Reliable Water Supply from Deep Wells — LC Long-Shaft Pump
The LC Long-Shaft Deep Well Pump is a vertical pumping system designed for extracting water from deep wells, open reservoirs, and underground sources. Chaodun Pump has been manufacturing these pumps for years, and they are widely used in power plants, water treatment facilities, agricultural irrigation, fire protection systems, and municipal water supply projects across Southeast Asia including Thailand, Laos, and Vietnam.
This pump features a vertical arrangement where the pump seat and motor are installed above the wellhead or water pool. Power is transmitted from the motor through a concentric drive shaft inside the riser pipe to the impeller, creating the flow and head required for each application.
Key Features and Advantages
Optimized Hydraulic Design
The LC series uses advanced hydraulic models and structural design, delivering strong performance and extended service life. The pump maintains high efficiency with a gradually sloping efficiency curve, providing a wide operating range and noticeable energy savings.
Smooth and Quiet Operation
Both the impeller shaft and drive shaft are supported by copper bearings, with radial shaft runout controlled within 0.15 mm. This tight tolerance ensures smooth running and low noise levels — an important factor for installations near residential areas or in noise-sensitive environments.
Flexible Material Options
The pump can be manufactured in ductile iron or multiple stainless steel grades including 2Cr13, 304, 316, 316L, and 416. This material flexibility allows the pump to handle various water conditions, from clean domestic water to slightly corrosive industrial sources.
Oil-Lubricated Closed Drive System
A special oil-lubricated closed drive system design is available, providing reliable operation in deep well installations where maintenance access is limited.
Attractive and Serviceable Pump Seat
The pump seat has an aesthetically pleasing design with an elevated motor support bracket, making mechanical seal replacement and routine maintenance more convenient.
Technical Specifications
| Parameter | Value |
|---|---|
| Minimum Applicable Well Diameter | 400 mm |
| Pump Type | Vertical Long-Shaft Deep Well Pump |
| Single-Stage Head | 18 m |
| Maximum Flow Rate (Q) | 1200 m³/h |
| Maximum Head (H) | 250 m |
| Water Temperature Limit | 80°C |
| Solid Content (by weight) | ≤ 0.01% |
| pH Range | 6.5 – 8.5 |
| H₂S Content Limit | ≤ 1.5 mg/L |
| Oil Content | None |
Model Designation Explained
Example: 400 LC 400 – 18 × 2
- 400 (prefix): Minimum applicable well diameter in mm
- LC: Vertical Long-Shaft Deep Well Pump
- 400: Rated flow rate in m³/h
- 18: Single-stage head in meters
- × 2: Number of stages
Operating Conditions
The LC Long-Shaft Deep Well Pump is suitable for applications where:
- Water temperature does not exceed 80°C
- Solid content (by weight) is no more than 0.01%
- pH value ranges from 6.5 to 8.5
- Hydrogen sulfide (H₂S) content is ≤ 1.5 mg/L
- No oil is present in the water
- Well bore is straight — no bidirectional bending is acceptable
Installation Guidelines
General Installation
The pump should not bear the weight of the connected piping, as this can cause damage. Anchor bolts must be tightened securely, and periodic inspections should be conducted to prevent loosening that could lead to vibration during startup.
Valve and Instrument Setup
Install a regulating valve on both the inlet and outlet piping. Place pressure gauges near the pump inlet and outlet. For high-head applications, install a check valve before the outlet gate valve to prevent water hammer damage during power loss events.
Startup Procedure
- Manually rotate the motor to ensure the impeller turns freely without binding
- Jog the motor to confirm the rotation direction is counter-clockwise
- Close the outlet pipe valve
- Power on the motor, and once normal speed is reached, gradually open the outlet valve to the desired operating point
- Monitor instrument readings and check motor and bearing temperature rise
Shutdown Procedure
- Gradually close the outlet pipe valve
- Cut off the power supply
- If ambient temperature drops below 0°C, drain all liquid from the pump to prevent freeze damage
Maintenance and Care
To ensure reliable long-term operation:
- Avoid prolonged operation in cavitation conditions
- Prevent motor over-current during high-flow operation
- Regularly monitor motor current to keep the pump within its design operating range
- Ensure the pump is supervised during operation
- After extended use, if noise and vibration increase, stop the pump for inspection and replace worn parts or bearings as needed — annual maintenance is recommended
- For deep well fire pumps that are not used regularly, start the pump at least once per month for no less than 15 seconds each time
Troubleshooting Guide
| Problem | Possible Cause | Solution |
|---|---|---|
| Motor does not turn and makes abnormal noise | Single-phase short circuit; one phase has no power; incorrect wiring; wrong rotation direction; deformed rubber bearing | Repair motor; restore power; correct wiring; swap connections; replace bearing |
| Low motor speed after startup | Phase winding connections reversed; voltage too low | Correct winding connections; increase voltage |
| Abnormal noise and heating during operation | Winding short circuit | Repair motor winding |
| High bearing temperature | Excessive bearing load or damage; insufficient or excess lubricant; contaminated lubricant | Replace bearing; adjust lubricant level; use correct lubricant |
| Motor current increases during operation | Voltage drop; bearing damage; impeller-to-shell friction; sand ingestion | Stop pump, restore voltage; replace bearing; adjust axial clearance; clean well |
| No water output or intermittent flow | Dynamic water level drops to screen; broken drive shaft; cracked riser pipe | Add riser pipe and shaft; inspect and repair; replace damaged parts |
| Significantly reduced water output | Deep dynamic water level; incorrect speed; clogged screen; leaking connections; stuck impeller; low power frequency; worn seal ring; excessive impeller-to-shell clearance | Add riser pipe; adjust speed; clean screen; replace parts; reassemble pump; adjust frequency; replace seal ring; reduce clearance |
| Severe pump vibration | Impeller-to-shell friction; bent shafts; worn rubber bearings; misaligned motor and drive shaft; excessive well deviation | Stop pump, adjust clearance; straighten shaft; replace bearing; realign installation; repair well or use smaller pump |
Why Choose Chaodun Pump
Chaodun Pump has years of experience in designing and manufacturing LC Long-Shaft Deep Well Pumps. Our products are exported to multiple countries and serve in critical infrastructure projects. We offer material selection guidance, custom staging configurations, and after-sales support to ensure each installation meets its specific requirements.
Whether you need a pump for municipal water supply, agricultural irrigation, industrial cooling, or fire protection reserve, the LC series provides a reliable and efficient solution for deep well water extraction.