Zerust Zerion® FVS as a Corrosion Inhibitor After Hydrotesting

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Zerust Zerion® FVS as a Corrosion Inhibitor After Hydrotesting

Experience has shown that residual water often remains within the vessel after drying resulting in corrosion.

Hydrotesting is used extensively to test vessels such as pipelines, pressure vessels, heat exchangers, etc., for strength and leaks. Typically, the test involves filling the vessel with water to a specified test pressure. Once the test is complete, the water is drained, and the vessel is dried. Experience has shown that residual water often remains within the vessel after drying resulting in corrosion. This report will provide data that highlights the effectiveness of  Zerust Zerion® FVS as a corrosion inhibitor to provide corrosion protection during the hydrotest period and from residual hydrotest water.

Experimental

Three tests were run to evaluate the performance of the inhibitor:

  1. Test 1: Immersion (qualitative and quantitative)
  2. Test 2: Residue Layup (qualitative)
  3. Test 3: Multiphase (qualitative)

A brief outline for each of the tests is shown below along with the results.


Test 1: Immersion

Immersion Test Set-up

Figure 1 – Immersion Test Set-up

SET-UP – Immersion Test

  1. Panel assembly created
  2. Panel assembly and test solution added to jar (tap water)
  3. Samples aged for 12-13 days @ 50° C
  4. Corrosion products stripped from panels per ASTM G1
  5. Inhibitor efficiency calculated

 

RESULTS – Immersion Test

A picture of the jars after removal from the oven in shown below.

 

Inhibitor Concentration Immersion Test Results

 

 

 

 

 

 

 

 

 

 

 

RESULT NOTES – Immersion Test

A high level of corrosion products can be seen in the control samples, (no inhibitor).  The samples with inhibitor show low levels of corrosion products.

The panels were stripped per ASTM G1 and a summary of the inhibitor efficiency is shown below in Table 1 and graphed below.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Test 2: Residue Layup

 

SET-UP – Residue Layup

  1. Steel panel bent into a V shape
  2. Panel placed into jar
  3. Test solution added to jar (tap water)
  4. Jars sealed closed and aged for 24 hours @ 50° C
  5. Panel removed from jar and solution poured from jar
  6. Panel placed back into jar and sealed closed
  7. Jars aged for 7 days @ 50° C

Note: A green dye was added to the solution as a visual aid.

Figure 2 - Residue Layup Test Set-up

Figure 2 – Residue Layup Test Set-up

 

 

 

 

 

 

 

 

 

RESULTS – Residue Layup

A picture of the panels after aging is shown below.

Residue Layup Test Results

 

 

 

RESULT NOTES – Residue Layup

The protected samples (with inhibitor), exhibit a significant reduction in corrosion versus the control.


Test 3: Multiphase

 

SET-UP – Multiphase

  1. Steel panel bent into a V shape
  2. Panel placed into jar
  3. Test solution added to jar (tap water)
  4. Jar sealed closed and aged for 7 days @ 50° C

 

RESULTS – Multiphase

Pictures of the Multiphase samples after aging, in the jar and out, are shown below.

Multiphase Panels and Jars

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RESULT NOTES – Multiphase

The panels are evaluated in three areas: immersion, water line and airspace.  High levels of corrosion are apparent for the control samples in immersion and at the water line.  Low levels of corrosion are apparent in airspace close to the water line.  For the protected samples, a few corrosion spots are seen in the immersion area for the 0.1-0.3% inhibitor samples.  No corrosion is apparent at the water line or in airspace for any of the protected panels.


Conclusion

Experience has shown that residual water often remains within the vessel after hydrotesting and the subsequent drying resulting in corrosion. This testing showed that the corrosion inhibitor would offer a significant reduction in corrosion from both the “raw” hydrotest water and from the residual hydrotest water after drying.


Zerust Corrosion Solutions for Pipeline Preservation Post Hydrotesting

For more information about Zerust Oil & Gas Corrosion Mitigation Solutions for Pipeline Preservation Post Hydrotesting, please click here

 


Our Team is Here to Help

The staff at Zerust Oil & Gas are here to custom design a corrosion mitigation solution that is specific to your given asset. Contact us today to find out how we can help extend the life of your equipment.


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