Product Tag: rotary control valve

NAF – Duball DL Ball Valve

High-Performance Full-Bore Isolation and Control

The NAF-Duball DL is a full-bore, metal or soft-seated ball valve engineered for isolation, on/off and modulating control in demanding industrial services. Its split-body construction, spring-loaded stem packing, and bidirectional sealing deliver reliable shut-off and stable operation, even with difficult media and high differential pressures. A blowout-proof stem, rigid seat designs, and a robust torque path ensure consistent performance, while the off-centre body joint enables fast seat and ball replacement without removing the actuator. With direct mounting of the NAF-Turnex actuator and full integration with the NAF-D30 intelligent positioner, the Duball DL provides a compact, vibration-resistant valve package suitable for severe service across chemical, pulp & paper, mining, petrochemical and power applications.

For technicians, engineers and production managers, this means:

  • Reliable long-term sealing – Spring-loaded stem packing provides stable, maintenance-free operation in automated and control services.
  • Consistent shut-off under demanding process conditions – Floating ball design delivers bidirectional tightness, even with challenging media.
  • Reduced downtime during shutdowns – The off-centre body joint allows seat and ball replacement without removing the actuator, simplifying maintenance.
  • Stable torque transmission – Blowout-proof stem with long foot minimises backlash, ensuring predictable operation and accurate control.
  • Flexible trim and material options – Reinforced PTFE seats, Alloy 6 metal seats, sealed or scraper designs, and high-temperature variants address a wide range of duties.
  • Optimised for automation and control loops – Direct mounting of NAF-Turnex actuators and optional NAF-D30 positioners creates a compact, vibration-resistant valve package.
  • Improved process stability in high-energy applications – Optional Z-trim reduces cavitation and noise, protecting downstream equipment.

Our Valve Repair Centres in Secunda and Durban provide expert repair, reconditioning, automation and testing services, ensuring that your NAF-Duball DL valves remain in peak condition.

Robust design. Stable operation. Lower maintenance effort. 

Zwick – Tri-Con Triple Offset Valve

Engineered for absolute shut-off in the most demanding gas and liquid applications.

The Zwick Tri-Con triple offset valve is engineered for zero-leakage performance, even under extreme temperature variations and pressure peaks. With the widest laminated seal ring in the market, it provides unmatched durability and long-term sealing integrity, ensuring leak-free operation in critical gas and liquid services.

For technicians, engineers and production managers, this means:

  • Longer production runs, with fewer shutdowns
  • No costly or dangerous leaks, protecting the environment and process efficiency
  • Reduced seat wear, thanks to frictionless cone-in-cone sealing for smooth, low-torque operation
  • Lower installation costs—lighter weight and smaller installation envelope, reducing the need for large cranes, extended rigging crews, or costly modifications when replacing older gate valves

The frictionless triple offset seating design eliminates break-away torque, reducing actuator wear and enabling smooth operation—minimising maintenance and extending valve life.

With proven installations across synthetic fuels, oil & gas, chemical, and power generation industries in South Africa, the Tri-Con is available in double flanged, wafer, lug, butt weld and gate valve face-to-face configurations. It’s also ideal for oxygen service and steam-jacketed applications such as molten sulphur.

Our Valve Repair Centres in Secunda and Durban provide full valve reconditioning, automation, and testing services, keeping your Zwick Tri-Con in peak operating condition.

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