Hand Chain Hoists

The ignition risks in a standard hand chain hoist are mechanical rather than electrical: chain moving through the load wheel, the hand chain running over its sheave, hooks contacting steelwork, and the impact of a load being landed. An explosion protected hoist addresses each of these, typically through bronze plating on the load chain and hooks, non-sparking materials at contact and impact surfaces, and design changes that prevent steel on steel friction in normal operation.

The result is a hoist that looks and operates like a conventional one, with the same gearing and the same brake principle, but which can be introduced into a classified area.

Start with the zone classification from your DSEAR assessment, then match the equipment category, gas group and temperature class before you look at capacity. Once the rating is settled, specify capacity and height of lift as normal, and remember that the standard drop may not suit the structure you are hanging it from.

The suspension must carry an equivalent rating. Hanging a certified hoist from an uncertified trolley or beam clamp defeats the purpose, as does fitting a standard chain container.

Keep the plating intact. Damage that exposes the base steel compromises the spark resistance, so inspect chain and hooks for wear through the plating and withdraw the unit if found. LOLER thorough examination applies at least every twelve months, alongside the checks required to maintain the explosion protection certification.