Self Priming Trash Pump

Self priming trash pump, also called self priming sewage pump is commonly used in construction projects where there is an open body of water that can be accessed by the piping or hose. This pump can handle clean, muddy, mucky, or sandy water with solids up to 2 inches in diameter (depending on pump size) and between 10 to 25 percent by weight. Applications include pumping unwanted water from excavations, flooded basements, manholes, utility vaults, mining work, retention ponds, lakes and barge holds. Engine driven trash pump is very popular in the construction industry because of their reliability, versatility, and durability under a variety of site conditions. Especially 6 inch trash pump and 8 inch trash pump.

Trash pumps are available in either wet prime pump or dry prime pump versions. Wet prime pump requires that the casing be filled with water before operation. Dry prime pump utilizes an external priming system, usually a compressor or a vacuum pump, to assist in purging air from the suction line of the pump system.

These types of pumps typically have high suction lifts and relatively high discharge heads, as well as a simple design with few parts. However, they are not a good choice for pumping thick mud. And when there is only a small quantity of water to pump, priming will be lost.

Improper operation of self priming pump - High lift pump for low lift pumping

Many people think that the lower pump’s head to be, the smaller motor power to use. When they select a pump, they prefer high head pump.

In fact, when the pump model is determined, the power consumption is proportional to the actual flow of the pump. The flow rate of the pump will decrease with the increase of the lift, so the higher the lift, the smaller the flow and the smaller the power consumption.

Conversely, the lower the lift, the greater the flow and the greater the power consumed. Therefore, to prevent motor overload, it is generally required that the actual pumping stroke of the pump should not be less than 60% of the nominal head. Therefore, when high head pump is used for low head pumping, the motor is easily overloaded and heated and the motor can be burnt. If it is used in an emergency, a gate valve (or a small outlet with wood or the like) for adjusting the amount of water must be installed on the outlet pipe to reduce the flow and prevent the motor from being overloaded.

Pay attention to the temperature rise of the motor. If the motor is overheated, turn off the flow of the small outlet or shut down. This is also easy to misunderstand. Some operators think that blocking the water outlet and forcibly reducing the flow will increase the motor load. In fact, on the contrary, the gate valve is installed on the outlet pipe of the regular high-power high-lift self-priming pump draining and discharging unit. In order to reduce the motor load during the start of the unit, the gate valve should be closed first, and then the gate valve is gradually opened after the motor is started.