Wastewater Treatment Plant Tank Inspections

Robert SherbyProject DescriptionsLeave a Comment

Tank inspection technician checking shell plumbness.

Background

A wastewater treatment plant requested 27 tank inspections at their facility. The plant processes oily wastewater generated by manufacturing. The plant uses clarifier and oil storage tanks to process thousands of gallons of waste water each day. Recaimed oil is stored and processed in tanks until it can be recycled. The result is many different types of tanks requiring inspection, including:

  • Open-top steel clarifier tanks
  • Closed-top vertical steel tanks.
  • Closed-top vertical fiberglass tanks.
  • Cone-bottom steel tanks.
  • Cone-bottom fiberglass tanks.
  • Glass-lined bolted steel tanks.

Wastewater Treatment Tank Inspections

To provide the most cost-effective inspection program, TSP quoted each tank based on its size and type. Large tanks were quoted based on API-653, while smaller tanks were quoted based on SP001. Fiberglass tanks were with UltraAnalytix™ for examination of the tank shell, roof, and nozzles. TSP also included special scheduling and performance requirements requested by FCA.
TSP performed the following work for each category of tank:

  • Vertical steel tanks – Visual inspection of the tank interior and exterior. Ultrasonic thickness (UT) testing of the tank shell, roof, and floor. Magnetic flux leakage (MLF) testing of the tank floor.
  • Cone-bottom steel tanks – Visual inspection of the tank interior and exterior. Ultrasonic thickness (UT) testing of the tank shell, roof, and bottom cone.
  • Vertical fiberglass tanks – Visual inspection of the tank interior and exterior. Ultrasonic flaw detection of the tank shell, roof, and nozzles.
  • Cone-bottom fiberglass tanks – Visual inspection of the tank interior and exterior. Ultrasonic flaw detection of the tank shell, roof, and bottom cone.

In addition to integrity inspections, TSP evaluated repairs being made to one of the tanks. TSP performed the post-repair inspection for a roof replacement in addition to providing an integrity inspection on the tank floor and shell.

TSP delivered reports to the Owner for each of the tanks inspected. Reports included descriptions of visual inspection results, drawings showing the locations of flaws, a statistical analysis of shell thickness data on steel tanks or the UltraAnalytix™ Mechanical Integrity Report on fiberglass tanks, and a computation of each tank’s remaining life based on inspection data.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.