Abstract: An adjustable automatic recirculation valve includes a valve body, a main valve disk, a bypass valve and a dynamic adjustment assembly. The main valve disk is positioned within the valve body and opens in response to fluid flow between a main inlet and a main outlet. The bypass valve controls the flow of fluid between the main inlet and the recirculating outlet. A dynamic adjustment assembly, housed within the valve body controls the operating lift associated with the maximum opening of the bypass valve to regulate fluid flow capacity to the recirculating outlet.

Abstract: A check valve with an elongated body and a hole extending from an inlet end to an outlet end. A piston assembly is mounted within the body and can include a piston, a check valve seal and a piston spring. The piston spring biases the piston to a first piston location preventing air from flowing from the inlet toward the outlet end. The check valve seal can be positioned on the piston assembly to seal against either a check valve seat or the inside diameter of the hole to restrict air flow when the piston is in the first piston location. Movement of the piston to a downstream piston location can remove the check valve seal from the check valve seat and/or from the inside diameter of the hole, allowing air to flow from the inlet end toward to outlet end.

Abstract: A check valve with an elongated body and a hole extending from an inlet end to an outlet end. A piston assembly is mounted within the body and can include a piston, a check valve seal and a piston spring. The piston spring biases the piston to a first piston location preventing air from flowing from the inlet toward the outlet end. The check valve seal can be positioned on the piston assembly to seal against either a check valve seat or the inside diameter of the hole to restrict air flow when the piston is in the first piston location. Movement of the piston to a downstream piston location can remove the check valve seal from the check valve seat and/or from the inside diameter of the hole, allowing air to flow from the inlet end toward to outlet end.

Abstract: A device for over-pressure protection of a tank has a main body defining a main passage with an inlet and an outlet. The main body also defines a release passage branched from the main passage. A shut-off mechanism is movably disposed within the main passage and defines an open position for allowing a liquid to flow from the inlet to the outlet and a closed position for at least partially blocking the flow. Additionally, a plunger is movably disposed within the main body and connects to the shut-off mechanism. The plunger has a weight sufficient to maintain the shut-off mechanism in the open position until pressure in the release passage exceeds a predetermined value.