May 15, 2006
Rust, wear, and dirt cost tube fabricators and producers millions of dollars annually, and they can be the bane of tube processes. Analyzing the criteria for selecting the lubricant, cleaner, and rust preventative can help provide maximum protection.
This guide is part of an article series "Flushing out four-letter words-rust, dirt, and wear; Part II: Removing soils effectively," by Mike Pelham, International Chemical Co., Philadelphia, reprinted from the June 2006 issue of The Tube & Pipe Journal®. The article addresses how to eliminate tube producing and fabricating problems related to dirt, rust, and wear. To read the article series online, enter "Pelham" in thefabricator.com search field.
|Plugged spray nozzles resulting in poor coverage.|
Insufficient coverage and inadequate direction of cleaner solution.
|Inspect and clean nozzles; clean and descale washer if necessary.|
|Low pump pressure or damaged pump impeller.||Check, repair or replace impeller; adjust pump pressure.|
|Excessive foam.||See Foam section.||Chemical|
|Incorrect cleaner solution.||Adjust concentration to manufacturer's recommendation.|
|Cleaning temperature too low.||Increase temperature.|
|Change in soils being cleaned; a new lubricant or coolant may not be effectively removed with the existing cleaner or at the current temperature.||Evaluate cleaner and adjust temperature to manufacturer's recommendation; monitor cycle times.|
|Air leaks in the piping to the pump inlet or in the pump itself, causing aeration and/or cavitation of the cleaner solution resulting in excessive foaming.||Find the leak and seal it; check all hose clamps for tightness.|
|Sump level is below pump intake level which causes aeration and subsequent foaming.||Raise solution to correct level.||Chemical|
|Incorrect cleaner concentration.||Adjust concentration to manufacturer's recommendation.|
|Incorrect cleaner temperature.||Adjust temperature accordingly.|
|Cleaner solution contaminated with a foreign material.||Use a defoamer as a short-term solution, then identify the source of contamination. For a one-time occurrence, dump and recharge washer; if foam changes continually, change cleaning product.|
|Streaking or Spotting||Mechanical|
|Part configuration causes uneven coating, resulting in uneven washing.||Insert or adjust air blowoff.|
Tilt parts to facilitate runoff of excess solution.
|Rinse nozzles misaligned.||Adjust nozzles.|
|Rinse temperature and/or cleaner temperature too high, causing flash drying or cleaner breakdown.||Adjust temperature to manufacturer's recommendation.||Chemical|
|Cleaner concentration elevated in the rinse because of excess carryover (flowover) of cleaner on the parts or overspray running into rinse tank.g||
Tilt parts to facilitate runoff of excess solution.|
Adjust nozzle direction to eliminate overspray.
|Cleaner cannot be removed effectively.||Change to a nonsilicated cleaner.|
Check for soils in bath.
Consult with cleaner manufacturer.
|Temperature too high, causing detergent to dry on parts.||Adjust temperature to manufacturer's recommendation.|
|Parts don't dry.||See Wet Parts section of this guide.|
|Rust on Cleaned Parts||Mechanical|
|Rust-protective film rinsed from the workpieces by fresh water.||Adjust concentration to manufacturer's recommendation.|
|Parts rusted before entering the washer.||Inspect parts before washing. If rust is present, determine its origin.|
|Parts not clean.||See Poor Cleaning section of this guide.|
|Work left in the washer over a shutdown period||Verify wash cycle is finished and washer is empty before shutdown.|
Keep washer doors open to reduce humidity.
|Contact between parts.||Separate parts.|
Use a water-displacing rust prevention agent.
|Wet parts.||See Wet Parts section of this guide.||Chemical|
|Incorrect cleaner concentration||Adjust concentration to manufacturer's recommendation.|
|Cleaner not appropriate for the application.||Consult the manufacturer to select a cleaner that matches the soils.|
|Air blowoff nozzles out of alignment.||Adjust direction and temperature of air blowoff nozzles.|
|Rinse temperature too low.||Adjust temperature to manufacturer's recommendation.|
|Conveyor speed too fast.||Adjust conveyor speed.|
Increase air blowoff temperature.
Increase air blowoff volume.
|Hard Water||Cleaner not compatible with water's mineral concentration.||Change to a cleaner compatible with hard water.|
Use softened or deionized water in the rinse stage.
Use a rinse aid.