As we approach our September 30th research project on suction strainer performance, we take a couple minutes to look at barrel strainers. A simple visual display of barrel strainers on the tailgate of a pick-up truck is a good example of the differences among nine strainers that all fit 6-inch suction hose. While there are a number of variables that effect the performance of a pumper at draft: lift, altitude, water temperature, rated pump capacity, suction inlet used, condition of the pump seals/packing, suction hose size, etc...the strainer selection is pretty darn important!
It is easy to leave out the "strainer" as a variable in the drafting process - when in fact, the choice of strainer - next to lift - might be the biggest impacting decision made in the drafting process. During our travels across the USA and Canada running water supply drills, we have seen large capacity pumpers struggle to achieve flows of 1,000-1,500 gpm all because of the strainer chosen for the end of the suction hose.
We do know that in most cases, a barrel strainer is a high-performing strainer. The problem of course, is making sure that you have one that matches your pumper's ability to pump from draft, not one that matches the compartment size in which to plan to store it.
As far as low-level and floating strainers go, well those are topics for another article.