In the scene of a fire, there are many kinds of risks including heavy smoke and dust, flash burn, drop off wall's coat lime, broken of fire hydrant, the panic crowd ……etc. All will bring serious tests to the escape equipment. An out of control fire can suddenly change working environment of escape device, therefore, our fire escaper must withstand severe tests, besides National regulations, some of them are list below. 1) Carrying chain: It can bear a pulling force up to 3.3 tons for 30 minutes without damage; after burning in the flame of liquefied gas for 15 minutes, it still maintains a breaking force more than 2.3 tons; It can normally work after buried in sand or soaked in water; After 300 times of tests with Speed reducer weighted 80-110kg, the chain still works well. 2) Speed reducer: Speed reducer which is fixed to the carrying chain can bear 700 kg of pulling force for 30 minutes without damage; It can work normally after buried in mud for 1 hour; When buried in sand, it can work after shake off the sand in few seconds; It can work even after heated to 392°F (200°C) for 20 minutes.
