Figure up all the open area in your guard, and then compare it to the cross sectional area of the pipe. The longer the guard, the greater the open area.
If the guard went straight across, flat to the end of the pipe, your assumption would be correct. The guard is cone-shaped, so I suspect the total area of the openings exceeds the cross sectional area of the pipe.
The guard may modify the way the water goes in by creating vortices at full flow. Those calculations could be approximated with a hydraulic study, which the company said it did not do. Personally, I would leave the guard in place, otherwise some sticks could get across the opening, trap other debris, and block a large portion of the flow.
Well, If my "seat of the pants" calculations are correct, then you are correct. I came up with 452.44" for the cross sectional area of the pipe, and 615.83" for the total area of the openings on the pipe when figured one way, and 464" figured in another way...so if those are correct then they would both be larger than the cross sectional area of the pipe. Thanks.
