Fluid Sampling Procedure
Purpose: To obtain a fluid sample for assessment of the contamination level in a manner that minimizes the possibility of introducing additional contamination or distortion during the collection process which could skew the fluid analysis results.
Note: Due to the relatively small volume of fluid being extracted for the test (compared to the size of the overall system fluid volume), even the smallest amount of contamination introduced into the sample from a source outside the system (such as off of a valve stem at the sample port) can inflate the contamination level observed by the analytical lab compared to the true level, thereby rendering the lab results incorrect.
Materials Needed
a. Ultra-clean sample bottle(s). (One for each sample, usually provided by the analytical
lab handling the analysis)
b. Data sheet for each sample that details the fluid involved (e.g., fluid name, operating
temperature, age of fluid, etc.), as well as the company identifier for equipment in which
the fluid operates (form usually provided with the sample bottles from the analytical lab
conducting the fluid test).
c. Suitably sized container for the purge volume of fluid generated during the sampling
procedure (typically a one to five gallon bucket).
d. Appropriate cleaning rags for wiping sample bottle surfaces (e.g., oil absorbent
sheets or pads).
e. Permanent black marker to label sample bottles (or printed bottle label with sample
ID number that matches ID number of the data sheet, as per step 1.b).
f. Tape for locking sample bottle cap in place and to protect markings on sample bottle.
Procedure Instructions
a. Mark the sample bottle with permanent marker with sample ID number and any other
appropriate information. Then, wrap the bottle with tape to protect the writing and
minimize erosion of the marking by the fluid being sampled.
b. Place the purge container under the sample valve port and open the sample valve
until a small, yet steady stream of fluid is established. Once flow is established, do not
shut off or adjust the valve for the duration of the sample extraction.
c. Uncap sample bottle and fill ¼ full of fluid. Then, recap and shake vigorously for three
seconds. Uncap sample bottle, drain into purge container, and then repeat this step two
more times (three total bottle flushes).
d. Fill the sample bottle ¾ full and cap bottle.
e. Tighten cap on the sample bottle, then tape cap in position to minimize chance of cap
unscrewing during shipment to analytical lab.
f. Repeat procedure for each fluid sample to be taken.
