Case History

50% time reduction for pre-inspection cleaning in sour water tank


Our large industrial facility client needed their sour water tank cleaned and drained prior to an upcoming inspection


We added a mixture of FQE H2S Scavenger, Pyrophoric, Ammonia Odor, and LEL-Surface chemicals into residual liquid for cleaning


Utilizing our chemicals saved on costs due to faster execution of the project
50% reduction in cleaning time compared to potassium permanganate
Neutralized the hydrogen sulfide, and iron sulfides in the tank


FQE H2S Scavenger
FQE Ammonia Odor
FQE LEL-Surface
FQE Pyrophoric

FQE’s solution to faster pre-inspection cleaning

Our large industrial facility client needed two sour water tanks cleaned and drained before an upcoming inspection. The tanks, which had been in operation for several years, accumulated a significant amount of sludge and other contaminants that needed to be removed to bring the tanks into compliance for entry and inspection.

Tank 1 was 38 ft. in diameter with 2 ft. of sludge and 1 ft. of water. Tank 2 was 42.5 ft. in diameter and contained 1 ft. of sludge and 2 ft. of water. Tanks were treated back-to-back.

The process

The client pumped down contents until the 3 ft. level was reached. The contractor used a temporary pump to begin the circulation of the residual liquid in the tank bottom. FQE Chemicals were added into the pump suction during the circulation. The tanks’ contents were circulated until testing showed zero LEL, zero H2S, and zero ammonia odor; no form of vapor control was used or needed. Once the readings reached zero, the liquid was pumped to the site’s oily water sewer.

Firewater with diluted FQE Chemicals was used for a final rinse; no contaminants were noted during the flushing operation. The tanks were entered without the need for respiratory protection, and low volumes of non-reactive solids were removed for subsequent handling. Both tanks were completed in less than two shifts each.

Guaranteed satisfaction

The results using our sulfide custom chemistries were impressive. First, we neutralized the hydrogen and iron sulfide contents with our FQE H2S Scavenger and Pyrophoric products and achieved a 50% reduction in cleaning time compared to the traditional method, potassium permanganate. Lastly, we degassed the tanks with our LEL Surface product.

This was a significant improvement for our client and allowed them to pass their inspection easily. Overall, our FQE products proved to be an effective and efficient solution for cleaning and bringing our client’s sour water tank into compliance.


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