Defining Method A(W) 

Method A(W) is a separate category for Method A penetrants and defined by AMS 2644 as a “Water Washable penetrant that contains 20% or more water by volume in its formula.” This category was added to the G revision of AMS 2644 and issued in April 2019. The current revision of AMS 2644 is H, which was issued in July 2020.  

Differences between Method A & Method A(W) 

For in use penetrant testing, Method A(W) has a different testing method and frequency for water content than Method A penetrant. The water content test is a quick weekly check for Method A(W) penetrants with the use of a refractometer.

If necessary, adjustments may be made by adding water or the Method A(W) penetrant to the tank. 

Features of Water-based Penetrants

Reliably Speed Up Inspection and Wash Processes 

• Identify bright indications with superior sensitivity and low fluorescent background interference. 

• Increase throughput and reduce costs by eliminating the developer step of inspection processes depending on procedures and requirements. 

• Rapid rinse and post inspection washing of parts thanks to excellent washability properties.  

Reduce Waste-Water Pollutants and Environmental Footprint 

• Reduce water treatment costs and discharge waste process water directly into the sewage system (depending on local regulations) due to minimal water-based contaminants. 

• Meet or exceed local discharge regulations with low Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) levels. 

• Support a healthy environment with water-based penetrants that have minimal environmental, occupational health and safety impact. 

Industry approvals  

• QPL Approval 

• ZL-425 and ZL-440 are approved and qualified to AMS 2644. 

Things to Know About Water-based Penetrants 

More frequent testing 

• Method A requires a monthly concentration test by sending it into a lab or PeneCert program, while Method AW requires a weekly concentration test with a refractometer.  

Approvals Met 

• If listed on QPL it meets the specifications for AMS 2644 as a Level I or 2 penetrant, depending on the classification. 

QPL Approval 

• ZL-425 and ZL-440 are approved and qualified to AMS 2644. 

Lower Water Treatment Costs 

• Disposal is a benefit for water-based or a deterrent for oil-based.  
• Maintenance due to the concentration of the water-base.  
• Wastewater treatments costs can be lowered. 

Application Method 

• Water-based is not suited for spray application.  
• Only referring to ZL-425 & ZL-440.  
• Typically used in emersion tanks. 

ZL-425	ZL-440
Water-based, water washable level 1 fluorescent penetrant; contains no petroleum distillates allowing direct drain disposal.	Water-based, water washable level 2 fluorescent penetrant; contains no petroleum distillates allowing direct drain disposal.
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