Unique Valve Seat Designs
Soft Seat Design
Flowseal is one of the world's leading manufacturers of high performance butterfly valves. Based on many years of research, development, and field experience, the Flowseal design is superior to, and more versatile than, the High Performance Butterfly Valve design offered by other manufacturers.
The Flowseal soft seat valve provides a bi-directional bubble tight shutoff (zero leakage) by the use of a patented seat. This unique seat design creates a self-energized seal in vacuum-to-low pressure applications. Under higher pressure conditions, the seat is also designed to permit, confine, and direct movement of the soft seat against the disc edge, up to the full ASME Class 150, 300 and 600 Cold Working Pressures.
The soft seat is designed for high services with minimal wear and low torque. Seat replacement is a simple operation, requiring no special tools.
Metal Seat Design
The Flowseal metal-to-metal seat high performance butterfly valve incorporates an Inconel® seat for higher tensile strength, a 300 series stainless steel back-up ring in the seat cavity for axial seat support, and a disc that is case hardened by nitriding.
The Inconel® seat, by its dynamic and flexible design, applies enough force per linear inch against the disc edge (Rockwell Hardness of C66 to C70) to obtain an optimum sealing characteristic while controlling the loads between the metal surfaces.
The Flowseal metal-to-metal seat valve is utilized for temperatures up to 900°F (482°C) in compliance with ASME B16.34 pressure/temperature specifications. Leakage is rated at Class IV per ASME FCI 70-2.
Inconel® is a registered trademark of Special Metals Corporation.
Fire Flow Design
The Flowseal Fire-Flow™ high performance butterfly valve (HPBV) is a fire-safe, soft seat quarter-turn valve. The Fire- Flow™ design incorporates two patented seats which function together to seal off pipeline flow. In normal operation, the soft seat provides a bi-directional "bubble tight" shutoff (zero leakage); the metal seat provides bi-directional shutoff in the event of a fire, in conformance to industry fire-safe requirements.
With little or no pressure, the Fire-Flow seat creates a selfenergized seal against the disc. Higher line pressures act on the geometry of both seats to dynamically load them against the disc, creating higher sealing forces in either direction.
The Fire-Flow™ metal seat is made of Inconel® material which is shaped by a proprietary hydroforming process into its unique, patented design. Stainless steel outer bearings are included for post-fire disc and shaft alignment. Fireproof packing is used to prevent external shaft leakage.