Multiquip QP305SLT general information, Application, Power Plant, Oil Alert Feature, Suction Lift

general information

APPLICATION

The QP305SLT/QPT305SLT centrifugal pump is a high pressure pump designed to be used for dewatering applications. The suction port on the QP305SLT/ QPT305SLT uses a 3-inch diameter opening. There are three discharge ports on the pump, 2 are 1-inch in diameter and the third is 1.5-inches in diameter. This pump can discharge water at a rate of approximately 145 gallons/ minute (gpm) or 550 liters/minute (lpm).

Centrifugal or self-priming pumps are designed to purge air from the suction line and create a partial vacuum in the pump body. The reduced atmospheric pressure inside the pump allows water to flow through the suction line and into the pump body.The centrifugal force created by the rotating impeller pressurizes the water and expels it from the pump.

Power Plant

This centrifugal pump is powered by an 9.5 HP, air-cooled 4-stroke, single-cylinder HONDA GX340 gasoline engine that incorporates a low “Oil Alert Feature”.

Oil Alert Feature

In the event of low oil or no oil, the HONDA GX340 engine has a built-in oil alarm engine shutdown feature. If the oil level is low the engine will automatically shut down.

Standard Centrifugal Pump

Standard centrifugal pumps provide an economical choice for general purpose dewatering. These types of pumps should only be used in clear water applications (agricultural, industrial, residential) as they have a limited soild handling capability of only 10% by volume.

Suction Lift

This pump is intended to be used for dewatering applications and is capable of suction lifts up to 25 feet at sea level. For optimal suction lift performance keep the suction hose or line as short as possible. In general always place the pump as close to the water as possible.

Pump Support

The pump should always be placed on solid stationary ground in a level position.

NEVER place the pump on soft soil. The suction hose or pipe connection should always be checked for tightness and leaks. A small suction leak in the hose or fittings could prevent the pump from priming.

Elevation

Higher elevations will effect the performance of the pump. Due to less atmospheric pressure at higher altitudes, pumps DO NOT have the priming ability that they have at sea level. This is due to the “thinner air” or lack of oxygen at higher altitudes.

A general rule of thumb is that for every 1,000 feet of elevation above sea level a pump will lose one foot of priming ability.

For example, in Flagstaff, Arizona where the elevation is approximately 7,000 feet, the pump would have a suction lift of only 18 feet rather than the 25 feet at sea level. Table 3 shows suction lift at various elevations.

Table 3. Suction Lift at Various Elevations

Altitude

FeetSuction Lift in Feet (Meters) (Meters)

Sea Level		10.0 (3.048)	15.0 (4.572)	20.0 (6.096)	25.0 (7.620)
2,000	(610)	8.80 (2.680)	13.2 (4.023)	17.6 (5.364)	22.0 (6.705)
4,000	(1,219)	7.80 (2.377)	11.7 (3.566)	15.6 (4.754)	19.5 (5.943)
6,000	(1,829)	6.90 (2.103)	10.4 (3.169)	13.8 (4.206)	17.3 (5.273)
8,000	(2,438)	6.20 (1.889)	9.30 (2.834)	12.4 (3.779)	15.5 (4.724)
10,000 (3,048)		5.70 (1.737)	8.60 (2.621)	11.4 (3.474)	14.3 (4.358)

Table 4 shows percentage drops in performance as elevation increases.

Table 4. Performance Loss at Various Elevations

Altitude		Discharge Flow	Discharge Head
Feet (Meters)
Sea Level		100%	100%
2,000	(610)	97%	95%
4,000	(1,219)	95%	91%
6,000	(1,829)	93%	87%
8,000	(2,438)	91%	83%
10,000 (3,048)		88%	78%

page 12 —QP305SLT/QPT305SLT CENTRIFUGAL PUMP • operation and parts manual — rev. #1 (10/11/10)