IS YOUR OIL & GAS PUMP SEAL FAILING TOO OFTEN?

A mechanical seal can look perfectly suitable on paper and still fail prematurely in an Oil & Gas pump.

Why?

Because selecting the right seal is only part of the job.

One of the most damaging mistakes is allowing the seal faces to operate without adequate liquid lubrication and heat removal. This can happen during dry running, loss of flush, inadequate cooling, blocked piping, improper startup, or unfavorable operating conditions.

For an Oil & Gas engineer, the important question is therefore not simply:

It is:

That distinction can make a major difference to seal reliability.

• Right Environment
• The Mistake
• What Happens During Dry Running?
• Oil & Gas
• 5 Warning Signs
• Replacing the Seal
• Don’t Blame the Seal Too Quickly
• Prevent Premature Pump Seal Failure
• Conclusion

A mechanical seal works through controlled contact between highly finished sealing faces. The operating environment around those faces affects lubrication, temperature, wear and leakage.

Modern seal-support guidance emphasizes that temperature, pressure, vibration and fluid cleanliness can all influence mechanical-seal performance. Problems elsewhere in the pump or process can eventually appear as seal problems.

This is particularly important in Oil & Gas applications, where pumps may handle hydrocarbons and other demanding process fluids under elevated pressure and temperature.

A seal can therefore fail even when the replacement seal itself is not defective.

One of the most serious operating mistakes is allowing the mechanical seal faces to run without the liquid or controlled environment required by the seal design.

This can happen when:

• The pump is started without being properly filled.
• The seal chamber is not adequately vented.
• Flush flow is interrupted.
• Cooling is insufficient.
• Seal piping becomes blocked.
• A valve in the seal-support system is incorrectly positioned.
• The process condition causes vaporization around the seal faces.
• The pump operates outside its intended conditions.

Manufacturer instructions specifically warn that dry running can cause overheating and damage to sealing surfaces, resulting in excessive leakage or greatly shortened seal life.

What happens during dry running?

In simple terms:

Loss of lubrication → increased friction → heat generation → face damage → leakage → seal failure

The exact failure mechanism depends on the seal design and application, but the basic lesson is clear:

Don’t treat the seal environment as an afterthought.

In an Oil & Gas facility, mechanical-seal reliability is not only about replacing a worn component.

A seal may be controlling leakage from equipment handling hydrocarbons or other hazardous process fluids. API 682 provides a structured framework for specifying and applying mechanical seal systems in petroleum, natural-gas and chemical applications, with objectives including reliability and operational safety.

This is why the seal, pump, process conditions and seal-support system should be considered together.

For example, depending on the application, engineers may need to consider:

• Single or dual seal arrangement
• Seal chamber conditions
• Flush arrangement
• Barrier or buffer system
• Cooling requirements
• Pressure
• Temperature
• Fluid properties
• Vaporization tendency
• Solids or contaminants
• Pump speed
• Shaft movement and vibration

The correct configuration depends on the actual application—not simply the name of the industry.

If a pump seal is experiencing any of these conditions, investigate the operating environment before simply installing another replacement seal.

1. Repeated seal leakage

If the same pump repeatedly develops leakage after seal replacement, the underlying operating condition should be investigated.

Repeated replacement without root-cause analysis can simply repeat the same failure.

2. Abnormally high seal temperature

High temperature around the seal can indicate inadequate cooling, insufficient circulation or another operating problem.

For example, Flowserve’s seal-support documentation identifies insufficient cooling-fluid supply, insufficient cooling-fluid temperature and clogged cooling components as possible causes of elevated temperature in a seal system.

3. Flush or barrier system pressure/flow problems

A seal-support system cannot perform its intended function if its supply is unavailable, restricted or incorrectly controlled.

Flowserve troubleshooting guidance, for example, lists failed flush/barrier supply, closed isolation valves and blocked interconnecting piping among conditions that can affect seal-support performance.

4. Sudden change in operating conditions

A seal selected for one operating window may experience problems when process conditions change.

Changes in:

• Pressure
• Temperature
• Fluid composition
• Pump speed
• Flow conditions

can alter the environment around the seal.

5. Unusual noise or vibration

Vibration can affect seal-face behavior and may also indicate problems elsewhere in the rotating equipment.

That is why troubleshooting should not automatically start and finish at the seal.

Before ordering another mechanical seal, collect the actual operating information.

Pump information

• Pump manufacturer
• Pump model
• Shaft diameter
• Speed
• Pump type
• Existing seal arrangement

Process information

• Fluid/product
• Operating temperature
• Operating pressure
• Pumping conditions
• Fluid viscosity
• Presence of solids
• Vaporization characteristics

Seal information

• Existing seal type
• Seal materials
• Seal arrangement
• Seal support system
• Flush/barrier arrangement
• Previous failure mode

Operating history

Ask:

When did the seal fail?

Was it:

• During startup?
• During normal operation?
• After shutdown?
• After maintenance?
• After a process change?

This timeline can be extremely valuable when looking for the root cause.

This is one of the most important lessons for maintenance teams.

When a seal fails, there are at least two different questions:

Question 1:
What happened to the seal?

Question 2:
Why did that condition happen?

For example:

Observed failure: Excessive leakage

That is not necessarily the root cause.

The investigation may need to continue:

Leakage → damaged seal faces → overheating → inadequate cooling/flush → blocked or poorly functioning support system

The actual root cause may therefore be somewhere outside the seal itself.

A documented EagleBurgmann case illustrates this type of chain: inadequate cooling led to dry running of seal faces and subsequent seal failure after a cooling-system heat exchanger became plugged.

A practical approach is to focus on the complete sealing system, not only the replacement component.

Before startup

Check:

• Is the pump properly filled?
• Is the seal chamber properly vented?
• Are flush/cooling lines open?
• Is the required flush or barrier supply available?
• Are valves in the correct position?
• Is the equipment ready according to the pump and seal manufacturer’s instructions?

Manufacturer installation guidance specifically emphasizes checking seal recirculation/flush, heating or cooling requirements and ensuring the seal chamber is properly vented and filled with liquid.

During operation

Monitor:

• Seal leakage
• Temperature
• Pressure
• Flush/barrier conditions
• Vibration
• Process changes

After a failure

Don’t immediately dispose of the failed seal.

Inspect it.

The condition of the seal faces, O-rings, springs, sleeves and other components can provide clues about what happened.

A mechanical seal does not work in isolation.

The seal design, pump, process conditions and seal-support system all have to work together.

One of the most damaging mistakes is allowing the seal faces to operate outside the conditions required for proper lubrication and heat removal. Dry running and inadequate cooling can rapidly turn a small operating issue into seal-face damage and leakage.

So, the next time an Oil & Gas pump seal fails, don’t ask only:

Which seal should we install?

Ask:

What condition caused the previous seal to fail—and have we fixed that condition?

That question can be the difference between replacing a seal and solving a recurring reliability problem.