Inexpensive yet rugged construction in a welded chamber control. The 291
series is specifically designed for single stage operation where
pressure does not exceed 350 psig (24 bar) at 100°F (38°C) or 300 psig
(21 bar) at 600°F (315°C) available with a
variety of hermetically sealed snap switch or mercury switch circuits
protected by a general purpose, weatherproof or explosion-proof
enclosure and will accommodate specific gravities down to 0.60.