scholarly journals Sealing Performances Research on PTFE Rotating Seal under Deep-Sea Environment

2015 ◽  
Vol 9 (1) ◽  
pp. 475-482 ◽  
Author(s):  
Xuepeng Cao ◽  
Cuihong Zhang ◽  
Bo Zou ◽  
Lei Li

In order to improve the environmental adaptability and sealing performance of the rotating seal, the principles and failure mechanisms of the rotating seal in ambient pressure in deep-sea is researched. It is proposed that the excessive friction caused by the ambient pressure and the magnitude of interference is the main reason for rotating seal failure. To reduce friction effect, a combined lip seal is designed, whose structure consists of a rotating seal made of polytetrafluoroethylene (PTFE) and an O-shaped fastening ring. The finite element analysis results indicate that the contact pressure in sealing surface increases with the growing magnitude of interference, but decreases when it exceeds the value 0.65mm. A suitable range (0.5×10 m ~0.6×10m) for the magnitude of interference is concluded for this combined seal. Finally, the designed PTFE rotating seal is tested in a deep-sea imitating hull, and the experimental results show that the seal is able to work reliably without leaking for more than 10 hours in the ambient pressure less than 30MPa, and verifies the design of the rotating seal is rational, which displays that the seal is available for the special requirement of deep-sea environment in short periods.

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Shi-Jun Wu ◽  
Can-Jun Yang ◽  
Ying Chen ◽  
Yan-Qing Xie

The cone valve plays an important role in high-pressure sealing applications. In this paper, a new high-pressure cone valve, based on the titanium alloy poppet-to-polyetheretherketone seat sealing structure, is proposed for deep-sea gas-tight water samplers. In order to study the sealing performance of the new valve, both the conforming poppet-seat contact model and the nonconforming poppet-seat contact model were evaluated. Finite element analysis based on the two models was performed and validated by experiments. The results indicate that the nonconforming poppet-seat contact model has a better sealing performance than the conforming poppet-seat contact model. The new cone valve also was applied in a gas-tight hydrothermal fluid sampler and successfully tested in a sea trial during the KNOX18RR cruise from 9 July to 12 August 2008.


Author(s):  
Quan Han ◽  
Yan Zhang ◽  
Haiyang Chen ◽  
Juekuan Yang ◽  
Yunfei Chen

In order to complete the mating and demating operations of the electrical connectors for underwater applications in the deep water environment, the pressure-balanced oil-filled (PBOF) structures are designed to compensate the huge water pressure. This paper focuses on the sealing performance of three sealing systems used in connectors, including the O-ring seals, rectangular seals, and U-cup seals. A method coupled the finite element analysis and elastohy-drodynamic lubrication (EHL) numerical model is presented to describe the issue. Results show that the rectangular seals perform best in fluid leakage, and O-ring seals are better in reducing the friction force. The oil leakages of the seals increase with the speed while the seawater leakages remain roughly constant. And the oil leakages of all the seals are larger than the seawater leakage. Types of seal rings, fluid viscosity and operation speed of connector can all influence the sealing performance of wet-mate connectors.


2014 ◽  
Vol 45 ◽  
pp. 292-299 ◽  
Author(s):  
Yi Zhou ◽  
Zhiqiang Huang ◽  
Li Tan ◽  
Yachao Ma ◽  
Chengsong Qiu ◽  
...  

2015 ◽  
Vol 817 ◽  
pp. 685-689
Author(s):  
Bin Zhou ◽  
Fu Shun Liu

According to the behavior of shape memory alloys, a structure of removable shape memory alloy pipe joint was designed. The contact manner of two parts of this structure is cone-globe. Cone-globe sealing is the key point of this structure’s sealing. Therefore the finite element analysis software ANSYS was used to simulate and calculate the sealing. The result shows that the width of the sealing surface and the contact stress altered with the change of structural parameters, which affected the sealing most. According to the value of the sealing surface’s width and the contact stress, the structural parameters including cone angle can be definitely settled.


2013 ◽  
Vol 397-400 ◽  
pp. 1045-1049
Author(s):  
Sheng Guan Qu ◽  
Wen Long Li ◽  
Bin Li

Two factors must be given considered in low friction cylinder , which are sealing and wear. A lower contact pressure can lead to seal failure. However, a heavier contact press can increase friction force and wear. In the present paper a method have been proposed to obtain the optimal contact pressure between PTFE wear-resistant ring and the steel bushing at first, with analysis of the relationship among the surface roughness, the sealing contact pressure and the leakage. Secondly,the piston groove Diameter has been designed by using the finite element analysis software of ABAQUS to simulate the Mooney-Rivlin model, which is corresponding to this optimal contact pressure. On the premise of meeting the requirement of the specific leakage standard between the cylinder and the wear-resistant ring, the optimal contact pressure and the corresponding piston groove size have been obtained, with different surface roughnesses of the friction pairs.


Author(s):  
Md Ebrahim Khalil Bhuiyan ◽  
Mohammad Shavezipur

Abstract A new design concept for MEMS capacitive pressure sensors is presented that can be used to improve the linearity of the capacitance-pressure (C-T) response of the sensor. The sensor uses an extra dimple mask and etching step in the fabrication process of the device to create small bumps under the pressure sensitive and flexible membrane. Different designs, including a conventional sensor, are modeled and simulated using FEM coupled-field multiphysics solver in ANSYS®. Polycrystalline silicon is used as the structural material in the simulations. Coefficient of linear correlation between device capacitance and ambient pressure is used as the linearity factor to quantitatively compare the performance of different sensors. The finite element analysis show that the linearity factor improves from 0.938 for a conventional design to 0.973 for a design with a central bump. For a design with five bumps (one at the center of membrane and four off-center) the linearity factor increases to 0.997 for bumps of 1.5 μm thickness for wide pressure range of 0.0–4.0 MPa. The proposed design can be tailored for different applications that require certain sensor materials or different pressure ranges by using optimized sensor dimensions.


2013 ◽  
Vol 444-445 ◽  
pp. 1379-1383 ◽  
Author(s):  
Kai Bo Cui ◽  
Jun Qi Qin ◽  
Chang Chun Di ◽  
Yan Feng Yang

Application of super elasticity theory and nonlinear theory, based on finite element method and the Abaqus software, the performance of Y ring rubber seal, such as the Von Mises stress, the sealing ring deformation and the contact pressure were simulated and analyzed under the influence of changeable hydraulic pressure. According to seal failure criterion, the effect of hydraulic pressure changes on the sealing performance were studied. Results show that, the maximum stress appears in the intersection of lips, the largest deformation area near the inner lip. The root has greater contact pressure, which would result in bitten phenomenon or aggravate wear.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yang Liu ◽  
Zhanghua Lian ◽  
Junwen Chen ◽  
Shengping Kuang ◽  
Yisheng Mou ◽  
...  

In order to reduce the failure accidents of conventional packers, a kind of sealing structure of retrievable packers is designed, which can provide reference for optimizing the sealing performance and pressure capacity of packers. And theoretical calculation and experimental research on their sealing performance and pressure capacity are carried out through the finite element analysis on the contact with large deformation based on Abaqus and experimental study. The results show that the upper packer is subjected to greater stress and mainly plays a sealing role in the sealing process. In order to improve the sealing performance of the packer, the height of the upper and lower packer should be preferentially selected about 60 mm, the height of the middle rubber cylinders should be about 50 mm, and the thickness of the packer should be about 21 mm. The newly designed rubber cylinders can meet 150°C. The newly designed rubber cylinders can meet the sealing function and pressure bearing function under the condition of 10,000 Psi and 150°C. The newly designed rubber cylinder can satisfy the function of sealing and pressure-bearing under 140°C and 10,000 Psi. The whole experiment shows that the capacity of bearing pressure and sealing is stable, which can better meet the requirements of field use.


2019 ◽  
Vol 13 (3) ◽  
pp. 5334-5346
Author(s):  
M. N. Nguyen ◽  
L. Q. Nguyen ◽  
H. M. Chu ◽  
H. N. Vu

In this paper, we report on a SOI-based comb capacitive-type accelerometer that senses acceleration in two lateral directions. The structure of the accelerometer was designed using a proof mass connected by four folded-beam springs, which are compliant to inertial displacement causing by attached acceleration in the two lateral directions. At the same time, the folded-beam springs enabled to suppress cross-talk causing by mechanical coupling from parasitic vibration modes. The differential capacitor sense structure was employed to eliminate common mode effects. The design of gap between comb fingers was also analyzed to find an optimally sensing comb electrode structure. The design of the accelerometer was carried out using the finite element analysis. The fabrication of the device was based on SOI-micromachining. The characteristics of the accelerometer have been investigated by a fully differential capacitive bridge interface using a sub-fF switched-capacitor integrator circuit. The sensitivities of the accelerometer in the two lateral directions were determined to be 6 and 5.5 fF/g, respectively. The cross-axis sensitivities of the accelerometer were less than 5%, which shows that the accelerometer can be used for measuring precisely acceleration in the two lateral directions. The accelerometer operates linearly in the range of investigated acceleration from 0 to 4g. The proposed accelerometer is expected for low-g applications.


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