In the 1940’s the Hoffer valve  was born, In it’s day a useful tool.  But in 2021 and beyond not as good. Another Model T product still in use today.   Today due to the advances in Automation and the Underwater Pump, many of the old systems are outdated. We have used the by pass valve in the past and have done many production studies with or without the valve being used. Our observation in a underwater dredge application was this. Operators often set the valve at a conservative setting. This made running the dredge easier and need for less adjustments made by the operator. Actual production was  higher when a dredge operator ran with the valve off.  Additionally noted was a false reading when valve is used due to dilution. Basket packing with clay or rock . Caved in due to valve. Our system does modulate with a close bias to correct these problems. The use of the valve is somewhat different on a hull pump . This dredge is limited by effective lift “vacuum”. In this case a bypass may help a operator run closer to the limiting factor of “max vacuum.”  This is the reason for lower production of the hull dredge. The other factor is line velocity. As the dredge increases production, pump rpm must be increased or slurry diluted. With a bypass valve, slurry is diluted to maintain velocity and production is decreased.  Our DWA-7 system is far superior to what is now offered in the market for hull or deck pump dredges.