Donald, The Caleffi 636600A will work in piping up to 8". Your 3" pipe installation is shown up to 208 GPM at a 1 PSID. Please refer to the hydraulic characteristics chart in the Technical Brochure. Also it is important to have the unit installed in a cast TEE to make sure the paddle has full travel from open to close. That is shown in the technical brochure as well.
Donald, The Caleffi 636600A will work in piping up to 8". Your 3" pipe installation is shown up to 208 GPM at a 1 PSID. Please refer to the hydraulic characteristics chart in the Technical Brochure. Also it is important to have the unit installed in a cast TEE to make sure the paddle has full travel from open to close. That is shown in the technical brochure as well.