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Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
For a gasket to seal, certain conditions must be met. There must be enough bolt or clamping force initially to seat the gasket. Then there also must be enough force to keep the gasket tightly clamped as the joint is loaded by pressure.
Energy Transport in Thermal Energy Systems
Published in Steven G. Penoncello, Thermal Energy Systems, 2018
The plates are corrugated with a chevron pattern to enhance turbulence which increases the heat transfer rate. The metal plates are usually cold-stamped. Depending on the temperatures and pressures involved, the gaskets can be made of one of several materials including natural rubber styrene, resin-cured nitrile, silicone rubber, or neoprene. The plates are clamped together in the frame with long bolts as shown in Figure 5.8. Due to its relatively simple construction, it is easily taken apart for maintenance.
Applications: Engineering with Ceramics
Published in David W. Richerson, William E. Lee, Modern Ceramic Engineering, 2018
David W. Richerson, William E. Lee
A seal is an engineered interface designed to prevent leakage at a surface of contact between two materials. When someone asks for an example of a seal, most of us immediately think of one of the thousands of uses of gaskets. Gaskets are typically made of a flexible organic material (such as rubber, polyurethane, Teflon, nylon, or cork) or a soft ductile metal. Under a load, the material deforms and fills spaces that would otherwise be paths for leakage. Good examples are the gaskets in our automobile engines and the gaskets at hose and plumbing junctions. Easily deformed materials are ideal for these seals. However, many applications require a seal between rapidly moving parts where a deformable or soft material would cause too much friction and would wear away quickly. Such a seal is usually referred to as a “face seal.” Other seals must operate at too high a temperature for a polymer or in a severe chemical environment that would rapidly degrade a polymer or metal. These are the cases where a ceramic material is optimum.
Analyses of Critical Hydrogen Enrichment in PWR Containment Compartments
Published in Nuclear Science and Engineering, 2023
E. Schmidt, N. Reinke, M. Freitag, M. Sonnenkalb
The vessel was divided into two compartments, Fig. 2a. The inner compartment consisted of the TTV sump, the inner cylinder, and additional structures. The lower additional structure connected the TTV sump to the inner cylinder, and the upper one extended the inner cylinder to a height of H = 6.895 m and then reduced the diameter by a conical hood that was connected to a DN150-diameter pipe. On top of the latter, an even thinner pipe of either DN50 (53-mm i.d., A = 22 cm2) or DN80 (83-mm i.d., A = 54 cm2) was installed. All connections of parts of the inner compartment were sealed using gasket strips of polytetrafluoroethylene (PTFE). The inner compartment was connected to the annulus by the aforementioned DN50 or DN80 pipe on the upper end at an elevation of H = 8.17 m and by four DN20 pipes that were equally distributed at the circumference at an elevation of H = 1.32 m. The cross-section area of the upper ending pipe had been chosen depending on the expected volume flow rate of the gasses injected into the inner compartment, avoiding backflow within the pipe.
A method to collect representative samples from water-driven percussion drilling techniques: examples from RoXplorer® coiled tubing drill rig
Published in Australian Journal of Earth Sciences, 2022
B. van der Hoek, F. Blaine, D. Giles, C. Tiddy, M. Mostofi, S. Soe
Imbalanced flow between the two sample outlets of the cone splitter was observed in at least seven of the 21 samples where a full PSD duplicate was taken (black dots below the 1:1 line in Figure 7b). The slight bias of fluid flow towards outlet 1 on the cone splitter (Figure 7) is possibly due to partial restriction by silicone sealant from assembly (discovered after the drilling) that reduced the cross-sectional area of outlet 2 within the cone splitter and made outlet 1 the path of least resistance. The use of a rubber gasket in place of silicone sealant during assembly would eliminate this imbalance as well as improve the serviceability of the cone splitter in future deployments. Strong winds from one direction may also have had a significant effect on the performance of the splitter by imparting a pressure imbalance at the outlets. Accounting for the wind in subsequent deployments with the use of a wind shield has improved the performance of the splitter.
Minimally invasive left ventricular assist device implantation: optimizing device design for this approach
Published in Expert Review of Medical Devices, 2020
Anamika Chatterjee, Silvia Mariani, Jasmin S. Hanke, Tong Li, Ali Saad Merzah, Regina Wendl, Axel Haverich, Jan D. Schmitto, Günes Dogan
In parallel to minimally invasive implantation strategies, techniques for LVAD explantation are being developed and new tools are required for this specific procedure [34,42]. So far, a mechanical plug for LVAD explantation has been available for HeartMate II and HVAD. In 2018, a novel custom-made apical ring plug for minimally invasive HeartMate 3 explantation has been described by Ricklefs et al. [43]. This novel customized metal plug has been designed by Croleon Innovation Labs (Kothrud, India), manufactured by INNOVO Solutions GmbH (Wathlingen, Germany) and provided to XXXX for implantation. The INNOVO plug is made of medical grade titanium (Ti6AI4V) and it is coated with titanium plasma spray (TPS) in a thickness of 130 ± 30 µm. The diameter of the plug is 35 mm and its height is 13.5 mm. The plug has been designed to resist a pressure greater than 750 mm Hg and completely seal the HeartMate 3 sewing ring thanks to a silicone gasket [43]. The plug can be inserted into the ventricular coring and sutured onto the sewing ring. This implanting method facilitates minimally invasive approaches, preservation of the pericardium, reduced chance of right heart failure as well as reduced risk of postoperative bleeding. The plug can also facilitate off-pump explantation, as well as LVAD re-implantation. However, this apical ring plug is still an off-label alternative to standard techniques such as ventriculoplasty, and further studies related to its biocompatibility and a CE mark approval study are mandatory to allow a wider use of this tool.