Standard Models Have A One-Piece Brass Housing With Stainless Steel Spring, Pull Ring And Viton O-Ring Seal; Rugged Design Provides Trouble-Free Over Pressure Protection; All Brass And Stainless Steel External Construction; Compact, Low Profile Reduces Damage Risk; Weather-Resistant Viton O-Rings Withstand Decades Of Service; Stainless Steel Pull Ring Permits Safe Manual Bleeding Of Pressure; Meets Or Exceeds Industry Standards; 10 Psig Valves Comply With American National Standards (ANSI) C57.12.20.2007; Highly Flexible Designs For Many Applications; Compatible With Hole Fittings; Many Sizes Of Valves Allow For A Number Of Installation Options Including Retrofitting Older Equipment; Identification On Valve Makes Ordering, Installing Or Referencing Hassle-Free; Flow Rates Available From 35 To 200 Scsm; Designs Accommodate A Range Of Operating Pressures (3.5 Psi To 35 Psi); Design Prevents Entry Of Contaminants; Unique Configuration Inhibits Entry Of Contaminants; Covers Are Standard On Most Valves; Sunlight, Oil And Ozone Resistant Polypropylene Or Pvc Cap On Indicator Models