Typically used in high pressure applications where there is a risk of exceeding the maximum force specified or the pump runs past the end of the syringe. Without the optical encoder, the pump will continue to cog in the event of a stall. Not to be used as a normal means of stopping the pump. Long Chassis Option. Pre-owned Graseby 3150 Syringe Driver. The Graseby 3150 syringe pump, from Smiths Medical, features precision components and patented design to ensure high accuracy within infusion. Product Features: Continuous, Preset Volume and Intermittent Infusion Modes. Manual (hands-on) Bolus. Volume (ml/hr) and Mass Units Infusion Programming.