UltraFlow 390-393 Series

Ultraflo proudly offers the 390/393 Series butterfly valve – designed specifically for pneumatic conveying and abrasive applications. The valve characteristics include a seat designed specifically for schedule 40 piping, matching the seat ID with the inside diameter of the pipe wall. The result is smoother product flow and less abrasion of valve components. Valve sizes range from 2” – 12”.

The 390/393 Series provides a bidirectional pressure rating of 150 psi with stainless steel disc/stems and 100 psi with encapsulated disc/stems. Undercut disc/stems, rated for 50 psi and requiring less operating torque, are also available. Valves installed in dead end service (downstream flange removed) are derated to 75 psi. Figure 390 valves are Wafer style bodies offered in Stainless Steel, Cast Iron and Aluminum. Figure 393 valves are Lug style bodies offered in Stainless Steel and Nodular Iron.

Ultraflo’s resilient Seat (A) is the heart of all 300 Series valves. The seat incorporates a dovetail retention system ensuring positive alignment and ease of assembly. All 300 Series seats include an integral flange seal molded into the seat face providing a positive seal with all popular flanges. In addition, an O-ring is molded into the stem hole of each 300 Series elastomer seat to provide an added level of protection.


Features Primary and Secondary Seals (B) The primary seal is formed by an interference fit between the disc hub and the seat flat. The secondary seal is an interference fit between the stem and seat stem hole. The secondary seal also incorporates a molded O-ring in the stem hole of each elastomer seat providing increased interference and an added level of protection. These seals prevent line media from coming into contact with other valve components. Ultraflo’s ultrathin one-piece Disc/Stem (C) provides a high flow capacity with smooth flow characteristics that greatly reduce line media pressure drops. The disc edge is CNC machined and hand polished to produce bubble tight shut off, minimum torque and longer seat life. The Upper Stem Bushing (D) absorbs operator side thrusts, provides precision alignment to ensure less wear and lowers operating torque. The Lower Stem Bushing (E) eliminates gaulding and frozen stems. Both upper and lower bushings are heavy duty non-corrosive thermoplastic polymer. A Stem Packing (F) prevents external contaminants from entering the stem bore.

The Split Body (G) design simplifies field maintenance by eliminating the need for special tools or presses during installation of replacement seats. All 300 Series valve bodies are designed to fit between ASME/ANSI 125 or 150 lb. flanges. Body Recesses (H) accommodate lightweight flanges. Body Bolt (I) materials are zinc plated carbon steel or stainless steel as standard.


  • Size Range: 2″ – 12″ (50mm – 300mm)
  • Body Style: Wafer, Lug
  • Temperature Range: -40°F to 400°F (-29°C to 204°C)
  • Pressure Ratings: Bidirectional: 150 psi – 50 psi
  • Body Materials: Cast Iron, Nodular Iron and Investment Cast 316 Stainless Steel. Aluminum bodies available in wafer only.
  • Disc Materials: 17-4 Stainless Steel and Investment Cast 316 Stainless Steel. Elastomer encapsulated and custom disc coatings available.
  • Seat Materials: Nitrile, White Nitrile, EPDM, Buna, FKM, PTFE (select sizes)
  • Applications: Pneumatic Conveying & Abrasive