The Chloritrol valveless metering system from Fluid Metering allows for accurate, maintenance-free injection of liquid sodium and calcium hypochlorite for treatment of municipal drinking water. The valveless duplex pump design first injects liquid hypochlorite directly into the water main. The secondary pump removes out-gas bubbles from the system, preventing loss of prime. It will self-prime against pressures up to 125 psi. Internal components are made of sapphire-hard ceramics that provide long-term, drift-free accuracy. Flow rate is controlled by a Model V300 variable-flow controller that accepts 4-20 mA, 0-5 VDC and 0-10 VDC signals from process sensors and instrumentation. Flow rate can be manually controlled using convenient front panel membrane switches and an LED readout. 800/223-3388; www.chloritrol.com.