Sensible Pressure Vessel and Above Ground Storage Tank Maintenance Selection

Statutory equipment maintenance is best done in accordance with stipulated international standards so you have clear evidence that the appropriate maintenance was done to industry accepted practices and requirements.



Hello Mike,

What do you think is the best way to set a strong plan for 5 year cycle Test and Inspection of refinery process units such as FCC, Crude units, etc. and for above ground Storage Tank Test and Inspection period 10 or 20 years cycles?



Hello Friend,

Thank you for making contact.

You need to use recognised international standards when it comes to doing the maintenance of pressure vessels and pressure equipment. The one we use in Australia is AS 3873 Pressure Equipment-Operation and Maintenance and its complementary standard AS 3788 Pressure Equipment-In-service Inspection. There are equivalent American and European codes too, like API 510 Pressure Vessel Inspection Code and EN 13445 Unfired Pressure Vessels.

You will have to meet the regulatory safety requirements that apply in your country and you use the standards to identify what actions will satisfy your laws and regulations. In addition, these standards contain information on the specific maintenance activities to do for the particular type of equipment they cover.

The standards also specify the recommended inspection and maintenance cycles and the various tests and inspections to perform at each scheduled inspection.

Remember that these standards are the collection of years of experience and contain the knowledge and advice of many specialist people. It is in your best interest to read them and follow their requirements.

Many companies try to cut vessel and tank inspection costs so low that they make their plant and its operation unsafe. You do maintenance to protect against disasters. If you cut-out maintenance test and inspection activities you increase your risks of unknown failures and unwanted calamity. The best advice is to run the plant properly (never above design conditions) and stably (with no surging flows, no surging temperatures and no surging pressures) to minimise its degradation and do the minimum number of necessary maintenance inspections when due to be sure the equipment will be safe until the next inspection.

If you want to do something smarter than just following the pressure equipment standard then use the Risk Based Inspection approach of API580 Risk Based Inspection to minimise the maintenance that you must do on pressure vessels. It was designed to minimise the cost of pressure equipment inspections while ensuring the plant remains safe.

One other smart thing that you can do is to make sure that you keep thorough and complete records of the equipment operation and maintenance history. If you ever chose to extend the inspection periods the regulatory body will only give you permission to increase the maintenance cycle time if you can prove the vessels and tanks are in excellent condition and the past maintenance work was done to best practice.

One more smart practice that will save you money is to manage the maintenance outage very tightly. Find all the possible ways to minimise the duration of your pressure vessel maintenance inspection outages and above ground tank inspection shutdowns. You do that by planning the outages in full detail, activity by activity, and then identifying from the list of work those tasks that can only be done during a shutdown and those that can be done without shutting down the vessel or tank. Do the work that does not need a shutdown outside of the outage. You maybe able to save several days stoppage time by limiting the shutdown work to those jobs that can only be done when the vessel or tank is taken off-line.

I hope that this information will help you select the appropriate maintenance and cycle for your pressure equipment and atmospheric storage tanks.


My best regards to you,

Mike Sondalini
Managing Director
Lifetime Reliability Solutions HQ


PS. If you require advice or input on maintenance engineering questions please feel free to contact me by email at