Reliability analysis of integral hot deep drawing and cold flow forming process for large-diameter seamless steel gas cylinders
Refillable seamless steel gas cylinders are widely used to store and transport clean energy, such as compressed natural gas (CNG) and hydrogen. Conventional manufacturing processes have some disadvantages which bring potential hazard for the safety and reliability of cylinders. After reviewing the conventional manufacturing processes, a hot deep drawing process is recommended with solid steel billet stock. Based on this, an integral manufacturing process with cold flow forming process is proposed for large-diameter seamless steel gas cylinders to improve the performance of gas cylinders. Several cylinder properties including size error and fatigue lives are compared. The uniformity of wall thickness is further improved for gas cylinders by the integral process. The gas cylinders obtain fine surface finish, high tolerance of size, and commensurately enhanced fatigue lives. Meanwhile, the failure mode and effect analysis (FMEA) method is adopted to study the reliability of steel gas cylinders. The reliability of steel gas cylinder with cold flow forming process is compared with the conventional processes. The probabilities of most causes are ameliorated, except for the lamination that is usually resulted from wrong flow forming process parameters, e.g., high reduction rate and feed rate. As a whole, there is a marked drop in the risk priority number of the integral process. It is worth to further spread this in gas cylinder industry.
KeywordsCold flow forming Hot deep drawing Steel gas cylinders Fatigue life Reliability
Unable to display preview. Download preview PDF.
The authors are grateful to all related engineers from Zhejiang Jindun Pressure Vessel Co. Ltd. for full cooperation to proceed FMEA method for common failure modes in the manufacturing process.
This study received financial support from the National Natural Science Foundation of China (Grant No. 51605435).
- 4.Zalosh R (2008) CNG and hydrogen vehicle fuel tank failure incidents testing, and preventive measures. In Proceedings of 2008 AIChE Spring Meeting and Global Congress on Process Safety.Google Scholar
- 5.Chamberlain S (2004) Development of a physics of failure model and quantitative assessment of the fire fatality risks of compressed natural gas bus cylinders. Dissertation, University of MarylandGoogle Scholar
- 18.Marini D, Cunningham D, Xirouchakis P, Corney JR (2016) Flow forming: a review of research methodologies, prediction models and their applications. Int J Mech Eng Technol 7:285–315Google Scholar
- 23.Yin X, Chen Z, Zhang W (2014) Effect of cold rolling processing on properties of high pressure cylinders. Press Vessel Technol 31(2):13–18 (In Chinese)Google Scholar
- 25.Stamatis DH (2003) Failure mode and effect analysis: FMEA from theory to execution, 2nd edn. ASQ Quality Press, MilwaukeeGoogle Scholar