Premature Seal Failure Troubleshooting

Premature Seal Failure Troubleshooting

Cause/Solution

 Most Common:

• Running Pump Dry
• Overheating from Excessive Bypass
• Excessive Water Temperature
• Excessive Inlet Pressure
Pumping Contaminated Water
• Scored or Cracked Plungers

  Running Pump Dry

Cause
Water passing through the pump is used to lubricate the seals. Running the pump dry will cause an excessive amount of heat between plungers and the seals, causing them to fail in a short amount of time. Never run a pump dry.

Solution
Always make sure water is getting to the pump before starting the engine. Inspect and replace all worn seals. Inspect the incoming line for obstructions or any flow restrictions.

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Overheating Cause by Excessive Bypass
 

Cause
Running the pump without washing or spraying water can put the pump into “by-pass mode.” When the pump is in by-pass mode and water is directed back to the pump inlet, excessive heat can quickly build.  (This is sometimes referred to as “heat rise.”)  Pump seals can be severely damaged due to high heat. 

Solution
Replace seals and do not run in by-pass mode for longer than 3 to 5 minutes. Add accessories such as a thermal valve or throttle controller to protect pump while it is in by-pass mode.

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Excessive Water Temperature
 

Cause
Pumps have a maximum operating temperature to protect seals and O-rings from heat damage.  High temperature will cause seals to wear at an accelerated rate.

Solution
Reduce inlet water temperature. If this is not possible, replace seal with high temperature seals that are available as pump options.  Consult the pump datasheet. 

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Excessive Inlet Pressure
 

Cause
In cases when the inlet water pressure is excessive, the clearance between the seals and plungers can become too restrictive.  The tighter the seals “squeeze” the plungers, the faster the seals will wear.

Solution
Lower inlet pressure with an inlet regulator. In some cases, Installing a pressure gauge is recommended to monitor inlet pressure.

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Abrasives in Water Supply
 

Cause
Water with abrasive is very hard on seals and causes the seals to wear quickly.

Solution

Add proper inlet filter to remove abrasives down to an acceptable level.
 
 

Scored or Cracked Plungers
 

Cause
Plungers are manufactured with extremely concentric and smooth finishes. Scored or cracked plungers produce an irregular “rough” surface finish that causes seals to wear quickly or unevenly. In extreme cases, seals may tear, resulting in seal failure. 

Solution
Inspect and replace cracked plunger(s). Inspect seals also as these may have been damaged by the irregular surface of a cracked plunger. Plungers may be replaced individually or in complete sets. 

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Location

1 Fleet Business Park
Sandy Lane
Church Crookham
FLEET, Hampshire
GU52 8BF

Call Now

T.01252 622031
F.01252 626655

Contact Us

sales@catpumps.co.uk