LINE SLOPE - The desired gradual slope of the suction line downward to the water source, and the desired gradual slope
of the discharge line upward from the pump to the point where the water is delivered.
LINE, DISCHARGE or DISCHARGE LINE - Hose or Pipe connecting to the pump outlet and directing water away from
the pump. When lines are not vertical, it is preferable that they slope upward away from the pump.
LINE, SUCTION or SUCTION LINE - Hose or Pipe connecting to the pump inlet and running to the water source. When
the line is not vertical, it is preferable that it slope downward to the water source. All fittings, joints, and connections on
the inlet side of the pump must be completely air-tight. PRIME or PRIMING - Filling the pump casing with water. The
function of the pump evacuating suction line.
STARTING PRIME or INITIAL PRIME or FIRST PRIME - The pump must be filled with water the first time the engine is
started or whenever the pump is moved from one operating site to another site or whenever the suction lines are
changed or when the water evaporates to lower the level in the casing. This is the function of filling the pump casing with
water before the engine is started.
SUBMERGENCE - Primarily the suction line being sufficiently into the water source so vortexing or air cannot enter into
the suction line.
VORTEX - An action at the lower end of the suction line when it is not sufficiently submerged in the water source,
frequently visible as a whirlpool or heard as a slurping or gulping sound.
CASING - Part surrounding the impeller and having the suction (inlet) and the discharge (outlet) openings of the pump.
Sometime referred to as the VOLUTE.
FLAPPER - A type of check-valve built in the inlet opening of the pump casing.
IMPELLER - Main rotating part of pump & attached to the shaft end at the casing.
IMPELLER FACE - Front side of the impeller.
IMPETTIER SHROUD - Back side of the impeller.
MECHANICAL SEAL - An assembly part to prevent entry of air or exit of water around the pump shaft.
SEAL BODY - That part of the mechanical seal containing the spring.
SEAL COLLAR - That part of the mechanical seal having a lapped metal or ceramic face.
BHP - Brake horse power.
GPM - Gallons per minute.