Syringe pumping system with valves

A pumping system for medical fluids with a hypodermic syringe means connected to inlet and outlet check valves, wherein the improvement comprises:

• a valved body with an inlet passage from which pumped fluid is supplied, a syringe connecting passage, and an outlet passage, said passages being in fluid flow communication within said valved body;
• an inlet valve seat in the inlet passage facing downstream of inlet fluid flow;
• an outlet valve seat in the outlet passage facing downstream of outlet fluid flow;
• a flexible imperforate disk valve member fitted against each of the inlet and outlet valve seats;
• a pair of upstream facing posts internal of the valve body and connected to the valve body for respectively urging each disk valve member against its respective valve seat;
• one of said posts biasing its valve member so as to require a substantially greater opening pressure in the range equivalent to a water head of 10 to 100 inches, while the other post is positioned to require the other disk valve to open at a pressure in the range equivalent to a water head of 0.1 to 10 inches;
• and a flexible conduit connected to the inlet passage and which conduit is adapted to attach to a medical liquid source, whereby fluid can flow from a fluid supply source through the inlet passage into the syringe on an intake stroke of the syringe and be pumped out through the outlet passage while fluid flow out through the inlet passage is blocked.