Flange Tightening Evaluation Method for Flat Face Flange With Full Face Gasket

2013 ◽  
Author(s):  
Masako Mori ◽  
Akira Nebu ◽  
Takashi Kanno
Keyword(s):  
Evaluation Method ◽  
Large Diameter ◽  
Test Results ◽  
Axial Loads ◽  
Tightening Torque ◽  
Japanese Industrial Standard ◽  
Sealing Performance ◽  
Pressure Tests ◽  
Full Face ◽  
Bolted Flange

Appropriate flange tightening methods for flat face flanges with full face gaskets are discussed to improve the sealing performance of the bolted flange joints and the workability of flange tightening work. In general, relatively larger tightening torque is required for a flat face flange with a full face gasket compared to the flange with a ring gasket when we calculate the required tightening torque based on the latest Non-mandatory Japanese Industrial Standard (JIS) evaluation method, “JIS B 2205-1991, Basis for calculation of pipe flanges”[1]. Especially, for the flat face flanges with large diameter and with fewer tightening bolts, this tendency becomes stronger. This problem sometimes causes a conflict when the flange torque calculation of the minimum required torque value to resist hydrostatic end force at the maximum design pressure of the flange is larger than the maximum allowable torque derived from flange or bolt strength. So, in this paper, surface stress of several diameter flange faces were measured to clarify whether or not the required stress is applied on the surface of the flat face flanges with full face gaskets. In addition, pressure tests were carried out to clarify the sealing performance under the condition of circumferentially non-uniform tightening load in each diameter flat face flange with full face gasket. Based on these test results, minimum flange-tightening bolt axial loads have been summarized to ensure the sealing performance of the flat face bolted flanges with full face gaskets.

Application of Plastic Region Bolt Tightening to Flange Joint Assembly: Behavior of Large Diameter Flange

2009 ◽  
Author(s):  
Shinobu Kaneda ◽  
Hirokazu Tsuji
Keyword(s):  
Internal Pressure ◽  
Large Diameter ◽  
Plastic Region ◽  
Load Factor ◽  
Past Study ◽  
Flange Joint ◽  
The Past ◽  
Sealing Performance ◽  
Assembly Behavior ◽  
Bolted Flange

In the past study the plastic region tightening has been applied to the bolted flange joint with smaller nominal diameter and its advantages have been demonstrated, however, behavior of the bolted flange joint with larger diameter is not investigated. Flange rotation of the bolted flange joint with large diameter increases when the internal pressure is applied. Gasket stress is not uniform and it may cause leak accident. So, it is necessary to investigate the behavior of the larger diameter flange. The present paper describes the behavior of bolted flange joint with large diameter under plastic region tightening. Firstly, API 20-inch flange joint tightened to the plastic region by bolt with a smaller diameter and superiority in the uniformity of the axial bolt force is demonstrated. And then the internal pressure is applied to the bolted flange joint and the behavior of the additional axial bolt force is demonstrated. The axial bolt force decreases with increasing the internal pressure, and the load factor is negative due to increasing of the flange rotation. However, the load factor of the bolted flange joint tightened to the plastic region by using the bolt with the smaller diameter approached zero. Using the bolts with smaller diameter is advantageous to the flange joint with the larger diamter, whose load factor is negative, to prevent the leakage. Additionally, the leak rate from the bolted flange joint is measured and the sufficient sealing performance is obtained.

Characterization of Sealing Behavior of Gaskets for the Leak Rate Based Design of Gasketed Bolted Flanged Connections

2008 ◽  
Author(s):  
Takashi Kobayashi
Keyword(s):  
Internal Pressure ◽  
Testing Procedure ◽  
Test Method ◽  
Leak Rate ◽  
Test Results ◽  
Japanese Industrial Standard ◽  
Sealing Performance ◽  
Stress Levels ◽  
Spiral Wound

This paper discusses the sealing behavior of gaskets according to the gasket testing procedure HPIS Z104 established in Japan. The testing procedure consists of eleven gasket stress levels while the internal pressure is constant. It takes about 3 hours to complete one test, which is acceptable for gasket manufacturers. The test method is going to be effective as the Japanese Industrial Standard (JIS) soon. Several sheet gaskets and spiral wound gaskets were tested based on the test method HPIS Z104 and test results are compared and discussed in this paper. Based on the test results, experimental formulas are proposed to approximate the sealing behavior of gaskets. It is shown that the sealing behavior of gaskets can be well characterized using the proposed testing procedure and the experimental formulas. The formulas have the possibility of application to the design of gasketed bolted flanged connections. It is also shown that the sealing performance of spiral wound gaskets with graphite and PTFE fillers is as good as that of sheet gaskets under an equal gasket load.

Improvement of Flange Tightening Method for Small Bore Low Rating Bolted Flanges

2010 ◽  
Author(s):  
Masako Mori ◽  
Akira Nebu ◽  
Takashi Kanno
Keyword(s):  
Axial Force ◽  
The Other ◽  
Test Results ◽  
Other Hand ◽  
Sealing Performance ◽  
Bolted Flange ◽  
Seating Surface ◽  
Spiral Wound

An appropriate flange tightening methods for small bore and low rating piping flange joints are clarified to improve the sealing performance of the bolted flange joints and the workability of flange tightening work. It is said that lubricant on the screw of the bolts and the nut-seating surface can minimize the variability of axial force acting on flange bolts, while this process might make it harder to tight the bolts uniformly especially for small bore low rating flanges. So, in this paper the appropriate condition to apply lubricant is clarified by a series of bolt tightening tests and sealing tests results. On the other hand, for the bolted flanges applying spiral wound gaskets, measuring the gasket compress dimensions help us to prevent uneven tightening balance and to perform the appropriate tightening work. Appropriate gasket compress dimensions are also clarified to ensure the sealing performance for the flanges based on the sealing tests results. Based on these test results, recommended flange-tightening methods have been summarized as an instruction and tightening work procedure to improve the sealing performance of the bolted flanges and the workability of flange tightening work.

Practical Evaluation of PTFE Thermal Behavior Using the Hot Blowout Thermal Cycling Test

2012 ◽  
Author(s):  
Anita R. Bausman ◽  
A. Fitzgerald (Jerry) Waterland
Keyword(s):  
Thermal Cycling ◽  
Compressive Load ◽  
Temperature Limit ◽  
Cycling Performance ◽  
Current Status ◽  
Test Results ◽  
Sealing Performance ◽  
Practical Evaluation ◽  
Bolted Flange

Differential thermal expansion between polytetrafluoroethylene (PTFE) gasket materials and metallic flange/bolt systems, combined with thermally influenced creep relaxation characteristics of all PTFEs, creates limitations in the ability of some PTFE gasket materials to provide long term, reliable sealing performance in process or thermal cycling applications. ASTM F-36 gasket recovery data is sometimes used to assess a gasket’s thermal cycling capabilities; however, it is a poor means of establishing suitability for cycling performance as it is a short duration, ambient temperature test that measures recovery, or springback, of the gasket after the compressive load has been completely released. In order to provide a direct qualification of thermal cycling performance and capabilities, the Hot Blowout Thermal Cycling (HOBTC) test was developed under the guidance of the PVRC (Pressure Vessel Research Council)Bolted Flange Connection Committee as part of the 1995 PTFE Gasket Protocol. The HOBTC test results provide a practically applicable temperature limit under which the tested material, typically a PTFE, can operate safely. In addition, test data reported graphically provide additional insight about the long term behavior of the PTFE material. This paper reviews the current status of the HOBTC test, in the process of being made into an ASTM standard, and practical application of test results to achieve reliable gasket performance.

A Determination Method of Bolt Preload for Bolted Pipe Flange Connections With Metal Gaskets Under Internal Pressure

2015 ◽  
Author(s):  
Koji Kondo ◽  
Toshiyuki Sawa
Keyword(s):  
Internal Pressure ◽  
Room Temperature ◽  
Bolted Joints ◽  
Test Results ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Bolted Flange ◽  
The Given ◽  
Outside Diameter ◽  
Better Than

FEM calculations and leakage experiments are carried out for bolted flanged connections with metal flat gaskets. It is found that the sealing performance of bolted flanged connections with raised face metal gaskets under internal pressure is improved significantly when the contact gasket stress reaches the gasket yield stress. In our FEM calculations it is demonstrated that the contact gasket stress at the outside diameter is bigger than that at the inside diameter due to the flange rotation. It is also found from the leakage test results and the FEM calculations that the sealing performance of the bolted flange connections with metal flat gasket is better than that of the metal gasket in platen device tests,. In addition, the contact stress in the joints with RTJ (ring type joint) gasket is examined and 4 stress peaks on the oval type and 8 peaks on the octagonal type are found. From the obtained results, a method for determining the bolt preloads in the bolted joints using flat metal gaskets and RTJ gaskets under internal pressure is proposed taking account the given allowable leak rate. Finally, the leak rates for bolted flanged connections tightened under internal pressure are compared with the experimental results. The new method can be proposed for determining the bolt preload for bolted flange connections with metal gaskets under internal pressure at room temperature.

Optimization of Valves Packings Through Characterization and Calculation

2019 ◽  
Author(s):  
Hubert Lejeune ◽  
Frédéric Joulain
Keyword(s):  
Emissions Reduction ◽  
Test Results ◽  
Fugitive Emissions ◽  
Low Friction ◽  
Friction Forces ◽  
Full Characterization ◽  
Energy Efficiency Improvement ◽  
Sealing Performance ◽  
Low Load ◽  
Bolted Flange

Abstract In the valve industry, there is combined demand from the end-users for fugitive emissions reduction and energy efficiency improvement through the reduction of stem/packing friction forces. These two different goals will involve opposite trends on the load to be applied on the packing i.e. high load for good tightness and low load for low friction. Thus, the ability to define optimal ranges of packing tightening is important. Nevertheless, no standardized method for packing calculation nor packing full characterization (mechanical, friction, sealing performance vs. packing load,..) exists in Europe, as for bolted flange joints and associated gasket with EN1591-1 [1] and EN13555 [2]. In collaboration with ESA (European Sealing Association, www.europeansealing.com) and FSA (Fluid Sealing Association, www.fluidsealing.com), the Fluid Equipment Committee of CETIM has developed a tool for the optimization of packing. A set of tests enables to get the packing characteristics needed for the calculation. These tests can also be used for the comparison of packing materials and/or installation procedures performances in defined test conditions. This paper details the proposed calculation method and describes the associated test rigs and procedures. First test results and a calculation example are also given to show how the method works.

Improvement of Flange Tightening Method for Small Bore Low Rating Bolted Flanges

2010 ◽  
Author(s):  
Masako Mori ◽  
Akira Nebu ◽  
Takashi Kanno
Keyword(s):  
Axial Force ◽  
The Other ◽  
Test Results ◽  
Other Hand ◽  
Sealing Performance ◽  
Bolted Flange ◽  
Seating Surface ◽  
Spiral Wound

An appropriate flange tightening methods for small bore and low rating piping flange joints are discussed to improve the sealing performance of the bolted flange joints and the workability of flange tightening work. The lubricant on the thread of the bolts and the nut-seating surface can minimize the variability of axial force acting on flange bolts, however this process might make it harder to tight the bolts uniformly especially for small bore low rating flanges. In this paper the appropriate condition to apply lubricant is clarified by a series of bolt tightening tests and sealing tests results. On the other hand, for the bolted flanges using spiral wound gaskets, measuring the gasket compressed dimensions help us to prevent uneven tightening balance and to perform the appropriate tightening work. Appropriate gasket compressed dimensions are also clarified to ensure the sealing performance for the flanges based on the sealing tests results. Based on these test results, recommended flange-tightening methods have been summarized as an instruction in tightening work procedure to improve the sealing performance of the bolted flanges and the workability of flange tightening work.

The Sealing Performance of a Large Diameter Bolted Joint Under Elevated Temperature

2007 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Naoki Kawasaki ◽  
Yoshio Takagi ◽  
Hiroyasu Torii
Keyword(s):  
Elevated Temperature ◽  
Internal Pressure ◽  
Large Diameter ◽  
Stress Distributions ◽  
Test Results ◽  
Flange Connection ◽  
Gas Leakage ◽  
Nominal Diameter ◽  
Sealing Performance ◽  
Diameter Pipe

Flange rotation with internal pressure affects the sealing performance of pipe flange connections more with increasing the pipe nominal diameter. Therefore, it is hard to estimate the sealing performance of pipe flange connections with larger nominal diameter by using the test results of the sealing performance for pipe flange connections with small nominal diameter. In this study, the 20" diameter pipe flange connection was experimentally used as a large nominal diameter pipe flange connection and analyzed the stress in the connection. In the experiments, the sealing performance of the pipe flange connection was evaluated by measuring the amount of gas leakage at 50 °C and 100 °C under internal pressure. Non-asbestos graphite gaskets were used in the experiments. The bolts and nuts were tightened according to the Japanese method (HPIS Z103 TR). The gasket contact stress distributions of larger nominal diameter pipe flange connection were calculated by FEM under elevated temperature conditions as well as internal pressure application. The estimated results were compared with the experimental results. The results were also compared with the small nominal diameter test result and discussed.

The Sealing Behavior of Large Diameter Flanged Connections and a Method to Determine Bolt Loads to Satisfy Tightness Criteria

2011 ◽  
Author(s):  
Takashi Kobayashi ◽  
Masahiro Kogasaka ◽  
Kengou Nishiura ◽  
Kazuaki Uchiyama
Keyword(s):  
Internal Pressure ◽  
Thrust Force ◽  
Environmental Concern ◽  
Large Diameter ◽  
Small Diameter ◽  
Test Results ◽  
Recent Increase ◽  
Sealing Performance ◽  
The Difference

With the recent increase of a safety and environmental concern, the tightness of gasketed flanged connections becomes an important issue. However, the estimation of bolt loads to satisfy the tightness of gasketed flanged connections has not yet been fully established, especially in the case of large diameter flanges. In this paper, the sealing behavior of a large diameter gasketed flanged connection, in which 16 inch blind flanges were used, was examined experimentally. The variations of bolt loads were also measured when the flanged connection was subjected to an internal pressure. In the experiments, two kinds of sheet gaskets were used. It was shown that the bolt loads of large diameter flanges were reduced significantly and a gross leak occurred due to a large thrust force caused by an internal pressure and that the gasket characteristics affect the sealing behavior significantly. The test results were compared with those of small diameter gasketed flanged connection to highlight the difference of the sealing performance.

scholarly journals Fit Testing Retrofitted Full-Face Snorkel Masks as a Form of Novel Personal Protective Equipment During the COVID-19 Pandemic

2021 ◽  
pp. 1-16
Author(s):  
Stephanie Toigo ◽  
Michel Jacques ◽  
Tarek Razek ◽  
Ewa Rajda ◽  
Sidney Omelon ◽  
...  
Keyword(s):  
Personal Protective Equipment ◽  
Healthcare Workers ◽  
Health Centre ◽  
Disease Outbreaks ◽  
Protective Equipment ◽  
Test Results ◽  
Passing Rate ◽  
Fit Testing ◽  
Full Face ◽  
Medical Grade

ABSTRACT Objective: Bottlenecks in the personal protective equipment (PPE) supply chain have contributed to shortages of PPE during the COVID-19 pandemic, resulting in fractures in the functionality of healthcare systems. This study was conducted with the aim of determining the effectiveness of retrofitted commercial snorkel masks as an alternative respirator for healthcare workers during infectious disease outbreaks. Methods: A retrospective analysis was performed, analyzing qualitative and quantitative fit test results of the retrofitted Aria Ocean Reef® full-face snorkeling mask on healthcare workers at the McGill University Health Centre between April-June 2020. Historical fit test results, using medical-grade respirators, for healthcare workers were also analyzed. Results: During the study period, 71 participants volunteered for fit testing, 60.6% of which were nurses. The overall fit test passing rate using the snorkel mask was 83.1%. Of the participants who did not previously pass fit testing with medical-grade respirators, 80% achieved a passing fit test with the snorkel respirator. Conclusions: The results suggest that this novel respirator may be an effective and feasible alternative solution to address PPE shortages, while still providing healthcare workers with ample protection. Additional robust testing will be required to ensure that respirator fit is maintained, after numerous rounds of disinfection.

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