The company Somas, Säffle, has assigned Fredrik Kjellin the project of finding out how ?KVTF DN250?, one of their own valves, reacts on cutting forces under production. They wish to know if and then how much it?s possible to minimize the wall thickness of the valve with neither plastic nor to big elastic deformations caused by processing.The most critical processes have been identified as rough lathing. The study has shown that the marginal for a wall thickness of two millimeters, to fall short of the yield stress in the most critical process, is good.

The purpose of this work is to find out if the suctionvalve to the salivaejector for dental equipment in a simple way can be improved or if a new design is needed. The result of the examination of the suctionvalve shows that the friction between the piston and the seal is high and that this causes the valve in a few cases sheaves. The study concluded that only small changes in material or detail, improve the component..

The purpose of this work is to find out if the suctionvalve to the salivaejector for dental equipment in a simple way can be improved or if a new design is needed. The result of the examination of the suctionvalve shows that the friction between the piston and the seal is high and that this causes the valve in a few cases sheaves. The study concluded that only small changes in material or detail, improve the component..

Den här rapporten undersöker hur strömningsmotståndet och tätheten i en vridspjällsventil påverkas av form på spindel och spjäll. I rapporten undersök också storleken på det hydrodynamiska moment som fluiden utövar på ventilens spindel.Rapporten utgår från en referensventil som ingår i SOMAS (SOMAS Instrument AB) produktsortiment och är av typen MTV med dimensionen DN 150. Modifieringar görs på referensventilens spindel och spjäll. Som mått på strömningsmotstånd används ventilens egenkarakteristik och som mått på täthet används storleken på den elastiska deformationen på spindel och spjäll då ventilen är stängd. Kraven som ställs då spindel och spjäll modifieras är att spindeln ska vara delad, spindel och spjäll ska gå att montera in i referensventilens Ventilhus och referensventilen skall vara tät då ett modifierat spjäll med delad spindel monterats in i referensventilen.För att skatta egenkarakteristik, hydrodynamiskt moment och täthet har CFD- och strukturmodeller byggts upp i COMSOL Multiphysics version 4.0a.

AbstractThis is a thesis done in cooperation with the firm Somas and University of Karlstad. The project is an independent final examination part of the program in Innovation and DesignEngineering comprising 22.5 points, and performed by Mia Myrén Zreloff during spring term 2012. In parallel and collaboration, Fredrik Kjellin performs a similar job for the same company and with the same extent, but for the Program in Mechanical Engineering.The client and supervisor at the company have been Magnus Jansson and Anders Josefsson. At Karlstad University has technical supervisor been Hans Johansson, and in the design- and development process it was Monica Jakobsson. Examiner has been Fredrik Thuvander, professor in the Faculty of Technology and Science at Karlstad University.The mission has been to make a basis work for the company's own development and make a computational model to calculate, visualize and implement materials and other solutions in the manufacture of the company's ball valves.The project has undergone three major phases that included thorough study of the company, production, the problem and product.