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 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.

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.

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.

scholarly journals Investigation on Physicochemical Properties of Wastewater Grown Microalgae Methyl Ester and its Effects on CI Engine

2020 ◽  
Vol 24 (1) ◽  
pp. 72-87 ◽  
Author(s):  
Sara Tayari ◽  
Reza Abedi ◽  
Ali Abedi
Keyword(s):  
Methyl Ester ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Biodiesel Production ◽  
Emissions Reduction ◽  
Test Results ◽  
Main Fatty Acid ◽  
Ci Engine ◽  
Hc Emissions ◽  
A Minor

AbstractMicroalgae have been mentioned as a promising feedstock for biodiesel production. In this study, microalgae Chlorella vulgaris (MCV) was cultivated in a bioreactor with wastewater. After biodiesel production from MCV oil via transesterification reaction, chemical and physical properties of MCV methyl ester were evaluated with regular diesel and ASTM standard. Besides, engine performance and exhaust emissions of CI engine fuelled with the blends of diesel-biodiesel were measured. The GC-MS analysis showed that oleic and linoleic acids were the main fatty acid compounds in the MCV methyl ester. Engine test results revealed that the use of biodiesel had led to a major decrease in CO and HC emissions and a modest reduction in CO2 emissions, whereas there was a minor increase in NOx emissions. Furthermore, there was a slight decrease in the engine power and torque while a modest increase in brake specific fuel consumption which are acceptable due to exhaust emissions reduction. The experimental results illustrate considerable capabilities of applied MVC biodiesel as an alternative fuel in diesel engines to diminish the emissions.

A Collaborative Approach to Achieving a Gas-Tight Seal Using Expanded Polytetrafluorethylene (ePTFE) Gaskets in a Fiberglass-Reinforced Plastic (FRP) Lap-Joint Flanges

2012 ◽  
Author(s):  
John Czerwinski ◽  
Vijay K. Garikipati ◽  
Charlene N. Jones ◽  
Brad Pires ◽  
John P. Ludman ◽  
...  
Keyword(s):  
Collaborative Approach ◽  
Lap Joint ◽  
Fugitive Emissions ◽  
Plant Operator ◽  
Chemical Process Industry ◽  
Reinforced Plastic ◽  
Piping Systems ◽  
Bolted Flange ◽  
Gas Tight

The work presented here is a collaborative approach to achieving a reliable gas tight seal in fiberglass reinforced plastic (FRP) flanged joints using expanded polytetrafluoroethylene (ePTFE) gaskets. There are many advantages to incorporating FRP flanged piping systems in today’s chemical process industry plant build. As regulations on reliability and fugitive emissions become stricter, it is more important than ever to eliminate possible damage and leak paths at the flanged connections in these systems. This paper details a case study on a collaboration between a chemical plant operator (end user), an ePTFE gasket manufacturer, and a FRP piping original equipment manufacturer. Over a twenty-four month period a FRP flanged system was designed and validated using a custom FRP stub and ring, also known as a lap joint, flange with an ePTFE gasket. The result was the development of a FRP bolted flange system that successfully achieved a reliable gas tight seal for aggressive chemicals. Beginning with a theoretical model and ending with experimental lab analyses, the conclusive results are included herein.

Theoretical Calculation and Experimental Research on Sequential Turbocharging of a Marine Diesel Engine

2011 ◽  
Vol 305 ◽  
pp. 416-422
Author(s):  
Peng Qi Zhang ◽  
Qing Lin He ◽  
Yin Yan Wang
Keyword(s):  
Diesel Engine ◽  
Theoretical Calculation ◽  
Experimental Research ◽  
Marine Diesel Engine ◽  
Test Results ◽  
Low Load ◽  
Marine Diesel ◽  
Working Principle ◽  
Test Result

The paper introduces the working principle of the sequential turbo-charging (STC) system of multi-turbocharger. To improve low-load performance and operating economy of the 234V12 diesel engine, a STC system of multi-turbocharger for the diesel engine was designed. Theoretical calculation and experimental research was done on this improved marine diesel engine. Then, a 3-phase STC system is presented by analyzing and comparing the test result and the switching boundary of this system is confirmed. The test results show that the low-load performance is improved obviously by use of multi-turbocharger STC system.

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.

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