What Is the Difference Between Horizontal Split Case vs End-Suction Pump?

Centrifugal pumps are the most common pumps used in firefighting applications; in this article, we will explain the fundamental differences between the two most common types of centrifugal pumps, "End Suction" and "Horizontal Split Case," and compare the capacities, initial costs, maintenance, and space requirements for each type.

The suction nozzle of a single suction pump is located on the other side of the casing from the stuffing box, with the face of the suction nozzle perpendicular to the shaft's longitudinal axis. The impeller is frequently installed on the end of a shaft that is "overhung" from its bearing supports, which is known as a "overhung hung impeller."

Close coupled end suction pumps have the impeller installed directly on the motor shaft, while independently coupled end suction pumps have the impeller mounted on a separate pump shaft supported by its own bearings.

The casing of a centrifugal pump that is divided parallel to the shaft. The impeller is commonly positioned on a shaft with bearings at both ends, and is known as a "Impeller Between Bearing" type. Horizontal split pumps are available in single stage or multistage configurations.

CAPABILITIES ARE AVAILABLE IN A VARIETY OF SIZES

Because the pump casings are often heavier and designed to handle higher working pressures, the horizontal split case pumps can withstand the large amount of vibration and thrust forces often caused by water turbulence in the suction piping. Furthermore, the design of "Impeller between bearing" and because the water enters the two sides of the impeller (double suction), these pumps can withstand the large amount of vibration and thrust forces often caused by water turbulence in the suction piping.

Because water enters one side of the impeller and because of the "Impeller overhung" design, end suction pumps cannot be used for high water flow applications, often not surpassing 1500 gpm.

INITIAL COST: Horizontal split case pumps are often heavier and cost more than comparable end suction pumps due to the wide flanges required for the split casing sealing joint, larger impeller, and overall huge size. However, because end suction pumps have a long operating life, the cost of maintenance and downtime may outweigh any initial cost savings.

MAINTENANCE: Horizontal split case pumps are simple to maintain since the top half of the casing may be removed, exposing the internal components (bearing, shaft, impeller, and so on) without disrupting or moving the motor.

Maintenance of end suction pumps, on the other hand, is more challenging due to their compact construction; for example, removing the impeller necessitates removing the motor to make room for pulling the impeller back out of the casing.

STORAGE IS REQUIRED

End suction pumps have the advantage of saving space due to their compact form, whereas horizontal split case pumps require more space.