Filtration Equipment Repair & Refurbishment-Filter Plate

Fault Probable Reason Corresponding Solution

1. The filter plates are damaged.

A. Feed hole is blocked.  A. A few filter plates near the feed inlet are damaged. In accordance with the initial judgment, it is because feed inlet is blocked, the concentration of the slurry is too high, or the feed hole is not cleaned in time. Dilute the filtrate.

B. Feed pressure is too high. B. When there is an anti-pressure or the displayed pressure in the pressure gauge is more than the limit in the nameplate. It indicates that the feed pressure is high. Solution: adjust the pressure control system at the feed end.

C. The material concentration is much higher and liquidity is too poor.  C. Lower properly the material concentration and improve the material liquidity.

D. The feed temperature is too high. D. Firstly, please find out the material temperature. When the filtering material temperature is higher than the mounted filter plate temperature, please inform the reason to the customer and change the appropriate filter plate or make the slurry temperature cool before filtering.

E. The filter cloth is damaged and the liquid outlet is blocked. E. The filtrate in a few water mouths is turbid because the filter cloth is damaged. There is no liquid from the water mouths because the liquid outlet is blocked. Please replace the filter cloth and clean the liquid outlet. Make sure the filtrate can be flowed out normally and clearly.

2. The filtrate is not clear.

A. The filter cloth is broken. A. Please observe the filtrate clear or turbid. If the filtrate from individual water mouth is turbid, you can judge the filter cloth here is damaged. Please check and analysis the reason, if it is caused by improperly using, please introduce the correct usage to the customer and replace the filter cloth.

B. The filter cloth is chosen improperly. B. Please bring the filter medium back to the company for testing and select appropriate filter cloth. Or, please replace the filter cloth in accordance with the correct model provided by the customer.

C. The protection work about feed inlet is not so good. C. It is because the protection work about feed inlet is not so good if there is leakage in the feed inlet leak. Please check the inlet flange, gasket, and the connection condition. If there is any damage, replace the corresponding parts, then clean up the gasket and tighten the feed inlet.


D. The filter cloth opening is too large. D. Please replace the filter cloth.

E. It is open with the filter cloth stitching points. E. Remove the filter cloth and sew up it again, then explain the precautions to the customer.


Note: at the beginning of the filter work, the feeding valve should be slowly opened. At first, the filtrate is turbid and then clear, which is a normal situation.

3. There is running material between filter plates.

A. The clamping force is insufficient. A. There is running material between filter plates, which can be preliminarily judged because of insufficient clamping force. Generally, the clamping force is: rubber filter plate (8~10Mpa); Plastic filter plate (15~20Mpa); Cast iron filter plate (20~25Mpa). When the clamping force is insufficient, please increase the pressure slowly but do not exceed the rated pressure. In the case of ensuring no leakage, the reduced pressure can extend the service life of the filter equipment. Start the pressure button, and the motor will rotate clockwisely, then drive the oil pump. When filter plate is clamped, adjust clockwisely the high-pressure overflow valve, watch electric-contact pressure gauge and adjust the pressure within the operation range above mentioned.

4. Cannot move forward or backward.

A. Oil level is not enough. A. When the oil mark is not able to display the oil level, it is indicated that you should fill oil to ensure the pump station is operating normally.

B. The high-pressure or low-pressure overflow valve is jammed or damaged. B. Please disassemble and clean it. If it still cannot work properly, maybe the overflow valve is damaged. Please replace it.

C. Plunger pump is damage. C. When the oil circuit is not smooth or can't be supplied, you can judge that the plunger pump is damaged. Please clean it. If it cannot work normally, please replace it.

D. The motor rotation direction is wrong. D. Observe whether the motor fan turns clockwise, otherwise, you can judge that the motor is connected in opposite direction. Please exchange any two wires at the motor feed wire end.

E. There is no action about solenoid directional valve. E. Please clean or replace the solenoid directional valve.

5. Cannot stop after pressing.

A. Electric-contact pressure gauge adjustment value is too high. A. Adjust the adjusting screw on the electric-contact pressure gauge with a screwdriver to lower the upper limit.

B. The electric-contact pressure gauge is damaged. B. Replace the pressure gauge when you found that the pressure gauge pointer is not sensitive or the pointer cannot return to zero.

C. The overflow valve is set too low. C. Adjust the adjusting screw on the electric-contact pressure gauge with a screwdriver to adjust the lower limit until 5Mpa.

6. The pressure cannot be retained.

A. There is oil leakage from the pressure retaining line.  A. Observe whether the pipeline is broken, and replace the pipe or tighten the connecting nut.

B. The pressure retaining valve is stuck or damaged. B. Please clean the valve. If it cannot work normally, please replace it.

C. The relief valve is stuck or broken. C. Please clean the valve. If it cannot work normally, please replace it.

D. The oil cylinder gasket is worn seriously. D. Open the sealing part and inspect the gasket damaged part and the oil cylinder scratches and bumps. If the oil cylinder is slightly worn, you can repair it with metallographic sandpaper or oil stone, and replace the gasket.

E. The non-return valve is damaged. E. Please replace it.

7. Crawling

A. Oil level is not enough. A. The oil level of the oil level gauge should be refueled at more than 2/3 of the oil level.

B. There is air in the cylinder. B. Unscrew the cylinder and release the air into the cylinder.

C. The cylinder matches too tight with the piston. C. Please use it for a certain time.

D. The concentration of hydraulic oil is high. Please use 32#~46# antifriction hydraulic oil.

8. The main beam is bending.

A. The base foundation is rough and the freedom is insufficient. A. The correct installation method is that: do not fix the oil cylinder holder end foundation, fix the thrust plate end and the foundation should be flat.

B. The filter plate is put unevenly. B. When the filter plate is put unevenly, the force of the pressure plate will be tilted to one side, which will bend the main beam. In this case, please adjust the filter plate.

C. There are impurities on the filter plate surface. C. Once each process is completed, the filter plate must be cleaned and then pressed again.

D. The legs are not touching the ground firmly. D. Observe whether the legs are raised when pressed, if so, please add the pads under the legs.

E. The foundation is uneven. E. Find out the foundation level, loosen the beam bolt to adjust the beam, make the diagonal length difference within 0.05%, fix the beam bolt, then rebuild the foundation.

9. The filter plate is lifted up.

A. The installation base is not even. A. Rebuild the foundation to ensure the foundation is flat.

B. There are impurities on the filter plate surface. B. Please clean the impurities on the filter plate surface before pressing.

C. The piston rod is deviated. C. When the spherical convex R of the piston rod is greater than that of the spherical cushion, the spherical surface should be fixed to the concave R of the spherical cushion. Adjust the diagonal of the beam to within 0.05%. The pressure plate flange is not welded in the center position and should be cut down to find the positive center welding.

10. Oil pressure is not enough.

A. Oil level is not enough. A. Fill 32#~46# anti-wear hydraulic oil over 2/3 of the oil level gauge.

B. Oil viscosity is too high or oil temperature is too low. B. Replace the oil with lower viscosity or heat the tank.

C. The overflow valve is improperly adjusted or damaged. C. The high-pressure overflow valve is adjusted too low so that the pressure cannot rise to the required pressure. Rotate high-pressure relief valve and adjust the value to 25Mpa.

D. There is leakage in the valve. D. The overflow valve is adjusted correctly, but the pressure still cannot be rise. Maybe it is because of the valve leak, please replace the overflow valve.

E. Oil cylinder gasket is worn. E. Please replace the gasket.

F. The solenoid valve is not in position. F. Please repair or replace it.

G. Oil pipe, joint, pipeline is leakage or gasket is damaged. G. Apply clean butter to each end of the suction passage to check for air leakage.

H. Plunger in plunger pump is worn seriously. H. Please replace the plunger pump.