fig7 fig6 is a cross sectional view of system 10 illustrating the flow device 12 disposed within the mounting region 16 in the illustrated embodiment the brake assembly 70 comprises a lever arm 72 coupled to the housing 20 by a first pivot joint 74 and coupled to an engaging arm 78 by a second pivot joint 76 in certain embodiments the brake assembly 70 may be a single piece or multiple pieces additionally the brake assembly 70 comprises a spring mechanism 80 which interacts with an upper portion 82 of the lever arm 72 and with the housing 20 to bias the engaging arm 78 inwardly toward the blades 40 more specifically the spring mechanism 80 biases the lever arm 72 to rotate about the first pivot joint 74 in a counter clockwise direction however in the inserted configuration of fig6 the lip 60 counteracts the spring mechanism 80 to rotate the lever arm 72 clockwise out of engagement with the blades 40 upon removal the spring mechanism 80 rotates the lever arm 72 about the pivot joint 74 thereby forcing the engaging arm 78 to engage the blades 40 thus the brake assembly 70 stops rotation of the blades 40 during removal of the flow device 12 from the system 10 in other embodiments the spring mechanism 80 may be replaced by other means of providing resilient bias turning now to fig7 the flow device 12 is being removed from the mounting region 16 thereby engaging the brake assembly 70 against the blades 40 during removal of the flow device 12 the spring mechanism 80 expands against the upper portion 82 of the lever arm 72 to pivot the lever arm 72 counter clockwise about the.