2. Shutters and dampers

2.1 General provisions

1 – The entire control system must be located outside the duct, with the exception of thermal tripping devices.

2 – It must be durably treated against corrosion, taking into account the environment in which it will be installed.

3 – Pivoting and sliding axes must be designed to allow the device to operate without lubrication. The driving force or torque must be at least ten times the resultant of the resisting forces or torques due to friction.

4 – If applicable, the device must include :

• can be locked in the safety position;

• end-of-stroke cushioning.

5 – Any contactors used...