Apollo/Conbraco 40-100 Series Double Check Valve Assembly: Domestic Bronze Body; Top Access Checks & Test Cocks; Replaceable Seats & Reversible Silicone Seat Discs. 3/4 - 2" In production from 1989-2012. Two body styles were produced, wye pattern and top entry. Wye patterns were discontinued in 2002. A seat removal tool is required to replace seats. The check seats are not contained and the covers have spring pressure against them. Use caution when servicing.