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Petroleum and Petrochemical Bulletin
The member companies of the International Federation of Inspection Agencies wish to clarify their
position regarding the determination of the amount of free water in an oil cargo.
Increasingly, IFIA member companies are receiving instructions from clients (or their loss control
representatives) specifying the water determination method to be used, electronic or manual, and their
preferences for the type and brand of water finding paste. Often, these preferences are unilaterally
stated, without the agreement of all concerned parties.
There are many types of water finding paste on the market and no standards organization has
designated “approved” water pastes. The inspection company is therefore required to select the most
appropriate paste to be used based upon the following considerations from existing API standards;
1. API MPMS Chapter 3.1A Tank Gauging, Section 10.1.5 - There are many brands of
water indicating pastes available that change color on contact with free water. It has been
found that, although all pastes react to free water, they may differ. This difference is
caused by the adhesion of the oil to the paste, which causes some pastes to give low or
2. API MPMS Chapter 3.1A Tank Gauging, Section 10.1.6 - The following qualities
should be known before using water pastes, since there are differences between brands:
a. Clarity of color change.
b. Ability to “shed” oil in which the paste is used.
c. Shelf life (some tend to harden shortly after opening).
d. Ease of application to the bar and ability to “grip” the bar.
e. Dense enough not to scrub off during the trip through oil.
f. Effectiveness equally in slightly alkaline, salt, fresh, or acidic water.
3. API MPMS Chapter 3.1A Tank Gauging, Section 10.1.7 - It is recommended that at all
locations the gauger apply two different pastes on the bar for each innage gauge at the
beginning of gaugi