For the sealing structure of subsea pipeline connectors, it is crucial to understand the maximum equivalent stress of the sealing ring, the normal force generated by the pressure effect of the internal fluid acting on the contact area of the flanges and the sealing ring, and the displacement of the flange in the pre-tightening state and the working state. This paper proposes an equivalent calculation method (ECM) to quickly compute the values of these three variables. A theoretical model for the parallel contact of the axially symmetric object and an elastic foundation is proposed based on the dimensionality reduction method and Hertzian theory. Considering the contact and structural characteristics of the flanges and the sealing ring of the sealing structure, an equivalent hollow cylinder model is introduced. By combining these two models, along with the long hollow cylinder theory, theoretical formulas for the maximum equivalent stress, the normal force, and the flange displacement in the pre-tightening state and the working state of the sealing structure are derived. In addition, finite element simulations were conducted on the sealing structure of different sizes and working states. A comparative analysis was performed between the simulation results and the theoretical formulas results. The results show that, within the yield strength of the sealing ring, the maximum relative deviation of the three theoretical formulas is less than 10%. The theoretical formulas can be used for the design and engineering application of the sealing structure of subsea pipeline connectors.
JiangDMengWHuangY, et al. Characterization of physical field and flow assurance risk analysis of subsea cage-sleeve throttling valve. Earth Sci Front2021; 9: Article 786996.
2.
YueYLiuZZuoX. Integral layout optimization of subsea production control system considering three-dimensional space constraint. Processes2021; 9(11): 1947.
3.
WangYLuoWLiuS, et al. A model for reliability assessment of sealing performance of the c-shaped metal sealing ring at the outlet of the subsea tubing hanger. Ocean Eng2022; 243: 110311.
4.
ZhangKLiuJDuanM.Analytical calculation method for predicting compression deformations and sealing performance of subsea connector under operating condition. Int J Press Vessel Piping2023; 202: 104902.
5.
ZhangKChengHLiuJ, et al. Analytical calculation method for predicting contact loads and structural strength of metallic gasket of subsea connectors under thermal loads. Proc IMechE, Part M: J Engineering for the Maritime Environment2024; 238(1): 57–67.
6.
KeYCYaoXFYangH, et al. Gas leakage prediction of contact interface in fabric rubber seal based on a rectangle channel model. Tribol Trans2017; 60(1): 146–153.
7.
YangCGuoLLiuJ, et al. The effects of the initial geometrical errors on the piston friction and sealing performance in a buoyancy regulator of an underwater glider. J Test Eval2024; 52(4): 2435–2450.
8.
LiuXHeSZhengJ.Analysis of sealing characteristics of lip seal rings for deep-sea separable pressure vessels. Appl Sci2023; 13(11): 6843.
9.
WuDMaYWangZ, et al. Numerical and experimental study of reciprocating seals in seawater hydraulic variable ballast components for 11,000-m Operation. Tribol Trans2023; 66(1): 92–103.
KorobchukMV.Elastomer materials for application in equipment of subsea production systems. Inorg Mater Appl Res2022; 13(5): 1161–1172.
12.
LanWJWangHXZhangX, et al. Sealing properties and structure optimization of packer rubber under high pressure and high temperature. Pet Sci2019; 16(3): 632–644.
13.
ZhengCZhengXQinJ, et al. Nonlinear finite element analysis on the sealing performance of rubber packer for hydraulic fracturing. J Nat Gas Sci Eng2021; 85: 85.
14.
LiuJDengKLiuS, et al. Mechanical behavior and structure optimization of compressed PHP packer rubber. J Mater Eng Perform2021; 30(5): 3691–3704.
15.
HuGWangGLiM, et al. Study on sealing capacity of packing element in compression packer. J Braz Soc Mech Sci Eng2018; 40(9): Article no. 438.
16.
LiuDYunFJiaoK, et al. Structural analysis and experimental study on the spherical seal of a subsea connector based on a Non-standard O-ring seal. J Mar Sci Eng2022; 10(3): 404.
17.
LiYJiangWZengL, et al. Design and characterization of subsea pipeline rehabilitation connectors. Ocean Eng2023; 288: 115967.
18.
HuangXXuTLiuY.Experimental and thermal-structure coupling analysis for oil and water-swellable packer. Energy Sci Eng2023; 11(9): 3055–3069.
19.
JinLZhaoDLiuJ.A visco-hyperelastic constitutive model for rubber considering the strain level and one case study in the sealing packer. Acta Mech Solida Sin2023; 36(5): 710–723.
20.
LiJChangYXiuZ, et al. A local stress-strain approach for fatigue damage prediction of subsea wellhead system based on semi-decoupled model. Appl Ocean Res2020; 102: 102306.
21.
ProdanVD.Calculation of the tightening stress of the fastening parts of flange joints with a lenticular gasket. Chem Pet Eng1983; 18(5): 191–193.
22.
MurtagianGRFanelliVVillasanteJA, et al. Sealability of stationary metal-to-metal seals. J Tribol-Trans ASME2004; 126(3): 591–596.
23.
HendrieCFda MotaACHeijnenWH. Wellheads for an HP/HT future. In: Abu Dhabi international petroleum exhibition and conference, Abu Dhabi, 2006. SPE.
24.
Murali KrishnaMShunmugamMSSiva PrasadN. A study on the sealing performance of bolted flange joints with gaskets using finite element analysis. Int J Press Vessel Piping2007; 84(6): 349–357.
25.
KaculiJ.Next generation HPHT subsea wellhead systems design challenges and opportunities. In: Offshore technology conference, Houston, 2015. OTC.
26.
Van ZylG. Determination of target bolt tension for flanges with lens gaskets. In: ASME pressure vessels and piping conference, Waikoloa, HI, 2017.
27.
LiYZhaoHWangD, et al. Metal sealing mechanism and experimental study of the subsea wellhead connector. J Braz Soc Mech Sci Eng2020; 42(1): Article no. 26.
28.
YunFWangGYanZ, et al. Analysis of sealing and leakage performance of the subsea collet connector with lens-type sealing structure. J Mar Sci Eng2020; 8(6): 444.
29.
ZhangKYiQLiuJ, et al. A new analytical model for compressive amounts of metallic sealing gasket of subsea connectors. Ships Offshore Struct2024; 19(8): 1210–1217.
30.
LiYSuHWangY, et al. Research on bearing capacity and sealing contact characteristics of the subsea wellhead connector. Proc IMechE, Part M: J Engineering for the Maritime Environment2023; 237(1): 153–165.
31.
WangWYunFSunH, et al. The research and experiments on contact sealing theory of the underwater clamp connector. Machines2021; 9(11): 262.
32.
ZhangKHuangHDuanM, et al. Theoretical investigation of the compression limits of sealing structures in complex load transferring between subsea connector components. J Nat Gas Sci Eng2017; 44: 202–213.
33.
SaathoffMRosemeierM.Stress-based assessment of the lifetime extension for wind turbines. J Phys Conf Ser2020; 1618: 052–057.
34.
ZengWXueYSunY, et al. Sealing reliability assessment of deep-water oil and nature gas pipeline connector considering thermo-mechanical coupling. Proc IMechE, Part M: J Engineering for the Maritime Environment2022; 236(1): 196–208.
35.
WangYLiuSChenZ, et al. Dynamic Bayesian networks for reliability evaluation of subsea wellhead connector during service life based on Monte Carlo method. J Loss Prev Process Ind2021; 71: 104487.
36.
WangYWangCLiuG, et al. An assessment method of sealing performance and stress intensity factors at crack tip of subsea connector metal sealing rings. Energies2022; 15(13): 4680.
37.
PopovV.Contact mechanics and friction: physical principles and applications. Springer, Berlin, 2010.
38.
TimoshenkoSGoodierJN. Theory of elasticity. McGraw-Hill, New York, 1951.
39.
JohnsonKLJohnsonKL.Contact mechanics. Cambridge University Press, Cambridge, 1987.
40.
TranterCJCraggsJW.XXXIII. The stress distribution in a long circular cylinder when discontinuous pressure is applied to the curved surface. Lond Edinb Dubl Philos Mag J Sci1945; 36(255): 241–250.
41.
PanHH.Stresses in a long hollow cylinder subjected to a band of uniform pressure on the outer surface. Zeitschrift für angewandte Mathematik und Physik ZAMP1963; 14(1): 23–37.
42.
LiuJNiHZhouR, et al. A simulation analysis of ball bearing lubrication characteristics considering the cage clearance. J Trib-Trans ASME2023; 145(4): Article no. 044301.
