatic piston actuators (Series 814 or 812 DWK) as well as electric and electrohydraulic actuators are available as options. Quick-closing functions, spring-return action and double-acting configurations can be combined to suit the safety requirements.

For demanding steam conditioning duty, the digital ARCAPRO® positioner with extensive diagnostic and communication capabilities (HART®, PROFIBUS PA®, FOUNDATIONTM FIELDBUS) is recommended. Travel, thrust, valve signature and stroking behaviour can be continuously monitored, enabling predictive maintenance and maximum plant availability.

The body is engineered to handle high temperature gradients during start-up and cyclic thermal load. Special wall-thickness modelling, optimised transition radii, qualified materials and a proven body design provide long service life even in modern, flexibly operated power plants with frequent start/stop cycles.

The Type 595 is a compact desuperheater for small flow rates. It is used wherever installation space is limited or where small partial steam streams have to be conditioned – for example in auxiliary systems, heating lines or small industrial turbines. Despite its compact design, the mini desuperheater achieves high control accuracy and short evaporation distances.

Typical applications include turbine bypass systems, live-steam and superheated-steam conditioning in steam power plants, start-up and bypass stations, pressure-reducing stations for process steam in chemical and petrochemical industries, waste-to-energy plants, pulp and paper, as well as concentrating solar power and biomass plants. In short: wherever live steam needs to be conditioned precisely and safely in temperature and pressure.

The full ARCA service portfolio is available for POWERTROL: ARCAlaunch for commissioning including flushing services, ARCAcare for preventive maintenance, ARCAsafe for spare-parts availability, ARCA24/7 for round-the-clock telephone support, as well as theoretical and practical training sessions. Sizing is performed in ARCA-VENA; via the ARCAonsite platform, all documents are accessible by QR code directly at the valve.

POWERTROL is designed in accordance with the Pressure Equipment Directive 2014/68/EU; the body is engineered to EN 12516-2 / ASME B16.34. Optional designs to AD 2000, ASME B31.1 / B31.3, TRD 110 and SIL-rated quick-closing functions are available.