Academic literature on the topic 'API 650 Tanks'

This paper presents the results of an investigation into the frangible joint behavior of tanks designed to API 650 rules. In such tanks, the roof-to-shell joint is intended to fail in the event of overpressurization, venting the tank and containing any remaining fluid. The reasoning behind present API design formulas is reviewed. Combustion analyses, structural analyses, and the results of testing are presented. Results show that higher pressures are reached before frangible joint failure than predicted by the present API 650 calculation. One consequence is that (for empty tanks) uplift of the bottom can be expected to occur more frequently than predicted using API 650. However, uplift does not necessarily mean bottom failure. Instead, the relative strength of the shell-to-bottom and roof-to-shell joints will determine failure. This ratio is larger for larger tanks. Recommendations are made as to possible changes in the design approach of API 650.

The analysis of tank nozzles for API 650, (American Petroleum Institute, 1998, API Standard 650, 10th ed.) tanks is a complex problem. Appendix P of API 650 provides a method for determining the allowable external loads on tank shell openings. The method in Appendix P is based on two papers, one by Billimoria and Hagstrom, 1997, ASME Paper No. 77-PVP-19 and the other by Billimoria and Tam 1980, ASME Paper No. 80-C2/PVP-5. Although Appendix P is optional, the industry has used it for a number of years for large diameter tanks. For tanks less than 120feet(33.6m) in diameter this Appendix is not applicable. In previously published papers, the authors used finite element analysis (FEA) to verify the experimental results reported by Billimoria and Tam for low-type nozzles. The analysis showed the variance between stiffness coefficients and stresses obtained by FEA and API 650 methods for tanks. In this paper, the authors have expanded the scope to include almost any size of nozzle as well as tank size. Stress factors for nozzles at different elevations on the shell are provided. Nozzles located away from a discontinuity are analyzed based on the method provided by the Welding Research Council (WRC), New York, Bulletin No. 297, 1987. Stress reduction factors have been developed using FEA for nozzles located closer to a discontinuity. Mathematical equations are provided together with the curves for the stress factors. The results of this paper have been incorporated into Appendix P of API 650 with the Addendum 3 of the 10th edition which was issued in 2003.

Liquid-storage tanks, designed as per the minimum requirements of API Standard 650 (1996), AWWA Standard D100 (1996), or any other design standard, should not be expected to remain fully elastic, or undamaged, when subjected to design ground shaking. Forces prescribed in design standards are only a fraction of those obtained from a linear elastic (no damage) response analysis. Force reductions are based on the expected overstrength and ductility of the system. However, there are no practical methods to quantify the effects of these reductions on potential damage to tanks. Some type of nonlinear analysis is needed to assess the tank's desired performance objectives. This paper presents a simplified nonlinear analysis for performance-based seismic design of tanks. It also presents a method of strengthening tanks by energy-dissipating base anchors. The simplified nonlinear analysis is illustrated for an unanchored tank, a tank anchored with traditional anchors, and a tank anchored with energy-dissipating anchors.

The paper deals with the analysis of reliability and safety of a welded tank for the storage of oil, which is located in the Czech Republic. The oil tank has a capacity of 125 thousand cubic meters. It is one of the largest tanks of its kind in the world. Safety is ensured by a steel outer intercepting shell and a double bottom. The tank was modelled in the programme ANSYS. The computational model was developed using the finite element method – elements SHELL181. A nonlinear contact problem was analysed for the simulation of the interaction between the bottom plate and foundation. The normative approach in design and check of tanks according to standards API 650, ČSN EN 14015, EEMUA 159 and API 653 is mentioned. The dominant loading of the filled tank is from oil. The normative solution is based on the shell theory, which considers constant wall thickness. For real tanks sheet thicknesses of individual courses increase with increasing depth. Stochastic sensitivity analysis was used to study the effect of the variability of the thickness of the ith course on the stress of adjacent courses. The Latin Hypercube Sampling method was implemented during analysis.

POME merupakan produk samping dari produksi minyak kelapa sawit dengan rasio terkandung dalam kelapa sawit 58.3%. POME dapat dimanfaatkan untuk dijadikan biogas dengan teknologi pengolahan proses anaerobic menggunakan tanki berpengaduk/Continuous Stirred Tank Reactor (CSTR). Tujuan dari penelitian ini adalah melakukan review dan analisis digester tank dengan fluida POME berdasarkan standard American Petroleum Institute yaitu API 650: Welded Steel Tanks for Oil Storage menggunakan variable design point method untuk menentukan ketebalan minimum pada setiap shell tergantung pada kedalamannya, sehingga setiap shell dapat memiliki ketebalan yang berbeda sehingga dapat memperkecil volume material dan biaya.Kemudian dilakukan simulasi dengan metode elemen hingga dengan beban dari tekanan hidrostatik yang menghasilkan tegangan maksimum 154.88 MPa, serta deformasi maksimum 5 mm dan beban dari gaya angin yang menghasilkan tegangan maksimum 1.31 MPa, serta deformasi maksimum 0.5 mm, lalu dibandingkan dengan sifat mekanik material bahwa yield strength terjadi pada tegangan 250-395 MPa sehingga tebal shell hasil perhitungan adalah aman. Kemudian dibandingkan ketebalan minimum hasil perhitungan dengan desain konstruksi yang hasilnya adalah desain konstruksi memiliki tebal yang lebih besar dari perhitungan tebal minimum sehingga desain konstruksi yang akan dipakai adalah aman.

Tangki merupakan wadah penyimpanan yang sering dipakai di berbagai industriseperti petrokimia, pengilangan, dan perminyakan. Tangki penyimpanan tidak hanya menjadi tempat penyimpanan untuk produk dan bahan baku tetapi juga menjaga kelancaran ketersediaan produk dan bahan baku. Selain itu, tangki juga dapat menjaga produk atau bahan baku dari kontaminan. Minyak kelapa murni adalah minyak yang dibuat dari bahan baku kelapa segar. Minyak kelapa murni memiliki daya simpan lebih dari 12 bulan sehingga diperlukan tangki penyimpanan yang memadai demi menjaga produk dari kontaminasi. ASTM 304, ASTM 316L, dan S32304 merupakan stainless steel yang digunakan untuk material plat tangki penyimpanan minyak kelapa murni. Stainless steel merupakan baja tahan korosi sehingga diharapkan dapat menjaga kualitas produk minyak kelapa murni. Penelitian ini bertujuan untuk merancang tangki penyimpanan minyak kelapa murni menggunakan stainless steel. Tangki penyimpanan dirancang memiliki kapasitas 75 m3. Tangki dirancang dengan membandingkan antara API 650 dengan BS 2654. Hasil perhitungan didapatkan ketebalan plat shell aktual 6 mm, ketebalan plat dasar aktual 6 mm, ketebalan plat dasar annular aktual 8 mm, dan ketebalan atap aktual 6 mm. Berdasarkan hasil perhitungan, tegangan pada tangki masih memenuhi syarat karena tegangan ijin tangki lebih besar dari tegangan akibat beban statis, tegangan circumferensial, dan tegangan longitudinal. Dengan demikian, desain tangki penyimpanan dapat dikatakan aman.Kata kunci: API 650, BS 2654, minyak kelapa murni, stainless steel, tangki penyimpananTank is a storage container that is often used by various industries such as petrochemical, refining, and petroleum. Storage tanks isnot only a storage for products and raw materials but also maintain the fluency availability of products and raw materials. Furthermore, the tank can also keep products or raw materials from contaminants. Virgin coconut oil is oil made from fresh coconut. Virgin coconut oil has storability of more than 12 months, so that adequate storage tanks are required to keep the product from contamination. ASTM 304, ASTM 316L, and S32304 are stainless steels used for the material of the virgin coconut oil storage tank. Stainless steel is corrosion resistant steel so it is expected to maintain the quality of virgin coconut oil product. This research aims to design storage tank of virgin coconut oil using stainless steel material. The storage tank is designed to have a capacity of 75 m3. The tank is designed by comparing between API 650 and BS 2654. The calculation results obtained the actual thickness of the shell plate is 6 mm, the actual bottom plate thickness is 6 mm, the actual annular bottom plate thickness is 8 mm, and the actual roof thickness is 6 mm. Based on the calculation, tank stress is still accepted because the allowable stress of tank is larger than the stress due static load, circumferential stress, and longitudinal stress. Thus, the design of storage tank is safe.Keywords: API 650, BS 2654, stainless steel, storage tank, virgin coconut oil

Field evidence has established that strong earthquakes can cause severe damage or even collapse of liquid storage tanks. Many tanks worldwide are built near the coast on soft soils of marginal quality. Because of the difference in stiffness between the tank (rigid), foundation (rigid) and the soil (flexible), soil-foundation-structure interaction (SFSI) has an important effect on the seismic response, often causing an elongation of the period of the impulsive mode. This elongation is likely to produce a significant change in the seismic response of the tank and will affect the loading on the structure. An issue not well understood, in the case of unanchored tanks, is uplift of the tank base that usually occurs under anything more than moderate dynamic loading. This paper presents a comparison of the loads obtained using “Appendix E of API STANDARD 650” of the American Petroleum Institute and the “Seismic Design of Storage Tanks” produced by the New Zealand Society for Earthquake Engineering. The seismic response assessed using both codes is presented for a range of tanks incorporating a range of the most relevant parameters in design. The results obtained from the analyses showed that both standards provide similar base shear and overturning moment; however, the results given for the anchorage requirement and uplift are different.

The present paper investigates sloshing effects on the earthquake design of horizontal-cylindrical and spherical industrial vessels. Assuming small-amplitude free-surface elevation, a linearized sloshing problem is obtained, and its solution provides sloshing frequencies, modes, and masses. Based on an “impulsive-convective” decomposition of the container-fluid motion, an efficient methodology is proposed for the calculation of seismic force. The methodology gives rise to appropriate spring-mass mechanical models, which represent sloshing effects on the container-fluid system in an elegant and simple manner. Special issues, such as the deformability of horizontal-cylindrical containers or the flexibility of spherical vessel supports, are also taken into account. The proposed methodology can be used to calculate the seismic force, in the framework of liquid container earthquake design, and extends the current design practice for vertical cylindrical tanks stated in existing seismic design specifications (e.g., API Standard 650 and Eurocode 8). The methodology is illustrated in three design examples.