No description available.

At nuclear power plants, electrical valve actuators are important for ensuring that the reactor core is water covered and the pressure in the reactor tank and containment is limited. The electrical actuators are provided with overload protection in case of drawing higher current then the motors are rated for. When safety manoeuvres are needed, the overload protection must not trig and cause the valve to stop before completing the manoeuvre. Analyses have showed that the current settings of the overload protection may cause an illegitimate trig at the worst theoretically possible accident. A new method has been developed with conservative assumptions and applies overload protections for all electrical valve actuators at the three reactors in Forsmark.

No description available.

<p>In this bachelor thesis, diagnostic methods for one of Siemens stem inlet control valves have been developed. The work has taken place during ten weeks at Siemens Industrial Turbomachinery AB in Finspång. The company produce steam- and gas turbines and also provides service and maintenance.</p><p> </p><p>The purpose with this project has been to develop diagnostic methods that oversee the health of the control valves. By using the developed methods you will know when it’s time for maintenance. With these diagnostic methods it’s possible to some degree leave the predetermined maintenance that Siemens uses today on their control valves.</p><p> </p><p>The project has been limited to involve just one of Siemens control valves. The report describes the control valve’s function and the components included in the valve structure. It describes the problems that can occur with the valve and what could be done monitoring it to detect potential failures before they develop into functional failures.</p><p> </p><p>A short description of different measuring equipment and how they work is also included.</p><p> </p><p>Interviews have been conducted at Siemens, at Linköpings University and also with companies that delivers measuring devises. A visit to follow a vibration measurement of a control valve at Idbäcksverket in Nyköping has also taken place. Another tool that has been used in this work is an FMECA that describes errors that may occur with the control valve and what caused them. Books and the internet have also provided necessary facts.</p><p> </p><p>This report presents some recommendations on what to do to monitor health of the control valve and equipment to prevent functional failures. The intention with the report has been to show that the equipment presented here can be used in the future to avoid unnecessary preventive maintenance and eliminate the use of corrective maintenance.</p>

<p>SOMAS är ett tillverkningsföretag i ventilbranschen som tillverkar olika sorters ventiler och ställdon.</p><p>SOMAS vill konstruera en kulventil med en genomloppsdiameter i den standardiserade dimensionen DN500 för att kunna möta kundernas önskemål. Som konstruktionen ser ut idag kommer den bli för stora moment för ställdonen att manövrera kulan om man skalar upp en DN400 kulventil till DN500, varför ny konstruktion behövs.</p><p>Syftet med projektet är att komma med idéer till konstruktionslösningar samt att utreda vilken av dessa som i slutänden är den mest lämpliga.</p><p>Målet är sedan att ta fram ett konstruktionsförslag på det mest lämpliga förslaget.</p><p>3D CAD-modeller gjordes av SOMAS befintliga DN400 kulventil, i Pro/engineer var det sedan lätt att se vilka skillnader på kulans massa de olika modifieringarna gjorde.</p><p>Vi modellerade den befintliga DN400 kulan, kula med kapad botten och tärningsform. När massan på de olika alternativen och gjutgodsets kilopris var känd kunde vi sedan räkna fram prisskillnader i procent mellan de olika alternativen.</p><p>Vi tittade på olika typer av lagringar och delningar av ventilhusen, både med lösa och fasta spindlar.</p><p>Tittade på alternativa tillverkningsmetoder och alternativa material för kulan. Priset på de alternativa materialen jämfördes med standard gjutgods (SS 2343).</p><p>För att få fram storleken på ett säte till en DN500 kulventil gjordes beräkningar på sätestrycket. Ett diagram skapades i Excel över alla SOMAS kulventiler för att få fram ett erforderligt stängningsmoment för en flytande DN500 kula (flytande innebär att kulan inte har någon lagring i botten, se figur 2 sid. 15).</p><p>Kom fram till att vi var tvungna att lagra kulan för att minska stängningsmomentet, beräknade då lagringstryck samt skjuvspänning i axeltapparna för att få fram erforderlig längd samt diameter på dessa.</p><p>Räknade på hur stor momentminskningen blev om man lagrade kulan istället för att ha den flytande.</p><p>Den mest lämpliga konstruktionen visade sig vara en tärningsformad kula lagrad med ingjutna fasta tappar och urfrästa lagerhus i det diagonalt delade ventilhuset.</p> / <p>SOMAS are a producing company within the valve area and are producing different kinds of valves and actuators.</p><p>SOMAS wants to design a ball valve with the standardized flow diameter DN500 to meet the market demands. Today’s construction if it's up scaled from a DN400 ball valve to DN500 gives to much torque for the actuator to handle the turning of the ball, therefore a new design is needed.</p><p>Our task is to come up with new design ideas. In addition, find out which one of those are the most suitable.</p><p>The goal is to come up with at construction suggestion of the most suitable construction.</p><p>3D CAD-models of SOMAS DN400 ball valve were made at which some modifications were made. It was easy to see the variation in the ball mass when a modification was made in Pro/engineer. We made models of the existing DN400 ball, ball with the bottom cut of and dice shaped ball. When we knew the mass of the alternative shapes and the price of the castings, we calculated the price differences in percent between the different alternatives.</p><p>We looked at different types of bearings and separations of the valve house, both with loose and fastened axels.</p><p>Looked at alternative manufacturing methods and alternative materials for the ball. The price on the alternative materials where compared with standard castings (SS 2343).</p><p>To come up with a size for the seat to a DN500 ball valve, calculations of the seat pressure was made. A diagram over all SOMAS ball valves was made in Excel to calculate necessary closing torque for a floating DN500 ball (floating means that the ball does not have a bearing in the bottom look, at figur 2 page 15).</p><p>We conclude that we had to mount the ball in bearings to minimize the torque. Calculated bearing pressure and shear in the shafts to come up with required length and diameter of those.</p><p>Computed on how much the torque reduction was if the ball was mounted in bearings versus floating.</p><p>We found that a dice shaped ball with bearings, cast axels, milled bearing houses and diagonally split valve house is the most suitable.</p>

In this bachelor thesis, diagnostic methods for one of Siemens stem inlet control valves have been developed. The work has taken place during ten weeks at Siemens Industrial Turbomachinery AB in Finspång. The company produce steam- and gas turbines and also provides service and maintenance.   The purpose with this project has been to develop diagnostic methods that oversee the health of the control valves. By using the developed methods you will know when it’s time for maintenance. With these diagnostic methods it’s possible to some degree leave the predetermined maintenance that Siemens uses today on their control valves.   The project has been limited to involve just one of Siemens control valves. The report describes the control valve’s function and the components included in the valve structure. It describes the problems that can occur with the valve and what could be done monitoring it to detect potential failures before they develop into functional failures.   A short description of different measuring equipment and how they work is also included.   Interviews have been conducted at Siemens, at Linköpings University and also with companies that delivers measuring devises. A visit to follow a vibration measurement of a control valve at Idbäcksverket in Nyköping has also taken place. Another tool that has been used in this work is an FMECA that describes errors that may occur with the control valve and what caused them. Books and the internet have also provided necessary facts.   This report presents some recommendations on what to do to monitor health of the control valve and equipment to prevent functional failures. The intention with the report has been to show that the equipment presented here can be used in the future to avoid unnecessary preventive maintenance and eliminate the use of corrective maintenance.

SOMAS är ett tillverkningsföretag i ventilbranschen som tillverkar olika sorters ventiler och ställdon. SOMAS vill konstruera en kulventil med en genomloppsdiameter i den standardiserade dimensionen DN500 för att kunna möta kundernas önskemål. Som konstruktionen ser ut idag kommer den bli för stora moment för ställdonen att manövrera kulan om man skalar upp en DN400 kulventil till DN500, varför ny konstruktion behövs. Syftet med projektet är att komma med idéer till konstruktionslösningar samt att utreda vilken av dessa som i slutänden är den mest lämpliga. Målet är sedan att ta fram ett konstruktionsförslag på det mest lämpliga förslaget. 3D CAD-modeller gjordes av SOMAS befintliga DN400 kulventil, i Pro/engineer var det sedan lätt att se vilka skillnader på kulans massa de olika modifieringarna gjorde. Vi modellerade den befintliga DN400 kulan, kula med kapad botten och tärningsform. När massan på de olika alternativen och gjutgodsets kilopris var känd kunde vi sedan räkna fram prisskillnader i procent mellan de olika alternativen. Vi tittade på olika typer av lagringar och delningar av ventilhusen, både med lösa och fasta spindlar. Tittade på alternativa tillverkningsmetoder och alternativa material för kulan. Priset på de alternativa materialen jämfördes med standard gjutgods (SS 2343). För att få fram storleken på ett säte till en DN500 kulventil gjordes beräkningar på sätestrycket. Ett diagram skapades i Excel över alla SOMAS kulventiler för att få fram ett erforderligt stängningsmoment för en flytande DN500 kula (flytande innebär att kulan inte har någon lagring i botten, se figur 2 sid. 15). Kom fram till att vi var tvungna att lagra kulan för att minska stängningsmomentet, beräknade då lagringstryck samt skjuvspänning i axeltapparna för att få fram erforderlig längd samt diameter på dessa. Räknade på hur stor momentminskningen blev om man lagrade kulan istället för att ha den flytande. Den mest lämpliga konstruktionen visade sig vara en tärningsformad kula lagrad med ingjutna fasta tappar och urfrästa lagerhus i det diagonalt delade ventilhuset. / SOMAS are a producing company within the valve area and are producing different kinds of valves and actuators. SOMAS wants to design a ball valve with the standardized flow diameter DN500 to meet the market demands. Today’s construction if it's up scaled from a DN400 ball valve to DN500 gives to much torque for the actuator to handle the turning of the ball, therefore a new design is needed. Our task is to come up with new design ideas. In addition, find out which one of those are the most suitable. The goal is to come up with at construction suggestion of the most suitable construction. 3D CAD-models of SOMAS DN400 ball valve were made at which some modifications were made. It was easy to see the variation in the ball mass when a modification was made in Pro/engineer. We made models of the existing DN400 ball, ball with the bottom cut of and dice shaped ball. When we knew the mass of the alternative shapes and the price of the castings, we calculated the price differences in percent between the different alternatives. We looked at different types of bearings and separations of the valve house, both with loose and fastened axels. Looked at alternative manufacturing methods and alternative materials for the ball. The price on the alternative materials where compared with standard castings (SS 2343). To come up with a size for the seat to a DN500 ball valve, calculations of the seat pressure was made. A diagram over all SOMAS ball valves was made in Excel to calculate necessary closing torque for a floating DN500 ball (floating means that the ball does not have a bearing in the bottom look, at figur 2 page 15). We conclude that we had to mount the ball in bearings to minimize the torque. Calculated bearing pressure and shear in the shafts to come up with required length and diameter of those. Computed on how much the torque reduction was if the ball was mounted in bearings versus floating. We found that a dice shaped ball with bearings, cast axels, milled bearing houses and diagonally split valve house is the most suitable.

<p>This report is a first practical study of micro valves for hydraulics, manufactured by Microstaq Inc. who uses, for hydraulics, new materials and new actuating technologies. The purpose is to evaluate if, in the future, there is any possibility of complementing or exchanging the classical use of electro magnetic solenoids in electro hydraulic applications with this new technology. The valves studied are of MEMS-type (Micro Electro Mechanical Systems), which are etched out of silicon and has an electro thermic actuation. During the study it showed that this new valve technology had some teething troubles. The valves had proplems managing high pressure drops, both regarding strength of materials and performance. If you let the manufacturers further develop this technology there are great potentials for using this in future hydraulic systems.</p>

This report is a first practical study of micro valves for hydraulics, manufactured by Microstaq Inc. who uses, for hydraulics, new materials and new actuating technologies. The purpose is to evaluate if, in the future, there is any possibility of complementing or exchanging the classical use of electro magnetic solenoids in electro hydraulic applications with this new technology. The valves studied are of MEMS-type (Micro Electro Mechanical Systems), which are etched out of silicon and has an electro thermic actuation. During the study it showed that this new valve technology had some teething troubles. The valves had proplems managing high pressure drops, both regarding strength of materials and performance. If you let the manufacturers further develop this technology there are great potentials for using this in future hydraulic systems.

För att se till att en produkt ständigt är konkurrenskraftig krävs en kontinuerlig utveckling av densamma. Därför har detta examensarbete undersökt möjligheterna att öka flödes- och sprängtrycksprestandan hos en av Rototilts 1/2"-hydrauliska snabbkopplingsventiler. Arbetet behandlar planering, behovsanalys, konceptgenerering och utvärdering. För att kunna välja det mest lämpade konceptet simulerades både flöde- och hållfasthet med FEM-analyser. Det mest lovande konceptet vidareutvecklades ytterligare och underlag för tillverkning av en prototyp skapades. Denna prototyp tillverkades sedan och utvärderades med två tester. Simuleringarna visade att hållfastheten mot sprängning skulle förbättras med minst 5-6 % och flödesprestandan skulle öka med 15 %. Detta visade sig stämma ganska bra överens med verkligheten. Kopplingen kunde motstå 11-48 % högre tryck och flödet ökade med 15 % jämfört med nuvarande version. Däremot så kunde inte simuleringen påvisa små skillnader i flöde. De mest lovande koncept förutspåddes ha 2 % lägre tryckfall än ett av Rototilts tidigare koncept, men visade sig ha 3 % sämre flöde. Sammantaget kan man genom smart utformning och simuleringar åstadkomma signifikant bättre prestanda hos en komponent, men att precisionen i simuleringsresultat alltid måste beaktas. Den här förbättrade flödesprestandan leder till minskad energiförbrukning, vilket är bättre både för kundens plånbok och för miljön.