The mechanical core of Malaysia’s heavy industries and those abroad is the pressure vessels and storage tanks. These assets can be found in oil and gas refineries, petrochemical plants, and power generation plants and are subject to extreme pressures, temperature variations, and highly corrosive environments.

Regular inspection and testing are not only advisable to provide safety to personnel and the environment, but also a federal regulation. With the help of the latest Non-Destructive Testing (NDT) and adherence to internationally accepted standards, organizations have the opportunity to identify defects in a timely manner, avoid disastrous failures, and prolong the service life of their key assets without interrupting the production process.

Understanding Pressure Vessels and Storage Tanks

The importance of these two important asset classes is to be differentiated before venturing into inspection protocols.

What Is a Pressure Vessel?

A pressure vessel is a closed container that is designed to contain gases or liquids at a pressure that is very different from the ambient air pressure. A failure can be explosive due to the energy that is stored in it. Examples of common industries are:

• Boilers: to make power/process steam.
• Heat Exchangers: The exchange of heat between liquids.
• Reactors & Separators: Separating chemical products and petroleum.

What Are Storage Tanks?

Storage tanks are intended to contain huge amounts of fluids in the atmosphere or at low pressure crude oil, chemicals, or fuels. Above-ground storage tanks (ASTs) are used in most industry facilities and they demand special foundations and secondary containment systems in order to avoid contamination of the environment.

Why Inspection is Critical for Asset Integrity

Surveys of pressure vessels and storage tanks conducted regularly have become a roadmap to safe operations:

• Early Defect Detection: The localized corrosion, wall thinning, and fatigue cracks are detected before the containment wall is violated.
• Regulatory Compliance: Compliance with the strict legal standards of DOSH (Malaysia), ASME, API, and ISO standards.
• Catastrophe Prevention: Leak, fire, or explosion causing accidental shutdown and environmental catastrophes prevention.
• Data-Driven Life Assessment: Giving the precise measurements required in Fitness-for-Service (FFS) measurements.

Common Inspection & Testing Methods

We will apply a multi-layered method to ensure the good health of your vessels and tanks.

1. Non-Destructive Testing (NDT)

NDT services enable us to have a glimpse of the metal without destroying the property. It is the gold standard of in-service equipment. Techniques include:

• UT Ultrasonic Testing (UT): Accurate measurement of thickness to monitor metal loss.
• Magnetic Particle Testing (MPT): Detecting cracks in welds that are surface-breaking.
• Dye Penetrant Testing (DPT): This process is used to find leaks and pores in non-magnetic alloys.

2. Advanced Ultrasonic Solutions

We use the method of Phased Array Ultrasonic Testing (PAUT), which provides high-resolution corrosion mapping so that asset owners can view a 3D profile of the interior wall of their tank or vessel.

3. Hydrostatic Testing

Hydrostatic testing is done after repairs or alterations, whereby the vessel is filled with liquid (usually water) and pressurized in order to check the structural limit of the vessel.

Above-Ground Inspection Scope

Notable: All pressure vessels and storage tanks inspection and testing services are performed on above-ground and onshore equipment only. No submerged or underwater and subsea inspection service.

Standards & Codes for Compliance

To make inspection findings legitimate to insurance and regulatory audit, all the work is undertaken as per:

• API 510: Pressure Vessel Inspection Code (In-service).
• API 653: Tank Inspection, Repair, Alteration, and Reconstruction.
• API 650: Welded Tanks for Oil Storage (Design and Fabrication).
• ASME Section VIII: Rules for Construction of Pressure Vessels.

Asset Integrity & Life Assessment

The final aim of pressure vessel inspection and storage tanks is to find out the maximum duration of time they can work safely.

• Remaining Life Assessment: The remaining life assessment is calculated by examining the time-dependent corrosion rates so that we can determine when a vessel will have reached its retirement thickness, and thus it will be time to perform some maintenance or replace it.
• Fitness-for-Service (FFS): This is an engineering-based test that is used to determine whether a damaged ship can safely operate at its usual pressure or at a pressure that is lower.
• Risk-Based Inspection (RBI): We give you a priority on what you maintain, so that we inspect those assets that have the greatest likelihood and impact of not functioning.

FAQs – Pressure Vessel and Storage Tanks

Q1: What is the main aim of a pressure vessel inspection?

Ans: To check the capability of the vessel to withstand a design pressure without breaking or spilling, and to meet the requirements of DOSH and API510.

Q2: What is the preferred frequency of above-ground storage tanks inspections?

Ans: Although internal inspections are usually conducted after every 10 to 20 years (according to API 653), external visual inspection and UT thickness gauging are to be conducted with much more frequencies.

Q3: Are you able to identify corrosion that is concealed under insulation (CUI)?

Ans: Yes. We apply some specific NDT methods, such as Pulsed Eddy Current (PEC) or Long Range UT, to identify Corrosion Under Insulation (CUI) on vessels without removing the cladding.

Q4: Do you offer subsea tank services?

Ans: No. Our business is confined to land-based and topside offshore pressure vessels and storage tanks.

Conclusion

High-value and high-risk assets are the pressure vessels and storage tanks that must be approached in a disciplined manner towards the integrity management process. A combination of certified NDT, adherence to the API and ASME codes, and active Fitness-for-Service assessment can help companies to guarantee the long-term stability of their facility.

With the help of special services for the inspection of the above-ground, you will minimize the chances of a catastrophic failure and keep your plant active and compliant.

Call A-Star Testing & Inspection to make an appointment to have your next API-certified inspection of pressure vessels and storage tanks done.