A control mechanism locks open a spring-loaded valve and automatically releases the spring-loaded valve to close upon a predetermined lesser weight load being applied. The spring-loaded valve includes a flow valve, a valve lever that pivots between open and closed positions, and a valve spring that biases the valve lever to the closed position. The control mechanism includes a pivotal release lever having an engagement arm and an opposite load arm, and a release spring that biases the release lever from a blocking position with the engagement arm retaining the valve lever in its open position to a release position with the valve lever free to pivot past the engagement arm and to the closed position under the valve spring force. The load arm includes an additive-container support for a load of an additive fluid to be mixed with a carrier fluid whose flow is controlled by the valve.

A control mechanism locks open a spring-loaded valve and automatically releases the spring-loaded valve to close upon a predetermined lesser weight load being applied. The spring-loaded valve includes a flow valve, a valve lever that pivots between open and closed positions, and a valve spring that biases the valve lever to the closed position. The control mechanism includes a pivotal release lever having an engagement arm and an opposite load arm, and a release spring that biases the release lever from a blocking position with the engagement arm retaining the valve lever in its open position to a release position with the valve lever free to pivot past the engagement arm and to the closed position under the valve spring force. The load arm includes an additive-container support for a load of an additive fluid to be mixed with a carrier fluid whose flow is controlled by the valve.

Disclosed herein is a positive pressure relief valve having a valve assembly, a trigger mechanism, an inlet manual override knob, and an outlet manual override knob. The valve assembly may comprises a valve throat and a main piston positioned at least partially within the valve throat, the main piston configured to selectively open and close the valve throat as a function of a pressure at the inlet to the valve assembly. The valve assembly may comprise a set of throat inserts within the valve throat. The trigger mechanism serves to quickly pressurize the main piston's diaphragm. The trigger mechanism may be positioned in a trigger mechanism housing at the outlet end of the valve assembly. The inlet and outlet manual override knob may be coupled to the main piston and configured to pull or push the main piston, thereby displacing the main piston to open the valve assembly.

Disclosed herein is a positive pressure relief valve having a valve assembly, a trigger mechanism, an inlet manual override knob, and an outlet manual override knob. The valve assembly may comprises a valve throat and a main piston positioned at least partially within the valve throat, the main piston configured to selectively open and close the valve throat as a function of a pressure at the inlet to the valve assembly. The valve assembly may comprise a set of throat inserts within the valve throat. The trigger mechanism serves to quickly pressurize the main piston's diaphragm. The trigger mechanism may be positioned in a trigger mechanism housing at the outlet end of the valve assembly. The inlet and outlet manual override knob may be coupled to the main piston and configured to pull or push the main piston, thereby displacing the main piston to open the valve assembly.

A nozzle opening and closing device for electrolyte injection comprises a nozzle having a discharge outlet for injecting an electrolyte into a battery assembly. The nozzle opening and closing device for electrolyte injection further comprises an opening and closing plate rotatably mounted on the nozzle, and provided to open or close the discharge outlet of the nozzle, and an opening and closing control part provided to control whether the opening and closing plate is opened or closed based on the weight of the electrolyte applied to the opening and closing plate.