ACO Q-Flap Valve is a wall-mounted non-return valve made from HDPE that allows water to discharge while stopping backflow. Gravity-operated flap opens with outgoing flow and closes automatically to prevent flooding. UV-stable for outdoor use and resistant to corrosion and chemicals. Available in HD and SD versions with sizes from DN100–2000mm. Designed for a 50-year service life.

  • Wall-mounted non-return valve for reliable one-way water flow at outfalls

  • Made from high-density polyethylene with stainless steel components (HD only)

  • UV-stable for long-term outdoor use

  • EPDM lip seal is easy to replace

  • Lightweight for easier handling and installation

  • Fast opening reduces silt and dirt build-up

  • Limited opening angle prevents the flap from sticking open

Applications

  • Outfall protection in drainage, wastewater, and coastal environments

Options and variations

HD version

  • DN100–2000mm

  • Permament meter water column: 1Mwc (above opening)

  • 72 hours meter water column: 5Mwc (from invert level)

  • Includes DN 400 stainless steel reinforcement 

  • Welded hinge construction

SD version

  • DN100–500mm

  • 72 hours meter water column: 1Mwc (above opening)

  • 5 hours meter water column: 5Mwc (from invert level)

  • Bolted construction

  • Faster install time - only four fixing points

Materials

  • High-density polyethylene (HDPE)

  • Stainless steel 316L (HD only)

  • EPDM lip seal

Performance

  • Designed for 50-year service life

  • Corrosion and chemical resistant

  • UV-stable

Installation

  • Wall-mounted above waterline

  • Lightweight for quicker, safer installation

  • SD version uses four fixing points

Maintenance

  • Minimal maintenance required

  • Serviceable EPDM lip seal