On July 31st, the folks at the Winfield VFD (Carroll County, Maryland) put the new automatic air primer to test on their Engine 142 when they attempted to draft through 100-feet of 6-inch suction hose.

The automatic air primer is from Trident Emergency Products and is the first automatic air primer installed on a pumper in the U.S.A Engine 142 is a 2007 pumper built by 4-Guys Firetrucks and is equipped with a Hale QMax fire pump. The folks at Winfield had the electric, rotary vane primary removed and had it replaced with the automatic air primer on July 26th.

After a few days of training, they decided to give the air primer a "real" test so they decided to try and draft through all of the suction hose owned by the FD - which amounted to 100-feet of 6-inch, lightweight suction hose.

The crews conducted a couple of tests - the first of which involved using a dry fire hydrant. The 100-ft of suction hose was connected to the suction head and the pumper, and a 4-inch discharge line was connected to the pumper's high-flow discharge. A HoseMonster flow diffuser was used to accurately measure the flow on the discharge line.

The first test resulted in a priming time of 2:40 minutes from primer activiation to discharge pressure showing at the pump. A flow of 791 gpm was obtained.

A significant air leak was found at the suction head so a second test was conducted using a floating suction strainer in lieu of the dry hydrant. The second test resulted in an even faster priming time of 1:53 minutes from primer activation to discharge pressure showing at the pump. A flow of 1,012 gpm was obtained.

The lift for both tests was under 10-ft.

The automatic air primer has no moving parts and has the ability to automatically engage when a loss of prime begins to occur. The "100-ft" suction hose test showed the ability of the primer to run for extended periods of time without worry about damage to the primary as usually found with a traditional, rotary vane electric primer.

We will post the complete test findings at a later date.

The folks at the Winfield VFD have been a long-time supporter of rural water supply operations in Central Maryalnd and we thank them for sharing their findings with us.