Challenges Faced in Maintaining an Old Water Tank
Introduction
Water Tank: Water tanks are very essential to most industries, but over time, they need periodic maintenance and inspection to be safe and efficient. This case study looks at an 18-year-old water tank that was presented for inspection. The inspection revealed critical maintenance issues, such as paint defects, rusting, and contamination. This article explores the findings, tests conducted, and corrective actions taken to restore the tank to its optimal condition.
Pre-Assessment: Understanding the Tank
It is very important that some preliminary information be taken note of before inspection of the tank: its operating temperature and details of its specifications. Unfortunately, in this case, key project documentation was missing for this specific tank. However, experience accompanied by a thorough pre-inspection analysis of the physical characteristics of the tank would complete the review.
Observations At Inspection
Exterior of the water tank was inspected and the general condition was rated as POOR based on the following conditions:
Paint Defects
- Paint peeling and chalking were observed. Probably, due to the age.
- Rust stains were seeping from various places.
Contamination
- Greasy dust with oil was noticed all over many places majorly in the valve operating areas.
Rusting
- Rust spot and pinpoint spotting was noticed at various sites.
Tests Conducted on the Water Tank
The tests conducted were as follows, in order to measure the extent of damage and therefore identify the appropriate method for repair.
Coating Thickness Measurement:
Coating thickness ranged from 150 to 260 microns
Identification of Coating System
3-coat system with Zinc-Rich Epoxy, Polyamide Epoxy, and Polyurethane coating system on the tank
Rust Evaluation: ASTM D 610-01
Rust was present at scattered areas, and it occupied from 16% to 33% of the painted surface area.
Cross-Cut Adhesion Test (ASTM D 3359 Method A):
Primer adhesion was good in most cases, but topcoat was poor in some sections
MEK Rub Test
The test confirmed degradation at some places.
Failure Causes
The primary cause for the deteriorating condition of the tank was failure to service it regularly. The corrosive environmental factors such as moisture, grease, and dust had led to corroding and damage to paints over time.
Corrective Actions Recommended
To rejuvenate the tank and continue operating it for a longer duration, the following actions are recommended:
Surface Preparation
Clean the tank thoroughly through high-pressure water washing and degreaser.
Repair Damage:
Blast on damaged area to remove rust and dirt.
Apply the existing 3-coat paint system; ensure proper curing is made at each stage
Approvals and Safety
Always present the repair process prior to implementation.
Make sure that all activities were well within the HSE limits.
Future Maintenance Plan:
In the future, periodic check-ups and maintenance work for the same issue from resurfacing again.
Conclusion
Generally, proper maintenance and inspection of a water tank could be regarded as one of the ways to prolong the existence of a water tank. In this case study, attention is focused on early warning signs such as peeling paint and rusting which are likely to prevent the repair cost later. When corrective measures and safety standards are adhered to, then this 18-year-old tank could regain functionality and durability.
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