As in the case of similarities, there are quite a few differences concerning various parameters between API standard 650 and 620. Therefore, let us check some essential parameters to bring out the critical differences between the two models.  

API 650 - The configuration is specified to ground-supported bottom and open or closed Roof. To achieve this configuration, the entire tank bottom needs to be supported uniformly.

API 620 - It is flexible to any configuration are single centered. To achieve this, tanks of this type must revolve around a single vertical axis.

API 650 - Gas, oil, chemicals, water, and biofuels are all stored here. There are a majority of welded steel tanks utilized in an industry that follow API 650. You can find such tanks in refineries, pipelines, terminals, and other industrial facilities.

API 620 - API 620 is used for tanks like LNG tanks and Cryogenic tanks that require high internal pressure.

API 650 - Shop (Appendix J) or Field Erected

API 620 - Field Erected

API 650 - Compatible with any tank size

API 620 - Compatible only with tank sizes larger than 300 ft.

API 650 - -40 Deg. F to 500 Deg. F

API 620 - -325 Deg. F to 250 Deg. F

API 650 - 2.5 PSIG (pounds per square inch gauge) or 17.2 Kpa

API 620 - 15 PSIG

With this information in mind, we hope this article clarifies some of the critical differences between API Standards 650 and 620 regarding storage tanks. The parameters mentioned above of similarities and differences between the two API models can give a detailed observation of which model suits your business needs the best. Do you need a custom quote for the design, fabrication, and welding of the storage tanks? Get in touch with Mechartes right away!