In many industrial applications, peristaltic pumps are used to pump different types of fluids. There are different types of peristaltic pumps used today, which include hose pumps, and tube pumps. The pumps are fitted with tube pumps rollers, which move along the extruded tubing. The rollers squeeze the tube as they move. The Duckbill is used with the high pressure pump models and serves as back flow prevention in the injection back check valve assembly. This protects the pump from excessive water pressure that leads to premature tube failure and backfilling of your tank. Specifications of Stenner Classic Series Pump Tubes: Models 45/85 Series, SVP, S Series. Stenner pump tubes come in 6 sizes and 5 packaging options.