Triple Offset Valve Technology

Vanessa's seating force is generated by externally applied torque rather than by mechanical interference as in position-seated ball, butterfly and plug valves. This means that the cone-to-cone sealing occurs by contact pressure and not by friction generated by the elastic deformation of the seat. This feature allows our valve to handle high pressure classes and provide reliable and highly controlled operating torque. Our trim design, seating angles and surface finish all contribute to a very low, consistent and predictable torque demand which is unaffected by fluid temperatures and pressures throughout the valve life. The non-rubbing rotation ensures low and constant running torque across the 90 degree rotation so that the operating torque calculated and tested on a newly manufactured product is equal to a comparable fully operational valve.

Metal-to-metal sealing ultimately ensures that the valve can handle virtually all possible temperatures, pressure levels and fluid types. We use a Stellite® grade 21 seat and a resilient seal ring in Duplex as a minimum with high mechanical resistance. Stellite® 21 is a cobalt alloy that coats the body seat to provide hardness, resistance to fluid abrasion, corrosion and general wear. Due to its unique design, the metal seal ring has elastic properties which allow for radial compression to be uniformly distributed around the seating surface. These are key contributors to the zero leakage performance of the valve.

Stellite® is a registered trade name of Deloro

A quarter turn rotation means significantly lower and more consistent running torque compared to any rising stem design, ensuring that Vanessa TOVs can achieve extremely quick stroke times. This also eliminates any negative effects on packing caused by rising stems, such as extrusion and abrasion, and ultimately provides for a more compact valve design.

Eliminating contact between seat and seal during opening-closing means extending the life of the sealing elements and the valve altogether. This also combines with the main feature of quarter turn rotation, i.e. low and consistent running torque, for which valve operation remains quick and easy over time and modulating is possible even at extremely low angles. The ability of handling quick stroke time requirements and a high number of cycles is also correlated to the valve non-rubbing feature. Users can ultimately reap the critical benefit of longer lifecycle of the sealing elements compared to other valve designs.

Our cryogenic configuration has been designed in order to operate with temperatures down to -254 °C (-425.2 °F). The following features differentiate Vanessa Cryogenic Series 30,000 from the basic configuration:

• Vanessa seal ring is always a one-piece solid in Nitronic^® 50 (Solid Seal Ring) - a material highly resistant to corrosion able to preserve important mechanical features at low temperatures. Nitronic^® 50 also has exceptional yield strength, approximately double that of other series 300 stainless steels at ambient temperature.
• An extended bonnet keeps packing protected from cryogenic service temperatures down to -254 °C (-425.2 °F), meeting the requirements of BS6364 for non-cold box applications and major end user specifications.
• Cryogenic valves are available in Double flanged, lug, buttweld and buttweld top entry body styles:
  • Double flanged body
    The most widely used pipe connection - it enables the best gasket load distribution and short bolting reduces the risk of stretching. The standardized flange design also ensures safe pipe jointing and ease of assembly/disassembly from the line. Vanessa provides ASME and EN flanges including designs to ASME VIII sect 2 div.1.
  • Buttweld body
    The ideal choice whenever flanged connections need to be reduced, this design provides significant initial cost savings. The buttweld body completely eliminates the possibility of fugitive emissions through flanged joints induced by the adjacent pipe stresses. As for all Vanessa valves, ongoing maintenance is not required.
  • Lug body
    A single flange design and more economical than Double flanged, as it requires less material. With threaded inserts on both sides, it is installed using two sets of bolts and no nuts. According to common industry practices, operators tend to avoid using this body style for diameters higher than NPS 36 due to operational difficulties in installing the valve.
  • Buttwed top entry body
    When an inline maintenance capability is mandatory, this design allows for access without removing the valve body from the line. The entire valve trim can be removed from the body and individual valve parts can be accessed in total safety. This feature allows for any unpredictable and extraordinary valve repair, which would be impossible, impractical or unsafe with different valve designs. Overall, the maintenance of a Vanessa valve remains largely unnecessary throughout the product lifecycle.

Nitronic^® is a registered trade name of AK Steel

Our high temperature configuration has been designed to operate with temperatures up to 815 °C (1,500 °F). The following features differentiate Vanessa High Temperature Series 30,000 from the basic configuration:

• Vanessa seal ring is always a one-piece solid in different materials depending on the valve body - this ensures no graphite oxidation and weakening, while allowing for various hard facing technologies to be applied in order to respond to application risks.
• A bolted extended bonnet keeps packing protected from high service temperatures up to 815 °C (1,500 °F).
• Bearings and thrust bearing can be hard faced with Stellite® or other overlays ensuring high mechanical properties and responding to application risks.
• All materials, including disc bolting, are selected to guarantee suitable mechanical properties in high temperatures and consistent thermal expansion rates.

Stellite^® is a registered trade name of Deloro