Flow control arrangements with flow switches, semiconductor processing systems, and flow control methods

A flow control method, comprising:

• at a flow control arrangement including a housing seating an inlet conduit and an outlet conduit, an isolation valve arranged within the housing and fluidly coupled to the inlet conduit, a first flow switch with a first shutoff trigger arranged within the housing and fluidly coupling the isolation valve to the outlet conduit, a second flow switch with a second shutoff trigger arranged outside of the housing and fluidly separated from the first flow switch, and a controller operably connecting the first flow switch and the second flow switch to the isolation valve,
• receiving a first fluid including a hazardous material at the first flow switch;
• receiving a second fluid including an inert/diluent fluid at the second flow switch;
• acquiring a first fluid flow rate with the first flow switch and a second fluid flow rate with the second flow switch;
• comparing the first fluid flow rate to the first shutoff trigger and the second fluid flow rate to the second shutoff trigger;
• closing the isolation valve using the controller when the first fluid flow rate of the first fluid traversing the first flow switch is greater than the first shutoff trigger;
• and
• closing the isolation valve using the controller when the second fluid flow rate of the second fluid traversing the second flow switch is less than the second shutoff trigger.