Relay Pump Operations: Who Says It's Just for the Long Lay?
Flow Test #5
Flow test #5 was set up similar to test #4 in that it involved the use of the same type of hose, a very similar performance from the hydrant, and the comparison tests between the Akron and Humat HRVs. The only thing that was different was that the supply line was 500 feet long. Again, the numbers for the supply line lay from hydrant pressure followed the same path as they did in test #4. The evolution that did not use the HRV had a flow of 797 GPM. The Akron valve reduced the flow to 765 GPM while the Humat moved 775 GPM.
The relay flows were as follows with no valve 1440 GPM, with the Akron valve, 1090 GPM, and with the Humat valve 1128 GPM. The stopping point for the relay operations was a water issue. The pumper at the hydrant ran out of water. Adding a second and sometimes a third line from the hydrant to the source pumper can improve the flows. In this evolution it probably would not have help much but on strong hydrants it could make a big difference.