This series of sight glasses are designed for attachment to an existing ANSI flanged nozzle or vessel studding outlet. Each is rated for 150 PSIG (10.3 Barg) at 300 ºF (149 ºC) with a tempered soda lime lens and 500 ºF (260 ºC) with a borosilicate lens and compatible gasket. Sight glasses are constructed using code materials. Optional accessories include Series PL, MSL, SLEX, REX, FBX illuminators, and Type I wipers. High pressure ratings and ANSI Class connections are available upon request. Note: Series NW-RF sight glasses are not supplied with fasteners unless explicitly stated otherwise.