Operation and Maintenance of Bolted Steel Tanks: Tips and Techniques

Bolted steel tanks are used for a variety of industrial storage needs including water, sand, mud, waste materials, liquid food products, etc. With the use of appropriate gaskets and fasteners, this type of tank can be used to store virtually any kind of material. It is you who will be operating the tank. And you will know what type of material will be stored. Just like any other tangible asset, bolted steel tanks also undergo wear and tear. But you can extend the lifetime of the tank through an appropriate maintenance program. The nature of operation and maintenance will vary according to the type of tank and the thing you store. However, here are tips and techniques that can be applied to the majority of tanks.


Inspect The Site

Accumulation of soil and debris is very usual in any industrial setting. Check the exterior of the tank periodically and remove any debris particularly which is in contact with the tank shell, floor, or appurtenances. Ensure to prevent soil and water accumulation at the chimes or horizontal joints. Soil can erode the joints and lead to termination of warranty for your tank.

Check The Foundation

If the foundation is made of concrete ring wall and slab, check for any fracture and distortion annually. Any such defect may cause eccentric loadings on the tank and ultimately failure of the storage system. Also, make sure there are no gaps or fissures between the tank bottom and foundation as the foundation settles down.

However, if the foundation is made on the granular berm, make sure there is no wash-out under the grade band. Maintain adequate water drainage away from the tank. Also, do not allow vegetation or tree growth within several yards of the tank.

Tank Inspection

Shell seams are the most important structures of your tank. Inspect those monthly for a few months and three to six monthly thereafter. The first thing to look for is any distortion on the seams. It may occur as a result of improper handling or undue stress by the stored material. Inform your contractor immediately. Although leaks are less common for bolted tanks, they are not rare. If there is any leak, it should be obvious during the inspection. Check tightness of all nearby bolts if such thing happens. To prevent future leaks, check the tightness of bolts randomly at all seams. Clean any foreign material attached to the tank shell like mud, oil, debris, etc. Find out how to make the most of your tank at

Check the tank roof once or twice a year for any foreign material that might have been left by workers. If left for a long time, it may cause rust to form or create a hole in the roof.

Check For Exterior Corrosion

The exterior tank coating will usually work fine in the first year of service. After that, you should periodically examine the coating. The cost of repair to the coating system may be borne by you or the manufacturer depending on the contract.

Check For Interior Corrosion

Have a routine check in the interior of the tank. For this, you have to drain the tank first. If it is not possible, an expert diver may perform the inspection. Interior coating may not be properly seen due to the accumulation of sediment. In that case, drain the tank, clear the sediment, and do the necessary repair. Repeat the inspection every three to four years. Usually, the customer bears the cost of this kind of inspection and repair.

Servicing Of Appurtenances

For thief hatches annually inspect and clean the seat ring and gasket. Ensure all valves are functioning. In case of cold climates, prevent icing due to condensation of fluids. Regularly clean screen and replace it if damaged severely.

Inspect the screen of free-flowing vents yearly or so. Clean any dust and debris that might accumulate on it. Icing may obstruct the screen in the winter season. Keep an eye on it and replace the screen if it is no longer usable.

Check if the nozzles and connecting pipes are aligned properly and not causing distortion of tank wall at the sites of attachment. Adjust the pipe supports as required to prevent this distortion.

You might want to conduct visual and electrical tests to ensure proper functioning of the other parts of the tank system that are not mentioned in this article. There is no alternative to a good inspection to enjoy a smooth operation of the tank in the coming years.

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