Comprehensive Liquid Storage Tank Inspection Service for Global Industrial Compliance
As an ISO/IEC 17025 accredited laboratory, we deliver a rigorous liquid storage tank inspection service that verifies structural integrity, pressure containment, corrosion protection, material quality, and long-term operational safety of aboveground and underground storage tanks. Our liquid storage tank inspection service supports manufacturers, terminal operators, and exporters who must demonstrate conformity to API 650, API 620, EN 14015, AWWA D100, and regional pressure equipment directives across the European Union, North America, the Middle East, and Asia. Every inspection is performed under our CNAS-accredited quality system, producing reports accepted by notified bodies, insurers, and procurement authorities worldwide.
Product Samples We Regularly Test Under Our Liquid Storage Tank Inspection Service
- Aboveground welded steel storage tanks — for crude oil, refined fuels, chemicals, and water, built to API 650 or EN 14015
- Stainless steel and high-alloy storage tanks — for corrosive chemicals, food-grade liquids, and pharmaceutical intermediates
- Fiberglass reinforced plastic and thermoplastic tanks — for acids, alkalis, and high-purity process fluids
- Double-wall and underground storage tanks — with leak detection and cathodic protection systems for fuel stations and chemical terminals
- Rectangular and shop-fabricated small tanks — for lube oil, diesel, and process water storage
- Pressure vessels and spherical tanks for liquefied gases — for LPG, ammonia, and other pressurized liquids
- Rubber-lined, glass-lined, and coated tanks — for aggressive media requiring internal corrosion barriers
Steel and Alloy Liquid Storage Tank Inspection
- Optical emission spectrometry for alloy verification per ASTM E415 and ISO 14284 — the chemical composition of shell plates, bottom plates, and roof plates is analyzed to confirm grades such as A36, A283, A537, or 304/316 stainless steel, preventing material substitution and ensuring weldability and corrosion resistance.
- Ultrasonic thickness mapping of shell rings and bottom plates per ASTM E797 — automated ultrasonic scanning measures remaining wall thickness at multiple grid points to detect general corrosion, pitting, and local thinning that could compromise the tank's pressure-holding capacity.
- Magnetic particle inspection of welds and high-stress zones per ISO 17638 and ASTM E709 — surface-breaking cracks, lack of fusion, and fatigue damage at shell-to-bottom, nozzle, and roof junctions are revealed using fluorescent magnetic particles.
- Radiographic testing of full-penetration welds per ISO 17636-1 and ASME BPVC Section V — new and repaired welds are examined for internal porosity, slag inclusions, and incomplete penetration using X-ray or gamma radiography with acceptance to API 650 or customer specifications.
- Vacuum box testing of bottom lap welds and corner welds per ASTM E1004 — a soap solution is applied over the weld and a vacuum box is placed on top, detecting any through-thickness leaks that would allow product loss or soil contamination.
- Hydrostatic testing of the complete tank per API 650 and EN 14015 — the tank is filled with water to the maximum design level and held for a specified duration while settlement, deformation, and leakage are monitored to verify the structural integrity of the shell and foundation.
- Pneumatic testing of roof and attachments for low-pressure tanks per API 620 — a controlled air pressure is applied to verify the tightness of the roof, nozzles, and flanged connections without overstressing the shell.
Stainless Steel and Corrosion-Resistant Tank Inspection
- Ferrite content measurement in austenitic and duplex stainless steel welds per ISO 8249 — the delta ferrite number is quantified on weld metal and heat-affected zones to ensure the microstructure resists hot cracking and chloride stress corrosion cracking in aggressive liquid service.
- Intergranular corrosion testing per ASTM A262 Practice C or E and ISO 3651-2 — welded specimens are boiled in acid solutions to detect chromium carbide precipitation and verify that the tank material resists sensitization in acidic and high-temperature process environments.
- Pitting and crevice corrosion resistance per ASTM G48 Method A — the tank material is exposed to ferric chloride solution at defined temperatures to determine the critical pitting temperature and to confirm resistance to localized corrosion in chloride-containing stored liquids.
- Passivation verification per ASTM A967 and ASTM A380 — copper sulfate and ferroxyl spot tests confirm that the passive chromium oxide layer is intact on all wetted surfaces after fabrication, welding, and cleaning, preventing contamination of high-purity liquids.
- Cleanliness and surface roughness inspection per ASME BPE and ISO 4287 — the internal surfaces of sanitary and pharmaceutical tanks are profiled to verify the specified Ra value and to ensure no crevices, pits, or weld defects harbor bacteria or product residue.
- Riboflavin and dye penetration testing of spray ball coverage — for CIP tanks, a fluorescent dye is sprayed inside the vessel and inspected under UV light to verify complete coverage of all internal surfaces by the cleaning system.
Fiberglass Reinforced Plastic and Thermoplastic Tank Inspection
- Barcol hardness and cure verification per ASTM D2583 — the hardness of the FRP laminate is measured to confirm complete resin cure, which directly influences the chemical resistance and mechanical strength of the tank wall.
- Ultrasonic and acoustic emission testing of FRP tanks per ASTM E2580 and EN 13121 — internal delamination, voids, and fiber/resin ratio variations are detected to ensure the laminate is free from structural defects that could lead to sudden failure.
- Thickness mapping and laminate schedule verification — the wall thickness at each laminate layer is measured with ultrasonic and destructive core sampling to confirm the tank was built to the specified laminate schedule for the design pressure and chemical service.
- Internal pressure and vacuum testing per BS 4994 and EN 13121 — the tank is pressurized and subjected to vacuum to verify the shell and joints maintain structural integrity and leak tightness under the maximum design conditions.
- Chemical resistance testing of the resin and liner per ASTM C581 — laminate coupons are immersed in the stored chemical at service temperature and the change in hardness, weight, and appearance is measured to predict the long-term compatibility of the tank material.
- Spark testing of the internal corrosion barrier — a high-voltage spark tester scans the internal surface to detect pinholes, cracks, or thin areas in the corrosion barrier that would expose the structural laminate to chemical attack.
Underground and Double-Wall Storage Tank Inspection
- Cathodic protection effectiveness survey per NACE SP0169 and API 651 — the tank-to-soil potential is measured to verify that the impressed current or sacrificial anode system is providing adequate corrosion protection to the external surface of the underground tank.
- Leak detection system functional testing per EPA 530 and EN 13160 — the interstitial monitoring sensors, automatic tank gauging, and line leak detectors are tested to confirm they reliably detect a leak in the primary or secondary containment.
- External coating and holiday detection per ASTM D5162 — the tank coating is inspected with a holiday detector to identify pinholes and discontinuities that could allow soil-side corrosion of the tank shell.
- Structural integrity evaluation with ultrasonic B-scan and long-range guided wave testing — the tank wall is scanned to detect internal and external corrosion, pitting, and remaining wall thickness without excavation.
- Tank tightness testing by mass or volumetric method per EN 13160-2 — the tank is tested over a defined period to detect any product loss and to verify the integrity of both the primary and secondary walls.
- Soil corrosivity assessment per ASTM G57 — soil resistivity and chemical analysis are performed to evaluate the aggressiveness of the burial environment and to design the appropriate cathodic protection and coating system.
Report Recognition and ISO/IEC 17025 Compliance
Every method described within our liquid storage tank inspection service is covered by our ISO/IEC 17025 scope of accreditation. Our inspection reports are accepted by European notified bodies for pressure equipment and storage tank compliance, by North American API and EPA authorized inspectors, and by customs and regulatory authorities across the Middle East, Australia, and Asia. Whether you need a complete new tank fabrication inspection, an in-service fitness-for-service assessment, or a root cause failure analysis of a storage tank incident, our laboratory delivers the measurement accuracy and industrial expertise that global supply chains demand.
