Dump Site Operations #6 - Avoid Dumping on Suction Strainers
By President Mark Davis
December 25, 2014
One of the issues that can arise during a dump tank operation involving the use of multiple dump tanks is the need to offload tanker water into the primary dump tank (i.e. the tank from which the dump site pumper is drafting). When this need arises, it is important to avoid dumping water directly onto or next to the suction strainer. Dumping water onto the suction strainer - or immediately adjacent to the strainer - can cause "loss of prime" issues with the drafting pumper. This is especially true if the drafting pumper is equipped with an electronic pressure control governor and the govenor is operating in the "psi" mode. The result of this dumping action could cause the governor to "tell" the motor's ECM to return to idle speed in an effort to protect the pump from cavitation.
Granted - this situation will be a temporary event - but when water levels are running tight - any disruption in operation can impact flow on the fire ground.
Avoid this!!! if the pumper is drafting through that suction strainer, then the air-entrained water is going to cause loss of prime issues at a minimum and possibly return the motor to idle speed if an electronic governor is being used.
This turbulance is going to have an impact on the pumper's drafting operation.
When using jet siphon transfer systems, it is also important to direct their discharge points away from draft pumper suction strainers.
