Tips for NDT Drying Cycles and How to Get the Best Results

By: Publisher Team | Nov 28, 2020 19:11 PM
Tips for NDT Drying Cycles and How to Get the Best Results

Importance of Correctly Drying Parts 

Proper drying of parts allows the uniform application of dry powder developer and nonaqueous developer for the best inspection results. Slightly damp parts or pooled water areas will inhibit the developer application and possibly cause areas of incomplete developer coverage. Water-soluble and water-suspensible developers also require the correct drying of the test parts after applying the developer to prevent streaking and running of the developer coating. 


Note: Flowchart shows parts being dried before dry powder and nonaqueous developer, but dried after water-soluble and water suspendable developer.

Optimal Drying Conditions 

For best results, parts should be dried in a forced air circulating oven before application of dry powder and nonaqueous developer and after application of water soluble or water suspendible developer.

Developer Options

ZP-4B 

Dry powder developer (Form a) for Type 1 fluorescent penetrant testing

  • QPL SAE AMS 2644 
  • Pratt & Whitney approved 


ZP-9F

Solvent-based developer (Form d, Form e) for Type 1 fluorescent and Type 2 visible penetrant testing 

  • QPL SAE AMS 2644 
  • Pratt & Whitney approved 


ZP-14A 

Water-soluble developer (Form b) for Type 1 fluorescent penetrant testing 

  • QPL SAE AMS 2644 approved 


ZP-5B 

Water suspendable developer (Form c) for Type 1 fluorescent and Type 2 visible penetrant testing 

  • QPL SAE AMS 2644 approved 

5 Tips for Drying Liquid Penetrant Test Parts 

  1. An oven temperature range of 140 – 145 ⁰F (60 – 63 ⁰C) is suggested. The maximum oven temperature is 160 ⁰F (71 ⁰C) for fluorescent penetrant inspection systems. 
  2. If permitted by governing specifications, low-pressure air blow-off (5 psi or less) may be used to remove excess water from parts before placing parts in the oven.  
  3. Place parts in the oven for optimum airflow. Do not crowd parts. 
  4. Do not place parts with pooled water in the oven. 
  5. Remove parts from the oven as soon as they are dry.  

Learn about the available properties of developers and the relationship between dwell time and inspection quality here

Blog By:  Cheri Stockhausen, Product Applications Manager 

Source:  Tips for NDT Drying Cycles and How to Get the Best Results (magnaflux.com)


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