Zetrix unites all the benefits of a metallic sealing process valve with the advantages of a butterfly design. With its small footprint and reduced weight, this cutting-edge butterfly valve is very easy to handle. The triple offset principle guarantees a permanently tight seal conforming to leakage rate A as per DIN EN 12266-1, because the valve fits precisely and closes without friction. Available in cast or stainless steel, it can optionally be used as an isolation and control valve – yet another example of its great versatility.
Zetrix is suitable for liquids, gases and vapours in a wide range of applications, for example in oil and gas processing, refineries, petrochemicals, chemicals, solar thermal power stations, power plants, district heating, pulp and paper, steelworks, sugar processing and industrial and plant manufacturing in general.
The Zetrix design was developed and optimised using the very latest generation of tools, including the finite element method, contact angle calculations, flow simulations and characteristic measurements. Field tests (e.g. fire safe) and endurance trials were carried out at an accredited testing laboratory as well as in our own experimental lab. The new Zetrix process valve has been tested and approved as fire safe according to ISO 15848 / German clean air regulations (TA-Luft) and SIL. The finite element method (FEM) is a numerical calculation technique that was used to simulate the stresses and their distribution occurring over the valve disc. The aim was to achieve the required strength at pressure load levels in combination with a slim and flow friendly shape.
The media flow through the piping system was additionally determined with the help of flow simulations which enabled the flow velocity, flow direction and pressure distribution to be visualised. Due to the optimised disc geometry, turbulences have been minimised and pressure loss prevented. The result: uniform flow plus a high flow capacity. The flow values in different valve positions were measured on a special test section in our in-house laboratory. The curves obtained in this way were used to fine-tune the control characteristic of the process valve.
The rotation of the lamellar sealing ring into the body seat was optimised by ensuring that all sealing geometry parameters are precisely coordinated. The ideal plug shape that is critical for frictionless opening and closing of the Zetrix valve was then computed. Last but not least, the new valve was subjected to the acid test. In many applications there is an increased fire hazard. In the event of a fire, the valve must continue to meet internal and external leak-tightness requirements for a defined period of time if exposed to direct flame impingement. This ability was impressively demonstrated in a fire safe test according to ISO 10497 / API 607 6th Edition.
All the key features at a glance:

• The metallic sealing Zetrix has a triple offset design; in addition to a “smart”, self-aligning sealing ring, it also provides isolating and control functions. It is tight closing according to DIN EN 12266 (leakage rate A), has a stellited seat, hardened shaft bearings and a blow-out proof stem as standard and can be used as a pipe-end valve on both sides. The valve can be insulated in line with industrial standards and has ISO 15848 / TA-Luft, ISO 10497 / API 607 6th Edition fire safe and SIL approvals.
• The Zetrix design complies with DIN, ANSI and API specifications, and the valve can be made from either cast carbon steel (1.0619 +N; SA216WCB) or stainless steel (1.4408; SA351CF8M). Its face-to-face length corresponds to DIN EN 558-1 Series 13 (double flanged), Series 16 (fully lugged) or Series 14 (new version with butt weld ends). The valve is rated for operation at temperatures from -29°C to +427°C. Zetrix process valves are available in several different nominal diameters from DN 80 to DN 1200, for nominal pressures from PN 10 to PN 40 and conforming to Class 150 or Class 300, depending on the type of connection. Apart from the double flanged design, the valves can also be ordered as a fully lugged version or – in future – with butt weld ends. Zetrix valves are used with a manual gearbox or with a pneumatic, electric or hydraulic actuator. The manufacturer emphasises that other configurations, e.g. customer-specified connection types, nominal diameters, pressure classes, face-to-face lengths, materials and temperature ranges can also be implemented on request.
• The above-mentioned product series is further enhanced with an array of useful options: a flushing port for the shaft bearings and a buffer port for protecting the stuffing box, a flushing port for the bottom flange, a welded bottom flange, a double packing with a drainage line (e.g. for thermal oil services), a test port, a “clean air” bushing according to TA-Luft, a solid sealing ring for special applications, a heating jacket for high viscosity fluids and blow-out protection to API 609.
• Zetrix is typically used in the oil and gas industry, chemicals and petrochemicals, district heating, energy and power plants, iron and steel, food and beverages, sugar making, shipbuilding, the gas sector and pulp and paper.