BS EN 17088:2021 pdf free download – Side curtain ventilation systems一Safety.
For correct operation of side curtains, the manufacturer shall state the maximum wind speed (within the operating instructions, 5.9.4) where the system can be operated without risk of failure of the system.
The deflection of the curtain or other elements resulting from the differential pressure specified shall not cause permanent deformations which will affect the functioning of the system or create any risk of jamming.
5.2.4 Steel wire ropes, synthetic ropes, and straps
5.2.4.1 General
Steel wire ropes, synthetic ropes, and straps, etc. shall be suitable for the intended application with regards to strength, durability and corrosion resistance.
For suspension elements, a single wire rope, synthetic rope, or strap, etc. can only be used if a failure of the element will result in the curtain falling under gravity in a safe manner, i.e. the falling curtain will be restrained in a controlled manner that would not expose people near to it to increased risk of crushing, shearing, entanglement, drawing-in or trapping.
Where two or more suspension elements are used, it shall be ensured that the dead loads are shared in a pre-determined way.
The guaranteed minimum breaking strength of such a suspension element determined by calculations of the maximum load it has to support, multiplied by the safety factor (Table 1).
All such suspension elements shall have terminations and/or joints with a breaking load of no less than
90 % of that of the element, or a suspension element safety factor design working load. Terminations on
a drum shall always have a minimum of two full turns left on a drum in the terminal position. Measures
shall be taken to ensure that terminations cannot be accidentally detached.
Where such suspension elements enter grooves on drums or pulleys, the design shall ensure that the elements are aligned correctly to allow entry of the suspension elements.
Suspension element drums mounted up to a height of 2,7 m above floor level or another permanent level shall be fitted with a guard.
5.2.4.2 Steel wire ropes
For steel wire ropes, where failure of the rope would result in increased levels of risk to crushing, shearing, entanglement, drawing-in or trapping:
— each steel wire rope shall have a safety factor of no less than 6 (minimum breaking strength/static load);
— rope pulleys and rope drums shall have a pitch circle diameter (P.C.D.) at least equal to 20 times the rope diameter;
— rope drums shall be grooved, and the ropes coiled in only one layer;
— rope pulleys shall be designed so that the steel wire rope cannot jump out of the pulley.
Steel wire ropes used commonly in systems typically will not result in increased levels of risk, i.e. if the curtain falls down in safe manner (e.g. within the wind bracing). For steel wire ropes where failure of the rope would not result in increased levels of risk:
— each steel wire rope shall have a safety factor of no less than 3 (minimum breaking strength/static load.