Guidance on Circulation Pumps

1.Precautions for Hot Water Circulation Pumps

Circulation pumps may encounter issues during operation, such as burnout and excessive energy consumption. Understanding precautions during use can extend the pump's lifespan, increase operational cycles, and prolong service life.

1. Before startup, open the outlet valve. Depending on the hot water circulation pump model, open the outlet valve gradually. Once operation stabilizes, fully open the valve.

2. Before starting the high/low-temperature circulation pump, open the inlet valve.

3. When starting the motor, listen carefully for any dry-running sounds from the hot water circulation pump. If dry-running occurs during inspection, check whether the water level exceeds the pump body.

4. Verify that the pressure gauge shows air pressure and inspect whether the water level is above the pump body.

5. After starting the circulation pump, touch the motor with the back of your hand to check for overheating. Only leave the area after confirming normal operation.

6. If unusual noises or excessive noise are detected, report immediately and await maintenance.

7. If the circulation pump or motor seizes, fails to operate, produces excessive noise, or experiences a phase loss in the motor wiring, immediately press the emergency stop button. After shutdown, report the issue and await maintenance.

8. Slight condensation on the pump during inspection is normal and requires cooling. Report immediately if heavy condensation occurs and await maintenance.

9. Ensure valves are opened before starting pumps. When stopping pumps, shut down the machine first, then close valves sequentially. Circulating water pump valves should remain in the open position.

2. How to install a circulation pump

During autumn and winter, the weather turns cold. Many users rely on various heating devices for warmth, making the installation of a hot water circulation pump essential. Regarding these pumps, users often have numerous questions, with the most common being how to install them after purchase. Below, I will briefly outline the installation steps for a hot water circulation pump, hoping to assist users during the process. Install the hot water circulation pump near the faucet to minimize piping length.

1. Before installation, thoroughly inspect the pump's operational path for potential impacts. During operation, check the hot water circulation pump's flow channel for hard objects (e.g., rocks, iron filings) to prevent damage to flow components.

2. During installation, the weight of the piping should not be borne by the pump, as this may cause damage.

3. Before connecting pipes, rotate the pump's rotor section. It should move freely without friction or binding. If resistance occurs, immediately disassemble the pump to investigate the cause.

5. For applications requiring lift height, install a foot valve. Minimize bends in the inlet pipe and ensure no leaks (water or air) to maintain pumping efficiency.

6. Prevent debris ingress. If the flow path may become obstructed, install a filter before the inlet.

7. For maintenance convenience and safe operation, install a control valve on both the inlet and outlet piping, along with a pressure gauge near the inlet. For high-lift pumps, install a check valve before the outlet gate valve to prevent water hammer. The check valve addresses power interruptions like sudden blackouts, ensuring optimal operating conditions and extending service life.

3. Maintenance and Troubleshooting of Circulation Pumps

Pump Maintenance

1. Operational Maintenance:

• The inlet pipeline must be filled with liquid. Prohibit prolonged operation of the pump under cavitation conditions.

• Regularly inspect the motor current value, which must not exceed the motor's rated current.

• After prolonged operation, if increased noise and vibration occur due to mechanical wear, stop the pump for inspection. Replace wear-prone parts and bearings as necessary. The general overhaul interval for the unit is one year.

2. Mechanical Seal Maintenance

• Use clean, particle-free media for mechanical seal lubrication.

• Never operate the mechanical seal under dry-running conditions.

• Before startup, manually rotate the motor shaft several times to prevent sudden start-up from fracturing the graphite ring.

• Acceptable seal leakage is 3 drops per minute. Exceeding this requires inspection of the mechanical seal assembly.

3. Winter Freeze Prevention Measures

During winter, pumps and pipelines are prone to freezing, which can cause pipeline damage, pump deformation, or failure to draw water. Implement the following cold protection measures:

(1) Bury horizontal pipelines at least 30 cm below ground level.

(2) To prevent residual liquid from freezing inside the pump during winter, unscrew the drain plugs in advance to completely drain the pump.

Caution: Do not cover the motor or pump with flammable materials for frost protection to prevent fire hazards.

4. After prolonged storage before use

If the motor fails to start after power connection when using a pump stored for an extended period, this is likely due to solidified or adhered debris inside the pump. In this case, disconnect the power supply. Insert a screwdriver into the groove at the motor's rear end and rotate it to turn the pump. It is recommended to rotate it at least 15 times. After rotation, if the pump shaft turns smoothly without any binding, the pump can be restored for use.

Causes of Malfunctions and Troubleshooting Methods