Components 1 Body Cast iron or ductile iron 2 Disc Cast iron or ductile iron 3 Stem Stainless 4 Bonnet Cast iron or Ductile iron 5 Bonnet Nut Brass or Gunmetal 6 Operatve Cap Cast iron or ductile iron Application 1 Flange end BS4504 PN16 2 Nominal Pressure PN16 Test Working Pressure PN16 Test Pressure Shell 24bars Seat 17.6bars