Bulk Petroleum Tank Cleaning Verification

[JacobHarris]

The government wants an independant method to prove several tanks (200 mblls each) are clean before they are turned over to another agency. API 1404 recommends using a handheld LEL meter to determine vapor content, but this is not objective or quantitative. My two questions are...

1. Is there a regulation or industry standard that correlates quantitative air sampling to tank cleanliness?

2. Is there an alternative sampling practise or approach that can be used to independently verify a tank is clean? (other than visual inspection by the government)

 

[unclesyd]

There are several methods that maybe used.

What is the definition of clean you hope to achieve or what are your your requirements for claen tank?
What were the previous materials in the tanks?

This information will help.