Troubleshooting Guide for Cleaners

WWW.THEFABRICATOR.COM MAY 2006

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.

 

Problem

Cause

Corrective Action

Poor Cleaning

Mechanical

Plugged spray nozzles resulting in poor coverageLow pump pressure or damaged pump impeller. Insufficient coverage and inadequate direction of cleaner solutionExcessive foam

Inspect and clean nozzles; clean and descale washer if necessary

Check, repair or replace impeller; adjust pump pressure

See Foam section

Chemical

Incorrect cleaner concentration; cleaning temperature too low

Change in soils being cleaned; a new lubricant or coolant may not be effectively removed with the existing cleaner or at the current temperature

Adjust concentration to manufacturer specs; increase temperature.

Evaluate cleaner and adjust temperature accordingly; cycle times may need to be monitored

Foam

Mechanical

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 Sump level is below pump intake level which causes aeration and subsequent foaming

Determine where the leak is and seal it; check all hose clamps for tightness

Raise solution to correct level

Chemical

Check cleaner concentration—it may be too low or high, depending on cleaner

Incorrect cleaner temperature

Contamination of cleaner solution with a foreign material

Adjust concentration to manufacturer's recommended level

Adjust temperature to manufacturer's recommendations

Use a defoamer as a short-term solution, then identify the contamination and cause of the foam. For a one-time occurrence, dump and recharge washer; if foam is continually changing, change cleaning product

Streaking or Spotting

Mechanical

Part configuration causes uneven coating; resulting in uneven washing

Rinse nozzles misaligned

Rinse temperature and/or cleaner temperature too high, causing flash drying or cleaner breakdown

Insert or adjust air blowoff; tilt or angle parts to facilitate drainoff of excess solution

Adjust and modify nozzles

Refer to manufacturers' requirements for correct temperature

Chemical

Cleaner concentration elevated in the rinse because of excess carryover / flowover of cleaner on the parts or overspray running into rinse tank

Cleaner cannot be removed effectively Cleaner or rinse temperature too high, resulting in detergent dry-on.

Parts won't dry off

Tilt parts to facilitate excess drain-off Align nozzles to eliminate over spray

Change to a nonsilicated cleaner; consult with cleaner manufacturer; check soils in bath

Adjust temperature as required; consult cleaner manufacturer

See Wet Parts section

Rusting of Cleaned Parts

Mechanical

Rust protective film rinsed from the work by fresh water

Parts rusted before entering the washer

Parts not clean

Work left in the washer over a shutdown period Contact between wet parts

Wet parts in general

Make sure cleaner concentration level per manufacturers recommendation

Verify where parts came from in process and what may be the cause

See Poor Cleaning section

Ensure washer is free of parts before shutting down; keep washer doors open to reduce humidity

Separate wet parts with dividers. A water-displacing rust preventive may be required

See Wet Parts section

Chemical

Incorrect cleaner concentration

Incorrect cleaner for nature of soils

Adjust cleaner concentration to manufacturers' required level

Consult cleaner manufacturer

Wet Parts

Mechanical

Air blowoffs out of alignment

Rinse temperature too low

Conveyor speed has increased

Adjust direction and temperature of air blowoffs

Adjust temperature to manufacturer's recommendation

If new rate is implemented, increase temperature and add or improve air blow off; consult with cleaner manufacturer

Hard Water

Cleaner not suited for use in high water-hardness; hardness or solids so high that residue remains in spite of cleaner

Change to suitable cleaner; use softened or deionized water in the rinse; use a rinse aid



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