What Causes Screw Pump Seal Failure? Key Factors You Shouldn’t Ignore

 What Causes Screw Pump Seal Failure? Key Factors You Shouldn’t Ignore

In industrial fluid handling, screw pumps are widely used for their stable flow, low pulsation, and strong ability to handle high-viscosity or particle-laden media. However, in real-world applications, one issue still shows up frequently: seal failure.

From an engineering perspective, it’s fair to say that choosing the right pump is only half the job—whether the sealing system is reliable often determines how long the pump can run without trouble.

So what actually causes screw pump seal failure? Here are the key factors.

1. Fluid Characteristics: The Most Overlooked Factor

Many users focus on flow rate and pressure, but overlook how the fluid itself affects sealing performance.

Typical risks include:

High viscosity → increases friction and heat

Solid particles → cause abrasion and scratches

Corrosive media → attack sealing materials

Crystallizing fluids → deposit around seal faces

👉 In many cases, seal failure is not due to poor design, but incorrect material selection.

2. Dry Running: The #1 Cause of Seal Damage

Dry running is one of the most common reasons for mechanical seal failure.

When the pump runs without fluid:

No lubrication between seal faces

Rapid temperature rise

Severe friction damage

👉 Result: seal faces burn, crack, or fail quickly.

Recommendation:

Always ensure proper priming or use dry-run protection systems.

3. Installation & Alignment Issues

Some failures are not caused by the pump itself, but by improper installation.

Common issues:

Misaligned coupling

Shaft deviation

Excessive installation stress

These lead to:

👉 Uneven load on seal faces → accelerated wear → early failure

4. Abnormal Operating Conditions

Operating outside design limits can significantly shorten seal life:

Overpressure

Excessive speed

High temperature

👉 These conditions cause overheating and material degradation in seals.

5. Incorrect Seal Type Selection

Screw pumps typically use:

Mechanical seals

Packing seals

If the seal type doesn’t match the working condition:

Corrosive media without proper materials

High temperature without suitable design

👉 Leakage and frequent maintenance will follow.

6. Lack of Maintenance

Routine inspection is often underestimated:

No periodic seal checks

Delayed replacement of worn parts

Insufficient lubrication

👉 Small issues accumulate and eventually lead to failure.

7. How to Reduce Seal Failure Risks

From practical experience, three key steps help:

Understand fluid characteristics during selection

Choose a reliable manufacturer and proper sealing design

Ensure correct installation and regular maintenance

For a more detailed explanation of screw pump working principles, advantages, and selection methods, you can refer to this guide:

👉 https://www.scpv.cn/news/874.html

Conclusion

Seal failure in screw pumps is rarely caused by a single issue—it’s usually the result of multiple factors combined. Addressing selection, installation, operation, and maintenance together is the only way to ensure long-term reliability.

Manufacturers with real engineering experience, such as Shanghai Shangcheng Pump & Valve, focus not only on supplying equipment, but on delivering complete solutions tailored to actual working conditions.