STOW CP-20H — GENERAL INFORMATION
APPLICATION
The STOW Model
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 trash pump is powered by an 4.0 horsepower air cooled 4- stroke, single cylinder HONDA
Oil Alert Feature
In the event of low oil or no oil, the HONDA
Standard Centrifugal Pump
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 |
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Feet (Meters) |
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Sea Level | 10.0 (3.048) |
| 15.0 | (4.572) | 20.0 (6.096) |
| 25.0 (7.620) | |||
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2,000 (610) | 8.80 | (2.680) |
| 13.2 | (4.023) | 17.6 | (5.364) |
| 22.0 (6.705) | |
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4,000 (1,219) | 7.80 | (2.377) |
| 11.7 | (3.566) | 15.6 | (4.754) |
| 19.5 | (5.943) |
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6,000 (1,829) | 6.90 | (2.103) |
| 10.4 | (3.169) | 13.8 | (4.206) |
| 17.3 | (5.273) |
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8,000 (2,438) | 6.20 | (1.889) |
| 9.30 (2.834) | 12.4 | (3.779) |
| 15.5 | (4.724) | |
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10,000 (3,048) | 5.70 | (1.737) |
| 8.60 (2.621) | 11.4 | (3.474) |
| 14.3 | (4.358) | |
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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.
Table 4 shows percentage drops in performance as elevation increases.
Table 4. Performance Loss at Various
Elevations
Altitude | Discharge Flow | Discharge Head | |
Feet (Meters | |||
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Sea Level | 100% | 100% | |
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2,000 (610) | 97% | 95% | |
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4,000 (1,219) | 95% | 91% | |
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6,000 (1,829) | 93% | 87% | |
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8,000 (2,438) | 91% | 83% | |
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10,000 (3,048) | 88% | 78% | |
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PAGE 12 — STOW