These Cartridge Insert Valves can be installed into tubing lines or glued into manifolds. The optional housing materials are Nylon, Polypropylene, Acrylic, Acetal, PVDF, and Polycarbonate. Springs are 316 Stainless Steel or Hastelloy® (1/2 psi). O-Rings are of Buna-N, EPDM, FKM, Silicone and Kalrez. Available sizes are 1/4″, 5/16", 3/8", 1/2″, 5/8" and 3/4" OD. Standard crack pressure for all valves except 3/4″ OD is 3" H₂O 0.1 psi, 5 psi, or 1.5 psi.