Stafsjö TV Knife Gate Valve Compact Isolation for Tank-Mounted Instrumentation

The Stafsjö TV knife gate valve is a specialized isolation solution designed for direct mounting on tanks, particularly where instrumentation such as transmitters or sensors require secure shut-off without draining the vessel. Engineered for compactness and reliability, the TV valve features a short face-to-face dimension and a unique flange drilling pattern, enabling direct installation at the tank outlet without the need for a counter-flange.

Its stainless steel construction—including the valve body (EN 1.4408), gate (EN 1.4404/AISI 316L), and retainer ring—ensures excellent corrosion resistance and durability in demanding environments. The valve is equipped with Stafsjö’s TwinPack™ gland box packing system, which provides a tight seal and prevents media leakage to the surrounding environment, even under cycling conditions.

The ratchet wrench actuator, supplied as standard, allows for quick and ergonomic operation, even in wall-mounted or hard-to-reach installations. The valve’s modular design supports a wide range of seat materials including EPDM, Nitrile, Viton, and PTFE with O-ring combinations, allowing customization based on media compatibility and temperature requirements (up to 280°C depending on seat and packing material).

Technical Highlights:

• Size: DN 80
• Pressure Ratings:
  • Body: 16 bar at 20°C
  • Differential: 3.5 bar at 20°C
• Leakage Class: EN 12266-1:2012 Rate A – zero visible leakage during testing
• Testing Standards: Pressure shell test at 1.5× max allowable pressure; seat tightness test at 1.1× differential pressure
• Flange Standards: EN 1092 PN10, ASME/ANSI B16.5 Class 150, MSS SP-81, TAPPI TIS 405-8
• ATEX Compliance: Optional design for Zone 2 and 22 (II cat 3 G/D)

Materials & Options:

• Valve Body: Stainless steel EN 1.4408
• Gate: Stainless steel EN 1.4404 / AISI 316L
• Seat Options:
  • EPDM (max 120°C)
  • Nitrile (max 100°C)
  • Viton (max 180°C)
  • PTFE with Nitrile or Viton O-rings (max 100–180°C)
• Packing Options:
  • TwinPack™ (max 260°C)
  • PTFE (max 280°C)

The TV valve is CE-marked and conforms to the European Pressure Equipment Directive (PED 97/23/EC), ensuring compliance with safety and performance standards. Its modular architecture allows for easy maintenance and adaptability, making it a cost-effective solution for tank-mounted isolation in industries such as pulp and paper, chemical processing, and water treatment.