Creep-ratcheting behavior of PTFE gaskets under various temperatures

Zheng, Xiaotao; Xiang, Wen; Wang, Wei; Gao, Jiuyang; Wang, Lin; Ma, Linwei; Yu, Jiuyang

doi:10.1016/j.polymertesting.2017.04.005

Cited by 33 publications

(14 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…19(a). It is worth noting that the PTFE gasket is used in order to measure the rotation angle of flange at room temperature conveniently, and the mechanical properties of PTFE gasket are tested in detail under compression condition [30,31,32,33] . Moreover, the bolts are made by 35CrMo steel because it is one of the most widely used bolt materials in process industries [34,35] .…”

Section: Measurement Of Rotation Angles For Bolted Flange Jointsmentioning

confidence: 99%

Measurement of small rotation angle of flange joints by a novel flexure magnifying mechanism

et al. 2019

Self Cite

View full text Add to dashboard Cite

Bolted flange joints are indispensable components in process industries due to the good sealing, assemble and disassemble capacities. Generally, the flange rigidity characterized by the rotation angle is a key index to evaluate the sealing tightness of flange joints. However, the rotation angle of flange is usually too small (less than 1º) to monitor during the assemble and operation stages. Accordingly, a novel flexure magnifying mechanism is designed to measure the small rotation angle of flange joints under internal pressure and external bending moment. The magnification factor and calculation approach of the flexure amplification mechanism are deduced and verified by experimental data and finite element simulation. Results indicate that the proposed measuring apparatus has good performance to monitor the maximum rotation angle. It is of great interest that the measured location of the maximum rotation angle is in good agreement with that in the experiment, and the average error is 7.3%, which is acceptable for practical application. Additionally, the leakage rate at the top of flange joints slowly and almost linearly increases with the increment of external bending moment ascribing to the decrease the gasket stress near the top of flange joints.

show abstract

Section: Measurement Of Rotation Angles For Bolted Flange Jointsmentioning

confidence: 99%

Measurement of small rotation angle of flange joints by a novel flexure magnifying mechanism

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Constituting equation (7) and the material parameters into equations (1) and (4), then the relationships of compression and resilience curves are obtained and superposed in Figure 4. Results clearly show that the predicted results are in good agreement with those experimental data under various temperatures and stress rates.…”

Section: Cyclic Stress-strain Curves Of Nafcmentioning

confidence: 99%

“…However, the compressive modulus changes slightly when the stress rate is greater than 16 MPa/s or the temperature is greater than 150 C. This means that the effect of stress rate and temperature on the compressive modulus can be neglected under these conditions. It should be noted that the proposed theoretical model from equation (1) to equation (7) can also use to predict the compressive modulus under various loading conditions, as shown in Figure 5. Results show that the predicted results agree very well with the experimental data under different compressive conditions.…”

Section: Cyclic Stress-strain Curves Of Nafcmentioning

confidence: 99%

“…It is known that the NAFC sheet is usually subjected to compressive loads to meet its sealing function. Sometimes, cyclic compressive loads with small or great stress amplitudes owing to the randomness of fluid-induced vibration, seismic load, pressure or temperature fluctuations, repeated start-up or shut-down and so on 6–8 are inevitable for NAFC sheet in engineering application. Under repeated compressive conditions, the accumulated compression strain of NAFC will be produced which may decrease the sealing performance of NAFC significantly, especially at relatively high temperatures.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Compressive ratcheting and creep of non-asbestos fibre composite considering temperature effect

Zheng

Dai

et al. 2018

Journal of Composite Materials

Self Cite

View full text Add to dashboard Cite

Compressive ratcheting response and creep of non-asbestos fibre composite are tested based on a designed compression–compression clamp for plate-shape specimens. The influences of temperature, stress amplitude and stress rate are discussed in detail. A two-stage constitutive model is developed to describe the compression-resilience relationship of non-asbestos fibre composite. Results present that a crescent-shaped stress–strain relationship of non-asbestos fibre composite is observed under repeated compression, and the proposed two-stage constitutive model can predict the compression-resilience curve for the first cycle very well under various temperatures and stress rates. Additionally, the ratcheting strain of non-asbestos fibre composite obviously enhances with increasing the temperature. However, it has a little change when the stress rate and stress amplitude are varied based on the experimental data. The ratcheting strain rate per cycle reduces promptly during about the first 75 cycles, and it is always less than 1 × 10−4 per cycle during the subsequent cycles and tends to shakedown. Moreover, the ratcheting strain with small stress amplitude is very close to the creep deformation at the same testing time and peak stress under different temperatures. This indicates that the ratcheting strain of non-asbestos fibre composite under fatigue loads with small stress amplitude can be evaluated equivalently by the corresponding creep deformation with high precision.

show abstract

“…Under practical operating conditions, gaskets are usually subjected to repeated compressive loads with small or great stress amplitudes because of the randomness of vibrations, pressure or temperature fluctuations, start‐up or shut‐down processes, and so on . In these cases, the accumulated deformation of RGSWSSI usually occurs, which is essential to evaluate the sealing performance of joints, especially at elevated temperatures …”

Section: Introductionmentioning

confidence: 99%

Ratcheting effect of reinforced graphite sheet with stainless steel insert (RGSWSSI) under cyclic compression at elevated temperature

Zheng

Dai

Chen

et al. 2018

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

Ratcheting and creep of reinforced graphite sheet with stainless steel insert (RGSWSSI) are tested under cyclic stress‐controlled compression by a self‐designed clamp from 500°C to 600°C. The effects of insert type, temperature, stress amplitude, stress rate, creep, and loading sequence are considered. Results present that ratcheting deformations for RGSWSSI with 316‐L stainless steel tanged and bonded insert approach to each other and show little rate dependence, while they slightly increase with the increment of stress amplitude and temperature. Moreover, obvious ratcheting effect takes place under cyclic pulsating loads with the peak stress of 32 MPa at 500°C or higher. The accumulated deformations of RGSWSSI under small stress amplitude only increase during about the first 25 cycles and then always turn to shakedown. It can also be estimated by the corresponding static creep strain in practical engineering with good accuracy at high temperature. This work provides important data and understanding of RGSWSSI under harsh fluctuating loads.

show abstract

Creep-ratcheting behavior of PTFE gaskets under various temperatures

Cited by 33 publications

References 20 publications

Measurement of small rotation angle of flange joints by a novel flexure magnifying mechanism

Measurement of small rotation angle of flange joints by a novel flexure magnifying mechanism

Compressive ratcheting and creep of non-asbestos fibre composite considering temperature effect

Ratcheting effect of reinforced graphite sheet with stainless steel insert (RGSWSSI) under cyclic compression at elevated temperature

Contact Info

Product

Resources

About