Reasons For Packing Seal Failure Of Long Shaft Pump And How To Repair It

Nov 12, 2024

Long shaft pump is an energy-saving water intake machinery equipment, which is often used in factories, hospitals, hydropower stations, and water treatment plants due to its high energy-saving efficiency, stable operation, and moderate price.

Generally speaking, long shaft pumps have two types of seals: mechanical seals and packing seals, and the choice of which one to use depends on the user's needs.

The precision and manufacturing process of mechanical seals are relatively complex, and the relative cost is relatively high. The production and manufacturing of packing seals are relatively simple and cost-effective, so they are more widely used.

The advantage of packing seal for installation and maintenance is that if the packing seal of the long shaft pump fails, what are the reasons? How to repair it better?

Reasons for the malfunction of the stuffing box

① The packing in the pump packing box is not tightly compressed.

② The packing method in the water pump packing box is incorrect or the packing has worn out or its properties have changed.

③ The pump shaft of the long shaft pump is bent.

④ The cooling water entering the packing box is not clean, resulting in wear and displacement of the pump shaft.

How to repair?

① Firstly, use a wrench to tighten the gland screw of the stuffing box and tighten the packing. If the fault cannot be eliminated, then open the stuffing box again to check the filling condition of the packing; If the filler is wrapped too loosely or the number of layers is insufficient, it should be re wrapped tightly and additional filler should be added.

② Open the packing box of the long shaft pump and check the filling quality and properties of the packing. If the filling method is improper, the filling should be refilled according to the correct method; If there is wear or variation in the properties of the filler (such as uneven thickness, dryness, hardening, etc. of asbestos rope), a new filler should be replaced. Packing method: Generally, asbestos ropes are woven into various sizes with different thicknesses, soaked in butter, and then pressed into strips with a square cross-section. Graphite powder is applied to the outer surface, and the appropriate size of packing is cut into several sections according to the thickness of the shaft and loaded into the packing box. The number of layers of packing should be appropriate, usually 4-6 layers, and the packing box cover should be tightened with a wrench (usually with a water drop of 60 drops per minute).

③ Open the long shaft pump body, remove the water pump shaft and perform calibration. Then calibrate or replace according to the verification results.