Non-return low flow flap valve - has counterweight and spiral return spring biassing flap towards seat

摘要

The valve is housed in a split box section fitted into the pipeline between e.g a solar panel (C) and a hot water storage tank (R). The valve has a hinged flap (3) with a counterweight (3a). The assembly also incorporates a spiral return spring (6) tending to close the flap onto the seat (5). The flap and counterweight are housed in one section of the split box with the return spring housed in the other with its free end located in one of the locations (7a,7b,7c) in the intermediate plate, according to the pre-tension required.