Venturi pumps are commonly used for coolant mixers. The moving water across the coolant orifice creates a low pressure zone drawing coolant into the water stream. The combination of the two laminar flows creates a strong turbulent zone in which the two fluids are thoroughly mixed. Since there are no moving parts, the pump has a very high degree of reliability. The needle valve allows for a high degree of precision for setting the proportion of coolant mixed in with the water.