Abstract: A fluid flow indicator consists of a flow chamber having a freely spinning flow rate indictor that rotates in response to fluid flow and rotates in proportion to the rate of flow. A visible indicator allows a medical practitioner to carefully control the flow rate even though the fluid flow is smooth without other visible signs of movement. In one embodiment a plurality of flow holes are provided in the fluid chamber to direct the fluid around the fluid flow indicator rotor causing the rotor to rotate in proportion to the rate of fluid flow. Another embodiment provides a flow opening to direct the fluid past the rotor. The fluid chamber is provided with a connecting nipple on either end to connect the flow indicator with a fluid delivery system.

Abstract: A safety radiator cap has a centrally located pressure plunger that forces pins outward against the inside of a radiator fill tube to prevent opening of the cap when the system is under pressure. As the liquid cools, the pressure is reduced and the pins retract due to biasing springs which allow the cap to be removed thus ensuring that the cap can only be removed when safe. Pressure pads at the end of the pins allow an embodiment of the invention to be used in any vehicle without retrofitting.