Model 1800 in-line flow switch features all-plastic components made of PVC, an O-ring of Viton "A," and a return spring of 316 stainless steel. Process connections are standard with 1-inch slip ports and optional adapters available in 3/4 and 1/2 inch slip as well as 3/4 and 1/2 inch NPT. The unit operates by a positive displacement principle. A shuttle housing a magnet is displaced by the liquid's flow or no flow to actuate a hermetically sealed reed switch encapsulated within the stem.
Thomas Products Ltd., Flow Switch Div., 987 West St., Southington, CT 06489, FAX (860) 621-1470.