The 10" Ames 4000CIV began in 1998 when the Ames Company was purchased by the Watts Regulator Company. The 4000CIV was actually a retagged Watts 909. The body was constructed of epoxy coated cast iron. Check assemblies were made of bronze and stainless steel. Check seats are replaceable and of bronze construction. The relief valve seat is replaceable and made of stainless steel. The relief valve uses an external sensing line. No special tools are required to service.