Excess flow shutoff valve

An excess flow shutoff valve comprising:

• a valve body defining an internal volume and having an inlet port and an outlet port;
• a valve plug having an upstream end and a downstream end, the valve plug movable within the valve body from a position that permits fluid to flow from the inlet port to the outlet port to a position that blocks fluid from flowing from the inlet port to the outlet port, the valve plug movable from the position that permits fluid to flow from the inlet port to the outlet port to the position that blocks fluid from flowing from the inlet port to the outlet port upon activation of an activation component;
• a partition disposed within the valve body, the partition forming a first chamber and a second chamber within the internal volume of the valve body, wherein the valve plug is disposed within the second chamber when the valve plug is in the position that permits fluid to flow from the inlet port to the outlet port;
• and
• the activation component disposed within the valve body and operatively connected to the valve plug to hold the valve plug in place within the second chamber in the position that permits fluid to flow from the inlet port to the outlet port;
• wherein at least one of the valve body and the partition define one or more orifices for fluid flow from the first chamber to the second chamber when the valve plug is in the position that permits fluid to flow from the inlet port to the outlet port, the one or more orifices at a position downstream of the downstream end of the valve plug when the valve plug is in the position that permits fluid to flow from the inlet port to the outlet port wherein the one or more orifices create a pressure difference between the upstream end of the valve plug and the downstream end of the valve plug when fluid flows through the valve body, wherein the pressure difference is less than a target pressure difference for activating the activation component when the fluid flows through the valve body at a lower rate, which is less than a target flow rate, and the pressure difference exceeds the target pressure difference for activating the activation component when the fluid flows through the valve body at a higher rate, which is greater than the target flow rate;
• wherein the activation component comprises a pin, the pin loaded in bending, the pin having a strength such that the pin will break upon the pressure difference exceeding the target pressure difference occurring between the upstream end of the valve plug and the downstream end of the valve plug, wherein the pin holds the valve plug in place within the valve body when the valve plug is in the position that permits fluid to flow from the inlet port to the outlet port, wherein upon the pin breaking, the valve plug is caused to move to the position that blocks fluid from flowing from the inlet port to the outlet port.