Control valves

In complex industrial systems, the ability to regulate fluid flow with accuracy and reliability is critical for ensuring process efficiency, equipment safety, and energy optimization. Control valves serve this essential role by modulating flow rates, pressures, and temperatures in real time, maintaining system balance even under changing load conditions. 

ZETKAMA’s control valves are engineered to deliver high-performance regulation in such environments, offering durable construction, configurable actuation, and compatibility with a broad range of operating conditions. Whether integrated into heating networks, steam systems, shipboard installations, or industrial water loops, these valves are a dependable choice for continuous, responsive process control.

Design and Construction

ZETKAMA control valves are bellows-sealed valves equipped with a pneumatic actuator and a positioner (zCON). These valves are designed for modulating flow and are available in various material configurations to suit specific operating conditions.

• Body materials:
  • Grey cast iron (EN-GJL-250)
  • Nodular cast iron (EN-GJS-400-18-LT)
  • Cast steel (GP240GH+N, 1.0619)
  • Cast stainless steel (G-X5CrNiMo19-11-2, 1.4408)
• Nominal diameters: DN15 to DN150
• Pressure classes: PN16, PN25, PN40
• Temperature range: –10°C to +400°C (depending on the material)
• Face-to-face dimensions: acc. to EN 558, Series 1
• Flange drilling:
  • EN 1092-2 for cast iron bodies
  • EN 1092-1 for steel and stainless-steel bodies

Internal components such as the disc, stem, and seat ring are made of stainless or alloyed steel, including materials like X20Cr13, 1.4021, and X6CrNiMoTi17-12-2, providing mechanical durability and chemical resistance. The valve uses a welded metal bellows made of X6CrNiMoTi17-12-2 for enhanced sealing performance.

Actuation and Control Options

The valves are fitted with pneumatic actuators available in two configurations:

• SPZ (Spring-Closed) – normally closed actuator
• SPO (Spring-Open) – normally open actuator

Both types can be combined with the following positioners:

• SRI 986 – electro-pneumatic positioner
• SRD 998 – intelligent digital positioner

ZETKAMA control valves are actuated pneumatically and can be configured in one of two standard operational modes. The SPZ version (Spring-Closed) functions as a normally closed valve, where the actuator opens the valve under supply pressure and returns it to a closed position via spring force once the signal is lost. Conversely, the SPO version (Spring-Open) is normally open, and it closes under pressure and reopens when the supply is cut off. This design allows for fail-safe positioning tailored to the requirements of the specific installation.

To enhance control precision and responsiveness, both actuator types can be equipped with advanced positioners. The SRI 986 electro-pneumatic positioner allows for proportional valve control based on analog input signals, while the SRD 998 digital positioner offers intelligent features, including diagnostics and remote calibration. The actuator system operates under a maximum supply pressure of 4.0 bar and is engineered to support an equal percentage flow characteristic, enabling stable regulation even with significant changes in differential pressure. Closing force and valve sealing performance vary depending on actuator type, size, and air supply — all parameters are defined in the technical specification sheets, ensuring appropriate selection for each application.

Tested Performance and Certification

All ZETKAMA control valves undergo rigorous factory testing to verify their compliance with European quality and safety standards. The valves are qualified for leakproofness class IV according to EN 60534-4, confirming their suitability for applications requiring high operational tightness and low permissible leakage rates. Functional and pressure tests are performed in accordance with EN 12266-1, ensuring reliability under the declared pressure and temperature limits.

Additionally, the product line is CE-marked for nominal sizes DN ≥ 32, conforming to the Pressure Equipment Directive 2014/68/EU, which governs the design and manufacture of pressure-retaining components in the European Union. The control valves are offered with fully documented pressure-temperature diagrams based on the material and nominal pressure class, in compliance with EN standards. This ensures that every valve operates safely within the declared mechanical and thermal limits.

Application Scope

ZETKAMA control valves are suitable for a wide range of fluids typically encountered in industrial environments. Depending on the specific material configuration of the valve body and internal components, these valves can regulate glycol, industrial water, diathermic oil, steam, compressed air, and other neutral process media. The compatibility of each valve with the working fluid depends on critical factors such as chemical resistance of the construction materials, system pressure, and operating temperature.

Thanks to their mechanical robustness, thermal resilience, and modular actuation options, these valves are used in various sectors including shipbuilding, heating installations, and refrigeration and air conditioning systems. Each application must be verified against technical documentation to ensure correct material selection and functional performance under the intended operating conditions.

Reliable Flow Control Backed by Engineering Expertise

With their high structural integrity, precise actuation mechanisms, and proven compliance with international standards, ZETKAMA control valves offer an optimal solution for regulating fluid flow in critical industrial systems. The Fig. 236 model demonstrates how intelligent mechanical design, supported by robust pneumatic control and advanced positioners, can ensure process stability even under variable loads and demanding thermal conditions.

Each valve is manufactured with attention to detail, tested under controlled conditions, and supplied with comprehensive technical documentation — providing engineers and system integrators with confidence in performance, durability, and regulatory conformity. When reliability and control matter most, ZETKAMA control valves are a trusted component in complex process environments.