Althon design and manufacture high quality HDPE fish and eel friendly flap valves and fish friendly flap gates. Althon fish friendly flap valves are designed to prevent harm to fish as they migrate through flood and flow control equipment.

All of our fish friendly flap vales are manufactured in HDPE and SS316L with a design life of 50 years. Typically our flap valves are designed to max 5Mwc (72hrs) and 1Mwc (50 years) but we can tailor this to suit your specific requirements.

Althon fish friendly flap valves can be factory fitted to our precast concrete headwalls and chambers. For installation on site we supply with our fish friendly flap valves an EPDM seal, stainless steel fixings and chemical anchors.


If you require any assistance or more information please contact us by phone on 01603 488700 or by email