Phone: +44 1462 480121
Address: Unit 25, Business Centre West,
Avenue One, Letchworth Garden City, Hertfordshire, SG6 2HB
United Kingdom

STL Power & Process Controls – Energy Under Control

Call Us: +44 1462 480121

Welcome to STL Power and Process Controls Ltd

Established in 1998 by RTK GmbH, we are now a privately owned supplier of valves, instrumentation and flow control products. With our depth of experience we are able to assist in specifying the correct product for any given application and can also assist in designing systems for optimum efficiency. Our range of products and supply partners is comprehensive, meaning that we can deliver packaged solutions tailored to our customer’s needs.
We are interested in your problems and are proud of the service we provide to our customers.

Our Markets

✓ Food & Beverage
✓ Power Generation
✓ Petrochemical
✓ Industrial & Process
✓ Industrial Refrigeration
✓ Pharmaceuticals
✓ Chemical
✓ Marine
✓ Hospitals & Healthcare

Our Services

✓ Valve Sizing
✓ Process System Design
✓ Site Surveys
✓ Technical Support
✓ Feasibility Design Studies
✓ Turnkey Solutions
✓ Maintenance & Service
✓ Overhaul & Repair
✓ Installation & Commissioning
✓ Consultancy

Officially Partnered With

Our Products

Control Valves

A flow control valve regulates the flow or pressure of a fluid. Control valves normally respond to signals generated by independent devices such as flow meters, pressure transducers or temperature transmitters.

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Industrial Process Valves

Industrial process valve regulates the flow or pressure of a fluid. The pressure reducing valve is a self-operated regulator without auxiliary energy for controlling the downstream pressure to the adjusted set point.


Electric actuator for modulating/on/off control valves. Separate force and limit switch for both directions, Protection rating IP 65, valve position indicator, manual hand wheel, self-locking and stall-proof stop-motor.

Level Gauges

Every steam boiler must have one or several direct and/or indirect level gauges.  Direct level gauges show the water level through a glass or mica shield. Indirect level gauges transfer the water level by using a float operated magnetic system to an indication ledge mounted outside of the pipe.

Sensors & Controllers

Electronic pressure-measuring station is used in heating and refrigeration systems, suitable for gases and liquids. A piezo resistive pressure sensor produces a pressure-proportional bridge voltage. This voltage is normalised to the corresponding measuring range and is given as a 4 – 20 mA signal.

Regulators (self-acting)

Temperature regulators in 2- and 3-way design.  Pressure reducing, excess pressure and differential pressure Regulating valves for controlling liquids, steam and gases.

Speciality Valves

Steam-converting valves reducing the steam pressure whilst simultaneously cooling the steam. The steam pressure is reduced by a low noise perforated cone. The water is injected into the perforated cone from below to atomise effectively and independent of load. These valves are designed to maintain constant pressure.

Pressure Vessels & Tank

The principle reason for the corrosion commonly found on mild steel boiler hot-wells and condensate pipework is the constant introduction of oxygen and carbon dioxide into the boiler feed-water. A properly designed pressurised de-aerator can bring the dissolved oxygen level to less than 0.02 ppm.

Bespoke Insulation Jackets

Removable and reusable high quality insulation jackets, CAD designed and manufactured for exact fit. Self-contained, so no direct exposure to insulation. For use in steam and process applications for thermal reduction, acoustic reduction, steam trap heat shields, sanitary wash down and fire blankets.

Our Core Values

Honesty, Reliability and Efficiency

Our Customers