Varea-Meter® Variable Area Flow Meters - UGSI Chemical Feed, Inc. manufactures a broad line of flow meters for readout, transmission and control of fluid rate for most industrial process applications. For low-capacity, low pressure applications we offer glass tube purge meters with stainless steel frames. Purge meters are specifically designed for purging instrument cases and control lines, and are readily adapted to liquid-level indication, sampling, liquid specific gravity determination and similar applications. For low flow, higher pressure applications armored purge meters are available. For high volume flows glass-tube and metal tube meters are available in a variety of sizes and configurations for metering both air and liquid.