Flow control arrangements, semiconductor processing systems having flow control arrangements, and flow control methods

A flow control arrangement, comprising:

• a source conduit and a supply conduit;
• a shutoff valve connecting the source conduit to the supply conduit;
• a slow-close actuator connected to the shutoff valve to close the shutoff valve during a slow-close interval;
• and
• a pyrophoric material detector operably connected to the slow-close actuator and configured to close the shutoff valve upon detection of a metastable mass of a pyrophoric material disposed outside of the flow control arrangement,
• wherein the slow-close interval is sized to limit a shock communicated to the metastable mass by closing of the shutoff valve to prevent deflagration or detonation of the metastable mass;
• and
• a controller operably coupling the pyrophoric material detector to the slow-close actuator, the controller responsive to instructions recorded on a memory to:
• receive an indication of the metastable mass of the pyrophoric material is disposed outside of the flow control arrangement from the pyrophoric material detector;
• close the shutoff valve using the slow-close actuator during a slow-close interval that is between about 1 second and about 10 seconds, wherein an effective flow area of the shutoff valve is progressively reduced during the slow-close interval;
• and
• limit a shock communicated to the metastable mass of the pyrophoric material disposed outside the flow control arrangement and fluidly coupled to a fluid including the pyrophoric material traversing the shutoff valve by closing of the shutoff valve.