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API 650 Storage Tanks

Your Nationwide API 650 Tank Contractor

Phillips Tank & Structure has spent countless hours developing custom, proprietary business systems to quickly find cost-effective engineered solutions for your most difficult tank problems. Our experienced engineering staff and field repair crews are well-versed in welded tank codes API 650, API 653, API 620, and API 12D, and bolted tank codes AWWA D100 and D103.

API 650 is a globally recognized standard for the design, construction, and inspection of welded steel storage tanks. API 650 storage tanks are constructed of carbon steel or stainless steel, and can be designed to hold pressures from atmospheric to 2.5 psig.

Field-erected above-ground storage tanks (ASTs) generally range in size from 40,000 gallons to 5 million gallons, depending on the type of construction and the product stored. Industries where these tanks are used include oil and gas, chemical manufacturing, power generation, agriculture, food and beverage, potable water, and wastewater treatment.


Typically, Above-Ground Storage Tanks have welded steel construction with a fixed cone roof, geodesic dome, or floating roof. Depending on the usage, ASTs may also include one or more inlet nozzles, outlet nozzles, pressure relief valves, gauge systems, mixers, heating coils, diffusers, high liquid level alarms, fire foam systems, or overflows.​

Strength and Durability

The standard requires that the tanks be made from high-quality steel. Material test records provide tracability in the event that a material flaw is discovered. The tanks must be welded in accordance with strict guidelines to protect from tank leaks or rupture. Completed API 650 tanks must withstand the loads imposed by the stored liquid and the environmental loads contributed by snow, wind, or siesmic activity.

Secondary Containment

Under federal regulations, an AST that stores oil is called a "bulk storage container", and requires secondary containment such as a dike, containment curb, or catchment basin.​ The API 650 standard requires tanks to be designed and built with secondary containment systems to prevent spills and leaks.

Maintenance Tips for API 650 Storage Tanks

By implementing a preventative maintenance plan, facility managers  can minimize potential issues and extend the life of storage tanks and silos:

  • Conduct regular inspections to record wear, corrosion, and other issues.

  • Implement corrosion control measures, such as cathodic protection or protective coatings, to prevent damage to the tank's structure.

  • Monitor for Leaks. Leaks can occur due to corrosion, material failure, or damage to  the tank's structure, leading to environmental damage and safety  risks.

  • Address issues identified during an inspection promptly. All issues should be addressed as soon as possible to prevent further damage.

Key aspects of an inspection include:

  • Routine Inspections: Conducted on a regular basis (e.g., monthly, quarterly, or annually) to monitor the condition of the tank using visual checks, leak detection, and settlement monitoring.

  • In-Service Inspections: Carried out while the tank is in operation. In-service inspections may involve non-destructive tests such as ultrasonic thickness testing and magnetic particle inspection.

  • Out-of-Service Inspections: Conducted when the tank is empty. Out-of-service inspections can include detailed visual inspections, non-destructive testing, and destructive testing, such as taking samples of the tank's material for analysis.

Trusted, Responsive, Nationwide Tank Contractor

PTS has over 130 employees and specializes in designing, engineering, repairing, and constructing above-ground metal storage tanks and related structures. PTS has active projects in various industries, such as petroleum, power, chemical, and renewable fuels markets throughout the United States and the Pacific Island nations.

At PTS, our commitment to our customers shapes everything we do. We have served companies across an array of industries, handling new tanks, repairs, and modifications. Our collective methodology, industry knowledge, and exhaustive range of abilities permit us to meet one-of-a-kind needs of our customers as they react to industry expectations. We believe in good quality and on-time delivery.  We provide an excellent working relationship based on integrity and professionalism. 

PTS is your trusted tank advisor and provides The PTS Guarantee: if you find a less expensive engineered solution to your tank needs, our engineering work is free. PTS has developed custom, proprietary business systems that help it have the most accurate design drawings and competitive lead times in the industry. Also, PTS is a nationwide tank contractor that is willing and able to go anywhere, anytime to service your tank needs.

Project Profiles


Main Office

13 Talbot Ave

Braddock, PA 15104

(412) 315-7963

Houston, TX Office

4811 Cripple Creek Dr
Houston, TX 77017

(832) 900-2152

Hawaii Office

905 Kalanianaole Hwy #1601 Kailua, HI 96734

(808) 809-4200

Columbia, KY Office

3529 Wheeler Hill Rd

Columbia, KY 42728
(412) 315-7963

Signal Hill, CA Office

3106 East Willow St

Signal Hill, CA 90755
(412) 315-7963

Other Offices

Braddock, PA (Design/Engineering Office)

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