Why are lifting chains connected to submersible pumps when the pumps are too heavy to be lifted out by hand, and pump engineers use a winch that hooks directly on to the pump?
If you've ever opened up the manhole cover over a submersible pump station, you may have noticed pump lifting chains hanging down from the top of the pit and hooked on to the pumps.
Obviously these are for sliding the pumps up the guide rails, but actually if you give them a tug then in many cases the pumps are much too heavy to be safely lifted out by hand, even with two people. And pump engineers always use a proper lifting winch that hooks on to the pump itself. Pump lifting chains in fact are an important part of the submersible pump station, and here's why.
When something goes wrong with the pumps, the pump station fills up and the high level alarm goes off. Pump engineers are called in to assess the issue, and one of the things they will very likely need to do is remove the pump. However, there's no way to hook the winch onto the pump which is at the bottom of the pit under a couple of metres of water (or more). Now pump lifting chains have an important job to do.
Accessed directly below the manhole cover, the lifting chain can be connected to the winch in one of the chain's 'lifting eyes' (see below picture), and the pump safely removed from the pump station. When the problem's fixed, the pump lifting chains can again be used to lower the pump back down to pump away the water that's built up in the pump station.
It's easy to overlook the importance of the pump lifting chains because they're often not used from one year to the next, but when you do need them...you do need them! Part of our routine servicing includes checking the lifting chains. Don't compromise with a piece of rope, or rusty old chains, or even a standard chain (without lifting eyes) because you may well regret it one day.