A slurry pump operates in some of the harshest conditions in the mining and mineral processing industry. Abrasive particles, high pressure, and continuous duty all place heavy stress on the pump’s sealing system.
To ensure long-term reliability and prevent costly leaks, a seal pressure test is an essential step during manufacturing, maintenance, or commissioning.

What Is a Slurry Pump Seal Pressure Test?

A seal pressure test is a controlled evaluation that checks whether the pump’s sealing system—such as expeller seals, mechanical seals, or gland packing—can withstand a specified internal pressure without leaking.

It’s typically performed before the pump is put into service or after overhaul to ensure that the pump is safe, reliable, and ready for operation.

Why Is the Test Important?
1. Prevent Leakage and Unplanned Shutdowns

Seal failures can cause slurry leakage, equipment contamination, and unexpected downtime. Pressure testing ensures that the seal can handle operating pressure safely.

2. Confirm Manufacturing or Repair Quality

Any machining errors, improper installation, or material defects will show up during a pressure test—before the pump reaches the site.

3. Protect Pump Bearings and Internal Components

Leakage into the bearing assembly can cause rapid bearing failure. Testing ensures the sealing system is properly aligned and functional.

4. Reduce Maintenance Costs

Catching seal issues early avoids high repair costs later.

How the Seal Pressure Test Is Performed

The exact steps vary by pump model and seal type, but the general procedure includes:

1. Prepare the Pump

Install the sealing system (packing, lantern ring, expeller, or mechanical seal) correctly.

Ensure the pump casing, cover, and stuffing box are fully assembled.

2. Seal the Suction and Discharge Ports

To allow internal pressurization, the suction and discharge flanges must be closed using blind covers.

3. Connect the Pressure Testing Equipment

A water source or hydraulic pressure pump is connected to the casing or stuffing box.

A calibrated pressure gauge is installed to monitor pressure.

4. Increase Pressure Gradually

Pressure is applied step-by-step up to the specified test pressure (usually 1.5× the pump’s working pressure).

Hold the pressure for a certain duration, often 5–10 minutes.

5. Inspect for Leakage

Check:

Stuffing box/packing area

Mechanical seal faces

Expeller ring and expeller cover

Casing joint surfaces

Any visible water leakage indicates improper sealing.

Acceptance Criteria

A slurry pump passes the seal pressure test if:

No visible leakage

Tiny seepage at packing may be acceptable depending on system design.

Pressure remains stable

A drop in pressure signals internal leakage.

 All components remain structurally intact

No deformation or abnormal noise.

Best Practices for Accurate Testing

Use clean water instead of slurry to avoid abrasion during the test.

Always vent trapped air before pressurizing.

Follow manufacturer-recommended test pressure and duration.

After the test, re-check packing or seal installation before shipment or startup.

Conclusion

A slurry pump seal pressure test is a vital procedure that guarantees pump safety, performance, and reliability. By verifying sealing integrity before operation, companies can avoid unexpected failures, extend equipment life, and maintain smooth production.