D. K. Instruments pvt. Ltd. An iso 9001:2000 certified company manufactures a wide range of level, flow and pressure instruments. As a part of that the model sf100 is a flanged/screwed sight flow indicator with a cast/fabricated body. This sight flow indicator provides visual observation and monitoring of the process flow stream. Available devices to enhance visibility include, flapper and rotator. Bodies are available in bronze, iron, steel and stainless steel. Special alloys are also available. Standard units are available in 150#, 300# and 600# ansi ratings.