Vacuum gauges and vacuum valves are important instruments used to measure and control pressure and gas flow in vacuum systems. There are several types of vacuum gauges that measure different pressure ranges, including mechanical gauges, U-tube manometers, McLeod gauges, and capacitance manometers. The main types of vacuum valves are angle valves, in-line valves, ball valves, and butterfly valves. Vacuum valves serve three main functions: to isolate vacuum volumes from pumps, control gas flow to achieve a particular pressure, and enable transfer of objects between vacuum volumes.
This document discusses the thermo-mechanical processing of titanium alloys. It begins with an abstract describing titanium alloy properties and applications in aerospace and medical fields. It then covers titanium crystal structures, properties, advantages, classifications including commercially pure, alpha, near-alpha, alpha-beta and beta alloys. Heat treatments including annealing, quenching and aging are described for different alloy types. Microstructures, properties and applications of various alloys are also summarized.
This document provides information about the Casting, Forming & Welding (ME31007) course offered by the Department of Mechanical Engineering. It outlines the course content, schedule, assessment details and references. The course covers casting, forming and welding topics over 19 hours. Welding topics include introduction, processes, energy sources, fluxes, welding arc physics, heat flow, joint design, defects, metallurgy and brazing. Assessment is based on end semester exam, mid semester exam, two class tests and assignments. Lectures cover welding science, heat transfer mechanisms, microstructural zones, continuity mechanisms and specific processes like oxy-fuel gas welding.
This document discusses liquid penetrant inspection (LPI), a non-destructive testing method used to locate surface-breaking defects. It describes the 6 key steps of LPI: 1) pre-cleaning the surface, 2) applying penetrant, 3) removing excess penetrant, 4) applying developer, 5) inspection under UV or white light, and 6) post-cleaning. It also covers the principles of LPI, properties required for good penetrants and developers, types of penetrants, and provides examples of LPI applications and limitations.
This document discusses phase diagrams and how they can be used to determine information about alloy mixtures. It describes how cooling curves can be used to identify phase change temperatures. Two key rules are discussed: 1) the lever rule, which uses tie lines to determine phase compositions, and 2) another lever rule which uses tie lines and their relative lengths to determine phase amounts. Different types of phase diagrams are shown including ones for complete solubility, partial solubility, and eutectic systems. The document explains how to interpret features and apply the rules to extract information from phase diagrams.
Taphole clay for blast furnace operationHarvey Yang
This document discusses taphole clay and blast furnace operation from Sheng Iron Refractories. It covers three parts: (1) the importance of proper tapping times to safely remove molten iron and slag, (2) operation notices to maintain a safe taphole, including fully draining before plugging and avoiding humidity, and (3) factors to consider when choosing a quality taphole clay product, such as long stable taphole length and minimization of spraying during operation.
This document provides information about vacuum systems. It begins by defining vacuum and discussing the different levels or classifications of vacuum including rough, high, and ultra-high vacuum. It then explains various vacuum pump technologies used for different pressure ranges like rotary pumps, diffusion pumps, and cryopumps. It also covers vacuum measurement tools known as vacuum gauges and issues like leaks in vacuum systems. Overall, the document serves as an introduction to key concepts and components in vacuum technology.
Vacuum gauges and vacuum valves are important instruments used to measure and control pressure and gas flow in vacuum systems. There are several types of vacuum gauges that measure different pressure ranges, including mechanical gauges, U-tube manometers, McLeod gauges, and capacitance manometers. The main types of vacuum valves are angle valves, in-line valves, ball valves, and butterfly valves. Vacuum valves serve three main functions: to isolate vacuum volumes from pumps, control gas flow to achieve a particular pressure, and enable transfer of objects between vacuum volumes.
This document discusses the thermo-mechanical processing of titanium alloys. It begins with an abstract describing titanium alloy properties and applications in aerospace and medical fields. It then covers titanium crystal structures, properties, advantages, classifications including commercially pure, alpha, near-alpha, alpha-beta and beta alloys. Heat treatments including annealing, quenching and aging are described for different alloy types. Microstructures, properties and applications of various alloys are also summarized.
This document provides information about the Casting, Forming & Welding (ME31007) course offered by the Department of Mechanical Engineering. It outlines the course content, schedule, assessment details and references. The course covers casting, forming and welding topics over 19 hours. Welding topics include introduction, processes, energy sources, fluxes, welding arc physics, heat flow, joint design, defects, metallurgy and brazing. Assessment is based on end semester exam, mid semester exam, two class tests and assignments. Lectures cover welding science, heat transfer mechanisms, microstructural zones, continuity mechanisms and specific processes like oxy-fuel gas welding.
This document discusses liquid penetrant inspection (LPI), a non-destructive testing method used to locate surface-breaking defects. It describes the 6 key steps of LPI: 1) pre-cleaning the surface, 2) applying penetrant, 3) removing excess penetrant, 4) applying developer, 5) inspection under UV or white light, and 6) post-cleaning. It also covers the principles of LPI, properties required for good penetrants and developers, types of penetrants, and provides examples of LPI applications and limitations.
This document discusses phase diagrams and how they can be used to determine information about alloy mixtures. It describes how cooling curves can be used to identify phase change temperatures. Two key rules are discussed: 1) the lever rule, which uses tie lines to determine phase compositions, and 2) another lever rule which uses tie lines and their relative lengths to determine phase amounts. Different types of phase diagrams are shown including ones for complete solubility, partial solubility, and eutectic systems. The document explains how to interpret features and apply the rules to extract information from phase diagrams.
Taphole clay for blast furnace operationHarvey Yang
This document discusses taphole clay and blast furnace operation from Sheng Iron Refractories. It covers three parts: (1) the importance of proper tapping times to safely remove molten iron and slag, (2) operation notices to maintain a safe taphole, including fully draining before plugging and avoiding humidity, and (3) factors to consider when choosing a quality taphole clay product, such as long stable taphole length and minimization of spraying during operation.
This document provides information about vacuum systems. It begins by defining vacuum and discussing the different levels or classifications of vacuum including rough, high, and ultra-high vacuum. It then explains various vacuum pump technologies used for different pressure ranges like rotary pumps, diffusion pumps, and cryopumps. It also covers vacuum measurement tools known as vacuum gauges and issues like leaks in vacuum systems. Overall, the document serves as an introduction to key concepts and components in vacuum technology.
The document discusses materials at high temperatures and creep. It describes how microstructure and mechanical properties change at high temperatures, including grain growth, vacancy formation, and increased mobility of dislocations and atoms. It then focuses on creep, which is the time-dependent deformation of materials under constant load at high temperatures. The typical creep curve is presented, showing the stages of instantaneous deformation, primary creep, secondary creep, and tertiary creep. Parameters that characterize creep behavior like steady-state creep rate and time to rupture are discussed. The effects of stress and temperature on creep are described. Models for predicting creep behavior like the Larson-Miller relation are presented. Creep damage mechanisms involving void formation and linkage are described. The document concludes
Submerged arc welding (SAW) is a process where the arc and molten pool are concealed under a layer of granular flux. An electric current is passed between the continuously fed electrode wire and workpiece, heating them to fuse the metals. Key advantages include high quality welds, high deposition rates, and the ability to weld thick plates. Applications include boilers, pressure vessels, ships, and structural fabrication.
This document provides an overview of magnetic particle inspection (MPI), a non-destructive testing method used to detect surface and near-surface defects in ferromagnetic materials. It describes how MPI works by magnetizing a part and applying iron particles that are attracted to discontinuities, outlines the basic MPI procedure, and discusses factors like magnetic field direction and interpretation of indications. Examples of MPI indications on different components are also shown.
This document provides information about liquid penetrant testing (LPT), including the inspection procedure, properties of liquid penetrants, types of penetrants and developers, and interpretation of results. LPT uses capillary action to draw penetrants into surface-breaking defects, where they are extracted and made visible by developers. It can detect a variety of flaw types in both metallic and non-metallic materials, has high sensitivity, and is a low-cost and portable method. However, it is limited to surface and near-surface defects. Proper cleaning and chemical handling are also required.
Type of threads - How to identify threadsTeesing BV
This document provides information about different types of threads, including metric (M), BSPP, BSPT, NPT, UNC, and UNF threads. It discusses the key characteristics that define each type of thread such as diameter, pitch, taper angle, and flank angle. Examples are given for various common thread sizes of each type. In addition, the document addresses frequently asked questions about identifying threads, determining if threads are tapered or parallel, differences between BSPP and BSPT, thread sealing, and thread compatibility.
This document provides an overview of penetrant testing (PT), a nondestructive testing method. PT involves applying a penetrant that seeps into surface-breaking defects, removing excess penetrant, and using a developer to draw the penetrant out of defects and make indications visible. The key steps are cleaning, applying penetrant, removing excess penetrant, applying developer, inspecting, and post-cleaning. PT can detect cracks, pores, and other discontinuities in many materials, and has advantages of being easy to use and able to inspect large areas, though it is limited to surface defects.
The document discusses Magnetic Particle Inspection (MPI), including the principles, methods, and basic procedure. MPI uses magnetic fields to detect discontinuities in ferromagnetic materials. A component is magnetized, then magnetic particles are applied to reveal defects that interrupt magnetic field flow. Methods to introduce magnetic fields include direct and indirect techniques using things like electromagnets, coils, and magnetic yokes. Interpretation of particle indications is required to identify relevant defects.
Liquid penetrant testing is a non-destructive testing method used to reveal surface discontinuities in materials. It works by applying a penetrant that seeps into flaws, removing excess penetrant, and then using a developer to draw the penetrant out of flaws so they are visible. The general steps are surface preparation to clean the part, applying penetrant and letting it dwell, removing excess penetrant, applying developer, and inspecting under light to detect any indications of flaws. It is a sensitive method suitable for many materials but can only detect surface-breaking defects.
Liquid Penetrant Testing - Principles, types and properties of liquid penetrants, developers, advantages and limitations of various methods, Testing Procedure, Interpretation of results. Magnetic Particle Testing- Theory of magnetism, inspection materials Magnetisation methods, Interpretation and evaluation of test indications, Principles and methods of demagnetization, Residual magnetism
Vapor Deposition Pattern Transfer discusses various deposition techniques including physical vapor deposition (PVD) methods like thermal evaporation and sputtering, as well as chemical vapor deposition (CVD). It describes the basic processes, parameters, and applications of these techniques for depositing thin films including considerations for step coverage, reaction mechanisms, and mass transport effects.
The document summarizes three regimes of boiling - purely convective boiling where liquid slowly rises from the heated surface, nucleate boiling where vapor bubbles form and detach from nucleation sites on the surface, and film boiling where a vapor film covers the entire surface. It also discusses two types of condensation - film wise where a continuous liquid film forms, and drop wise where small liquid droplets form randomly. Finally, it introduces heat exchangers as devices that transfer heat between two fluids through a separating solid barrier.
Vacuum is the reduction of air pressure in a container using vacuum pumps. Different types of pumps are used to obtain different levels of vacuum pressure ranging from rough vacuum to ultrahigh vacuum. Rotary pumps are used for rough vacuum between 760 Torr to 10-4 Torr. Diffusion pumps are used for higher vacuums from 10-4 Torr to 10-10 Torr using fluid entrainment. Sputter ion pumps provide ultrahigh vacuum through ionization and trapping of gas atoms without fluids or moving parts. Vacuum is measured using gauges like the Pirani gauge for rough vacuums from 0.5 Torr to 10-3 Torr based on thermal conductivity, or ion
Non-destructive testing (NDT) methods like dye penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography testing are used to locate defects in metal components without damaging them. The document discusses the basic principles, procedures, advantages, limitations of these various NDT methods. It also compares ultrasonic testing and radiography testing, noting their relative capabilities in flaw detection and operational safety requirements. The conclusion emphasizes the importance of NDT for industrial inspection and maintenance.
The document discusses methods for determining particle size from SEM micrographs and XRD data. It provides background on SEM, describing how it can be used to obtain particle morphology, size, and other information from micrographs. It also discusses how to measure particle size manually from micrographs and using ImageJ software. For XRD, it describes how the Scherrer equation can be used to calculate crystallite size from peak broadening in XRD patterns. Examples of SEM micrographs and XRD patterns are provided to illustrate these techniques.
This document provides an overview of TIG, plasma arc, and MIG welding processes for aluminum. It describes the principles, equipment, parameters, and macrostructure outcomes of each process. The objectives are to explain TIG, plasma arc, and MIG welding and their modifications for aluminum, how welding parameters influence macrostructure, and the choice of parameters. It requires a general engineering background and basic electrical engineering knowledge. The document was created in 1994 and contains 47 figures to illustrate the concepts discussed over 36 pages.
This document provides an overview of liquid penetrant inspection (LPI), a nondestructive testing method used to detect surface-breaking flaws. It discusses how LPI works by drawing colored dye into flaws via capillarity, and the basic six-step LPI process: 1) cleaning, 2) penetrant application, 3) excess penetrant removal, 4) developer application, 5) inspection, and 6) post-cleaning. The document also covers penetrant and developer materials and their properties, factors that influence the process, and advantages and limitations of LPI for nondestructive surface flaw detection.
Fatigue is the progressive and localized structural damage that occurs when a material is subjected to fluctuating stresses that are less than the static yield strength of the material. It accounts for about 90% of industrial failures. Fatigue occurs in five stages: cyclic plastic deformation, crack initiation, crack propagation, propagation of macro cracks, and final fracture. It is characterized by beach marks and a rough, brittle fracture surface. Fatigue life can be represented using an S-N curve which plots the maximum stress versus the number of cycles to failure. The fatigue limit or endurance limit is identified as the stress below which a material can undergo any number of stress cycles without failure.
Lubrication is important to reduce friction between moving parts and prevent damage. Lubricants like oils minimize friction and energy loss from rubbing surfaces. The main functions of lubricating oil are to reduce friction and wear, act as a coolant, reduce noise, provide sealing and cushioning. Good lubricants have properties like high viscosity index, chemical and thermal stability, cleanliness and resistance to extreme pressure. Lubricants can be mineral oils from petroleum, synthetic or animal/vegetable oils, and come as liquids, greases or solids. Lubrication systems include splash, pressure and dry sump to deliver oil under pressure to engine components like bearings and gears.
Thermographic testing uses infrared cameras to detect differences in surface temperatures that may indicate issues. It allows non-contact inspection of electrical equipment, buildings, industrial processes, and more. Key advantages are that it is non-destructive, fast, and can detect problems like loose connections, moisture ingress, insulation issues, and more from a distance. Operator experience is important to properly set up the infrared camera and interpret thermal images.
This document provides an overview of safe handling practices for compressed gases. It defines compressed gases and lists various gas properties like being under high pressure, toxic, corrosive, or flammable. The document outlines identification markings on gas cylinders and regulations for transportation, storage, and use. It describes hazards of compressed gases and emphasizes treating all cylinders with care. The document also reviews functions of pressure regulators, safety devices, and developing an emergency plan for gas releases.
Vacuum is the reduction of air pressure in a container using vacuum pumps. Different types of pumps are used to obtain different levels of vacuum pressure ranging from rough vacuum to ultrahigh vacuum. Rotary pumps are used for rough vacuum between 760 Torr to 10-4 Torr. Diffusion pumps are used for higher vacuums from 100mT to 10-10 mTorr using fluid entrainment. Sputter ion pumps provide ultrahigh vacuum through ionization and trapping of gas atoms without fluids or moving parts. Vacuum is measured using gauges like the Pirani gauge for rough vacuums from 0.5 Torr to 10-3 Torr based on thermal conductivity, and ion gaug
The document discusses materials at high temperatures and creep. It describes how microstructure and mechanical properties change at high temperatures, including grain growth, vacancy formation, and increased mobility of dislocations and atoms. It then focuses on creep, which is the time-dependent deformation of materials under constant load at high temperatures. The typical creep curve is presented, showing the stages of instantaneous deformation, primary creep, secondary creep, and tertiary creep. Parameters that characterize creep behavior like steady-state creep rate and time to rupture are discussed. The effects of stress and temperature on creep are described. Models for predicting creep behavior like the Larson-Miller relation are presented. Creep damage mechanisms involving void formation and linkage are described. The document concludes
Submerged arc welding (SAW) is a process where the arc and molten pool are concealed under a layer of granular flux. An electric current is passed between the continuously fed electrode wire and workpiece, heating them to fuse the metals. Key advantages include high quality welds, high deposition rates, and the ability to weld thick plates. Applications include boilers, pressure vessels, ships, and structural fabrication.
This document provides an overview of magnetic particle inspection (MPI), a non-destructive testing method used to detect surface and near-surface defects in ferromagnetic materials. It describes how MPI works by magnetizing a part and applying iron particles that are attracted to discontinuities, outlines the basic MPI procedure, and discusses factors like magnetic field direction and interpretation of indications. Examples of MPI indications on different components are also shown.
This document provides information about liquid penetrant testing (LPT), including the inspection procedure, properties of liquid penetrants, types of penetrants and developers, and interpretation of results. LPT uses capillary action to draw penetrants into surface-breaking defects, where they are extracted and made visible by developers. It can detect a variety of flaw types in both metallic and non-metallic materials, has high sensitivity, and is a low-cost and portable method. However, it is limited to surface and near-surface defects. Proper cleaning and chemical handling are also required.
Type of threads - How to identify threadsTeesing BV
This document provides information about different types of threads, including metric (M), BSPP, BSPT, NPT, UNC, and UNF threads. It discusses the key characteristics that define each type of thread such as diameter, pitch, taper angle, and flank angle. Examples are given for various common thread sizes of each type. In addition, the document addresses frequently asked questions about identifying threads, determining if threads are tapered or parallel, differences between BSPP and BSPT, thread sealing, and thread compatibility.
This document provides an overview of penetrant testing (PT), a nondestructive testing method. PT involves applying a penetrant that seeps into surface-breaking defects, removing excess penetrant, and using a developer to draw the penetrant out of defects and make indications visible. The key steps are cleaning, applying penetrant, removing excess penetrant, applying developer, inspecting, and post-cleaning. PT can detect cracks, pores, and other discontinuities in many materials, and has advantages of being easy to use and able to inspect large areas, though it is limited to surface defects.
The document discusses Magnetic Particle Inspection (MPI), including the principles, methods, and basic procedure. MPI uses magnetic fields to detect discontinuities in ferromagnetic materials. A component is magnetized, then magnetic particles are applied to reveal defects that interrupt magnetic field flow. Methods to introduce magnetic fields include direct and indirect techniques using things like electromagnets, coils, and magnetic yokes. Interpretation of particle indications is required to identify relevant defects.
Liquid penetrant testing is a non-destructive testing method used to reveal surface discontinuities in materials. It works by applying a penetrant that seeps into flaws, removing excess penetrant, and then using a developer to draw the penetrant out of flaws so they are visible. The general steps are surface preparation to clean the part, applying penetrant and letting it dwell, removing excess penetrant, applying developer, and inspecting under light to detect any indications of flaws. It is a sensitive method suitable for many materials but can only detect surface-breaking defects.
Liquid Penetrant Testing - Principles, types and properties of liquid penetrants, developers, advantages and limitations of various methods, Testing Procedure, Interpretation of results. Magnetic Particle Testing- Theory of magnetism, inspection materials Magnetisation methods, Interpretation and evaluation of test indications, Principles and methods of demagnetization, Residual magnetism
Vapor Deposition Pattern Transfer discusses various deposition techniques including physical vapor deposition (PVD) methods like thermal evaporation and sputtering, as well as chemical vapor deposition (CVD). It describes the basic processes, parameters, and applications of these techniques for depositing thin films including considerations for step coverage, reaction mechanisms, and mass transport effects.
The document summarizes three regimes of boiling - purely convective boiling where liquid slowly rises from the heated surface, nucleate boiling where vapor bubbles form and detach from nucleation sites on the surface, and film boiling where a vapor film covers the entire surface. It also discusses two types of condensation - film wise where a continuous liquid film forms, and drop wise where small liquid droplets form randomly. Finally, it introduces heat exchangers as devices that transfer heat between two fluids through a separating solid barrier.
Vacuum is the reduction of air pressure in a container using vacuum pumps. Different types of pumps are used to obtain different levels of vacuum pressure ranging from rough vacuum to ultrahigh vacuum. Rotary pumps are used for rough vacuum between 760 Torr to 10-4 Torr. Diffusion pumps are used for higher vacuums from 10-4 Torr to 10-10 Torr using fluid entrainment. Sputter ion pumps provide ultrahigh vacuum through ionization and trapping of gas atoms without fluids or moving parts. Vacuum is measured using gauges like the Pirani gauge for rough vacuums from 0.5 Torr to 10-3 Torr based on thermal conductivity, or ion
Non-destructive testing (NDT) methods like dye penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography testing are used to locate defects in metal components without damaging them. The document discusses the basic principles, procedures, advantages, limitations of these various NDT methods. It also compares ultrasonic testing and radiography testing, noting their relative capabilities in flaw detection and operational safety requirements. The conclusion emphasizes the importance of NDT for industrial inspection and maintenance.
The document discusses methods for determining particle size from SEM micrographs and XRD data. It provides background on SEM, describing how it can be used to obtain particle morphology, size, and other information from micrographs. It also discusses how to measure particle size manually from micrographs and using ImageJ software. For XRD, it describes how the Scherrer equation can be used to calculate crystallite size from peak broadening in XRD patterns. Examples of SEM micrographs and XRD patterns are provided to illustrate these techniques.
This document provides an overview of TIG, plasma arc, and MIG welding processes for aluminum. It describes the principles, equipment, parameters, and macrostructure outcomes of each process. The objectives are to explain TIG, plasma arc, and MIG welding and their modifications for aluminum, how welding parameters influence macrostructure, and the choice of parameters. It requires a general engineering background and basic electrical engineering knowledge. The document was created in 1994 and contains 47 figures to illustrate the concepts discussed over 36 pages.
This document provides an overview of liquid penetrant inspection (LPI), a nondestructive testing method used to detect surface-breaking flaws. It discusses how LPI works by drawing colored dye into flaws via capillarity, and the basic six-step LPI process: 1) cleaning, 2) penetrant application, 3) excess penetrant removal, 4) developer application, 5) inspection, and 6) post-cleaning. The document also covers penetrant and developer materials and their properties, factors that influence the process, and advantages and limitations of LPI for nondestructive surface flaw detection.
Fatigue is the progressive and localized structural damage that occurs when a material is subjected to fluctuating stresses that are less than the static yield strength of the material. It accounts for about 90% of industrial failures. Fatigue occurs in five stages: cyclic plastic deformation, crack initiation, crack propagation, propagation of macro cracks, and final fracture. It is characterized by beach marks and a rough, brittle fracture surface. Fatigue life can be represented using an S-N curve which plots the maximum stress versus the number of cycles to failure. The fatigue limit or endurance limit is identified as the stress below which a material can undergo any number of stress cycles without failure.
Lubrication is important to reduce friction between moving parts and prevent damage. Lubricants like oils minimize friction and energy loss from rubbing surfaces. The main functions of lubricating oil are to reduce friction and wear, act as a coolant, reduce noise, provide sealing and cushioning. Good lubricants have properties like high viscosity index, chemical and thermal stability, cleanliness and resistance to extreme pressure. Lubricants can be mineral oils from petroleum, synthetic or animal/vegetable oils, and come as liquids, greases or solids. Lubrication systems include splash, pressure and dry sump to deliver oil under pressure to engine components like bearings and gears.
Thermographic testing uses infrared cameras to detect differences in surface temperatures that may indicate issues. It allows non-contact inspection of electrical equipment, buildings, industrial processes, and more. Key advantages are that it is non-destructive, fast, and can detect problems like loose connections, moisture ingress, insulation issues, and more from a distance. Operator experience is important to properly set up the infrared camera and interpret thermal images.
This document provides an overview of safe handling practices for compressed gases. It defines compressed gases and lists various gas properties like being under high pressure, toxic, corrosive, or flammable. The document outlines identification markings on gas cylinders and regulations for transportation, storage, and use. It describes hazards of compressed gases and emphasizes treating all cylinders with care. The document also reviews functions of pressure regulators, safety devices, and developing an emergency plan for gas releases.
Vacuum is the reduction of air pressure in a container using vacuum pumps. Different types of pumps are used to obtain different levels of vacuum pressure ranging from rough vacuum to ultrahigh vacuum. Rotary pumps are used for rough vacuum between 760 Torr to 10-4 Torr. Diffusion pumps are used for higher vacuums from 100mT to 10-10 mTorr using fluid entrainment. Sputter ion pumps provide ultrahigh vacuum through ionization and trapping of gas atoms without fluids or moving parts. Vacuum is measured using gauges like the Pirani gauge for rough vacuums from 0.5 Torr to 10-3 Torr based on thermal conductivity, and ion gaug
The document summarizes the key components and processes involved in oil production from offshore platforms. It describes how oil and gas are separated after being extracted from subsea wells through manifolds and gathered into the platform. The separated oil, gas, and water then undergo further treatment processes like compression and removal of impurities. Final stages involve storage of oil and gas, metering for export, and transfer through pipelines or marine loading to tankers for transportation.
The document provides guidance on general safety procedures for welding and cutting. It discusses factors like ventilation, protective clothing, equipment, and procedures for oxy-acetylene welding. Specific safety topics covered include ventilation requirements for different space dimensions and welder numbers, appropriate protective clothing like wool, proper use and storage of gas cylinders, checking for leaks, lighting and shutting down torches, preventing backfires and flashbacks, safely welding containers, and cleaning methods for containers that previously held combustible materials. Management is responsible for ensuring welders have proper ventilation and protection.
The document discusses offshore gas production and processing systems. It explains that associated gas from an FPSO can be 1) exported, 2) used for gas lifting/injection, 3) used as fuel gas, or 4) flared during shutdowns. It then describes the multi-stage compression and cooling processes the gas undergoes, including scrubbing, dehydration using glycol or molecular sieves, and cooling to remove condensates before export via pipelines. Hydrates are gas-water compounds that can form and block pipes, but chemical injection or dehydration can prevent their formation.
COMPRESSED AIR SYSTEM . ENERGY CONSERVATION OPPORTUNITIESManohar Tatwawadi
The presentation gives an idea as to how the compressed air system is designed and the performance of the compressed air system. The losses, conservation of energy, the cost of leakages etc are discussed in the presentation
The document describes treatment methods for transformer oil used in power transformers. It discusses how oil undergoes aging over time due to the formation of acids and sludge, reducing its insulating properties. Methods described for treating oil include filtration under vacuum to remove solids, water, and air, centrifugal methods to extract solids and water, and passing oil through adsorption columns filled with materials like fuller earth or silica gel to remove dissolved gases and water. Proper treatment is needed to restore oil purity and dielectric strength.
Ethylene Unit Cracked Gas Compressor Case Studies on Fouling.pdfMeysamAmini4
This manual is designed to familiarize users
with applications for axial flow fans,
velocity recovery stacks, seal discs, and
variable flow fans. Calculations are provided
for estimating fan power consumption and
noise.
- Power transformers are vital components in power transmission and distribution systems that are used to increase or decrease voltage levels. They require protection against faults and overloads to prevent damage.
- Common protection schemes for power transformers include Buchholz relays, differential relays, restricted earth fault relays, overfluxing relays, pressure and temperature monitoring, fire protection, and backup overcurrent and earth fault protection. These schemes aim to quickly detect and isolate internal and external faults to minimize disruption.
- Internal faults can be caused by winding failures, insulation breakdown, or short circuits. Differential relays provide the best protection against internal faults by comparing currents entering and leaving the transformer. Restricted earth fault relays complement this
Oxygen MANUFACTRE STORAGE PREPERATION AND CLINICAL ASPECTDr.RMLIMS lucknow
Oxygen is produced primarily through two main methods - fractional distillation of air and pressure swing absorption. It is stored in large bulk systems or compressed gas cylinders. Cylinders come in various standardized sizes and have safety features like pressure relief valves and color coding. Oxygen is delivered to patients through devices like nasal cannulas, masks, or venturi masks which mix oxygen with air to precisely control the fraction of inspired oxygen. While oxygen therapy is useful for treating hypoxemia, high concentrations over long periods can cause toxicity issues like pulmonary fibrosis or retinopathy of prematurity in newborns.
This presentation summarizes the services of SDMI, a company that specializes in transformer maintenance. SDMI has the world's largest database of transformer test records, processes over 1 billion gallons of transformer oil, and performs over 300,000 oil samples annually. Their services include analytical testing of transformer oil and solid insulation, substation services, engineered products like oil reclamation systems, and PCB disposal. SDMI recommends routine oil testing to monitor aging and contamination, and diagnostic testing like dissolved gas analysis to identify abnormal transformer operation. Regular testing and maintenance can extend transformer life by removing degradation byproducts from the oil and paper insulation.
Talk on energy efficiency by ajai aroraRatan Kuber
The document discusses various ways to improve energy efficiency in textile industries. Thermal energy consumption can be reduced by minimizing water usage during wet processing as water heating accounts for a large portion of energy usage. Process and machine modifications, optimized chemical recipes, and new technologies can help conserve energy. Focus areas for energy savings include reducing steam consumption during wet processing operations like evaporation and chemical heating. Electrical usage can be lowered by improving efficiency of wet processing machinery. Captive power generation and use of waste steam for turbines are also discussed.
The document discusses the organic Rankine cycle (ORC) and its use in low-temperature applications such as solar thermal power plants. Some key advantages of the ORC are its ability to operate at lower temperatures, improving collector efficiency, and its smaller equipment size. Common working fluids for ORC include organic compounds and hydrocarbons like n-pentane. Selection of the working fluid and expander type are important design considerations that influence factors like efficiency, power output, and cost. Positive displacement expanders like scroll expanders are often preferred over turbines due to their ability to handle two-phase fluid and higher pressure ratios. The document provides details on ORC system components, measurement devices, and testing procedures.
Transformer Accessories for Testing and ProtectionSAGAR D
Standard Accessories on an Oil Filled Transformer:
Liquid level gauge
Liquid temperature gauge
Pressure-vacuum gauge
Pressure relief device
Winding temperature gauge
Transformer cooling fans
High voltage bushings
Low voltage bushings
De-energized tap-changer
Buchholz relay
galvanized radiators
Breather
Lifting lugs
Jacking facilities
Multi-ratio, current transformers (CTs) for relaying service
Surge arresters
Grounding devices, such as reactors and resistors
De-energized tap changer (DETC)
Load tap changers
Conservator oil preservation systems
Various monitoring devices for gas, oil and winding temperatures; power factor; moisture; etc.
Most customer-specified accessories
The REX oil mist collector /eliminator design minimizes the reliance on filters, is suitable for high mist applications provides exceptional fluid drainage and air quality exhaust, low maintenance and life-cycle cost.
This document provides an overview of steam heating systems from an energy efficiency perspective. It discusses the components of boilers, including burners, controls, and maintenance. It describes the combustion process for oil and gas firing. It also outlines different types of steam heating piping arrangements like one pipe, two pipe, and systems using condensate pumps or vacuum pumps. Key components like steam traps, controls, sensors and pressuretrols are explained. Maintenance topics like tuning the boiler and combustion testing are covered.
1. Vaporizers are devices that change liquid anesthetic agents into vapor for delivery to patients. They work by allowing gas to flow over or bubble through the liquid agent in a vaporizing chamber.
2. Modern vaporizers are specifically designed for individual agents, have temperature compensation, and feature variable bypass mechanisms to regulate vapor concentration.
3. Placement of vaporizers between the common gas outlet and breathing system on the anesthesia machine is an acceptable location.
The document summarizes a student project on designing a refrigerant recovery unit. It includes an introduction describing the harmful effects of releasing refrigerants into the atmosphere and the goal of recovering and reusing refrigerants. It then describes the major components of the recovery unit, including a compressor, condenser, fan motor and filter drier. Diagrams of the refrigerant recovery process and unit components are provided. Design details such as the use of acrylic sheets and technical specifications of the unit are also summarized.
This document provides an overview and instructions for a temperature and humidity chamber model SDH102P. It describes the chamber's functions, components, operating characteristics, maintenance procedures, and troubleshooting tips. The chamber can control temperature from -100C to +100C and humidity from 30% to 95% RH. It is used to test products under different environmental conditions and assess qualities like heat, cold, dry, and wet resistance. The document outlines the refrigeration system components and cycle, as well as preventative and corrective maintenance steps for the electrical, refrigeration, and other parts. Troubleshooting tips are provided for issues like high/low temperatures, noise, pressures, and refrigerant levels.
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Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
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This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
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Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
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Time Division Multiplexing (TDM) is a method of transmitting multiple signals over a single communication channel by dividing the signal into many segments, each having a very short duration of time. These time slots are then allocated to different data streams, allowing multiple signals to share the same transmission medium efficiently. TDM is widely used in telecommunications and data communication systems.
### How TDM Works
1. **Time Slots Allocation**: The core principle of TDM is to assign distinct time slots to each signal. During each time slot, the respective signal is transmitted, and then the process repeats cyclically. For example, if there are four signals to be transmitted, the TDM cycle will divide time into four slots, each assigned to one signal.
2. **Synchronization**: Synchronization is crucial in TDM systems to ensure that the signals are correctly aligned with their respective time slots. Both the transmitter and receiver must be synchronized to avoid any overlap or loss of data. This synchronization is typically maintained by a clock signal that ensures time slots are accurately aligned.
3. **Frame Structure**: TDM data is organized into frames, where each frame consists of a set of time slots. Each frame is repeated at regular intervals, ensuring continuous transmission of data streams. The frame structure helps in managing the data streams and maintaining the synchronization between the transmitter and receiver.
4. **Multiplexer and Demultiplexer**: At the transmitting end, a multiplexer combines multiple input signals into a single composite signal by assigning each signal to a specific time slot. At the receiving end, a demultiplexer separates the composite signal back into individual signals based on their respective time slots.
### Types of TDM
1. **Synchronous TDM**: In synchronous TDM, time slots are pre-assigned to each signal, regardless of whether the signal has data to transmit or not. This can lead to inefficiencies if some time slots remain empty due to the absence of data.
2. **Asynchronous TDM (or Statistical TDM)**: Asynchronous TDM addresses the inefficiencies of synchronous TDM by allocating time slots dynamically based on the presence of data. Time slots are assigned only when there is data to transmit, which optimizes the use of the communication channel.
### Applications of TDM
- **Telecommunications**: TDM is extensively used in telecommunication systems, such as in T1 and E1 lines, where multiple telephone calls are transmitted over a single line by assigning each call to a specific time slot.
- **Digital Audio and Video Broadcasting**: TDM is used in broadcasting systems to transmit multiple audio or video streams over a single channel, ensuring efficient use of bandwidth.
- **Computer Networks**: TDM is used in network protocols and systems to manage the transmission of data from multiple sources over a single network medium.
### Advantages of TDM
- **Efficient Use of Bandwidth**: TDM all
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3. 3
Why is a Vacuum Needed
• Evacuation increases the mean free path of electrons. The
mean free path of electrons at atmospheric pressure is only
1 cm. At 10-6 Torr they can travel several meters (about 6.5
m) and eliminate electron scattering
• No interaction of electron beam and gas molecules.
Eliminate electrical discharges, particularly between anode
and cathode and in area around field emitters
• It increase Filament’s life. Elimination of oxygen prevents
“burning out” of filament
[1]
4. 4
Why we need Vacuum?
To move a particle in a (straight) line over a large distance
[2]
5. 5
Why we need Vacuum?
Contamination
(usually water)
Clean surface
Atmosphere (High)Vacuum
To provide a clean surface
[2]
11. Rotary Pump Precautions
• Two aspects that are often overlooked are the use of
the ballast valve and replacement of oil at the
correct intervals.
• Ballast valve allows the ingress of air from the
atmosphere into the pump, purging volatiles from
the oil
• While ballasting, vacuum will be limited to ~10-2
mmHg in place of normal 10-3 mmHg
• Normally, ballasting for ~15 minutes each week is
adequate or consult to manufacturers’ manual
11
12. Rotary Pump Precautions
• Always use high quality oil i.e., a low
vapour-pressure oil such as PFPE
(Perfluoropolyether)
• When a RP is switched off, it should be let
up to atmosphere (without letting air into a
hot diffusion pump) otherwise the oil will
be sucked into any lines or chambers
connected.
12
13. Rotary Pump Oil
• Oil exhausted due to vapour saturation/impurities pick up
• Normally it may be used for years
• Fresh oil is clear and color less
• Signs for degradations are:
– Oil level is low
– Oil is a dark-brown /yellow colour
– Oil is turbid due to a build-up of water /vapours
– Pump becomes slow
• If oil looks OK but the pump is slow then ballasting may
improve performance
13
14. Oil Change Precautions
• Treat as hazardous waste (samples/compound used have been
concentrated)
• Use PPE/if possible replace in fume hood.
• Turn off and Isolate pump, allow oil to cool down
• Take out oil and rinse it with fresh oil for 1-2 mins
• Fill fresh oil to 75% of the full mark or as indicated by min-
max lines
• Change oil-mist filter
• Run the pump for 5-10 minutes and check the level and
refill/top-up if needed
• Retain the equipment used for oil drainage; it is impossible to
clean it for any other use.
14
15. gurgling noiseBallasting The
RP
• Pump out normally, then slightly open the ballast-
valve until one hear the low-frequency gurgling
noise.
• This will allow vapours in the oil to easily escape the
pump
• Normally 15mins of ballasting once in a week is
sufficient
• May be done for a day in this condition – but don’t
use machine/EM
15
20. 20
Boil the oil
Condense Oil Vapor (cooling coils)
Condensing vapor sweeps gas
molecules down
Reboiling releases gas molecules
which are then removed by
mechanical pump
Diffusion Pump Cont..
[4]
26. 28
Must be used in conjunction with another (usually rotary) pump
Can’t be used at greater than 10-2 Torr.
Hot oil will deteriorate “crack” and form tar. Diffusion oil is
VERY expensive ($1-2 per ml.)
If cooling system or backing pump fails oil will “backstream” into
the system by way of diffusion
Needs time to heat up and cool down (~30 min)
Diffusion Pump Considerations
Diffusion Pump Cont..
[4]
27. 29
Diffusion Pump
Advantages
Simple design
Relatively cheap
No moving parts
No vibration
Pumps light gasses well
Tolerant of particles
Disadvantages
Oil Vapor Can “crack”
Time to heat up/cool down
Needs coolant
Can overheat
If lose RP, will have oil
throughout system
Diffusion Pump Cont..
[4]
29. Turbomolecular Pump
• Like a jet engine that pulls air instead of pushing
it.
• Turbine spins ~ 20-50,000 rpm creating
“downdraft” which sweeps out gas molecules.
Multiple stages of rotating blades (rotors) spaced
between fixed blades (stators).
• Usually requires rough (backing) pump although
in theory can go from atmosphere
31
Turbomolecular Pump Cont..
[4]
33. 35
Turbomolecular Pump
Advantages
Very high Vacuum
10-7 Torr.
Very clean (no oil)
Relatively fast
Disadvantages
Must be vibration
damped
Sensitive to movement
Moving parts
Very expensive
Turbomolecular Pump Cont..
[4]
34. 36
Ultrahigh
(< 10-7 Torr)
High
(10-3 ~ 10-7 Torr)
Medium
(1 ~ 10-3 Torr)
Low
(760 ~ 1 Torr)
Rotary Rotary
Sorption Sorption
Diffusion Diffusion
Turbomolecular
Turbomolecular
Sputter ion Sputter ion
Cryogenic Cryogenic
The different vacuum pumps
[5]
36. 38
Acetone & Alcohol Precautions
• When heated, sprayed or exposed to high temperature, are become
flammable and explosive, causing serious injury or death.
• Acetone or alcohol are 4 to 5 times heavier than air and flows
down, settling in tanks, pits, and low areas, thus displacing air
creating which can kill by asphyxiation (Deficiency of oxygen).
• Acetone, alcohol, and other solvents are irritants, narcotics,
depressants, and carcinogenic.
• Their inhalation and ingestion may produce serious effects.
• Prolonged or continued contact with the skin will result in
absorption through the skin and moderate toxicity.
[10]
37. 39
Acetone & Alcohol Precautions
• Always ensure that cleaning operations are carried out in
large, well-ventilated rooms.
• The use of a self-contained breathing apparatus may
also be necessary.
• Wear eye shields, gloves, and protective clothing.
• Solvents degrade O-ring materials reducing their ability
to hold vacuum.
• If necessary to clean O-rings, wipe them with a clean,
lint-free cloth or use a small amount of DP-oil.
[10]
39. 41
Measurement of pressure
• Mechanical phenomena gauges: measure
actual force exerted by gas (e.g. manometer).
• Transport phenomena: measuring gaseous
drag on moving body (e.g. spinning rotor
gauge) or thermal conductivity of gas (e.g.
thermocouple gauge).
• Ionization phenomena gauges: ionize gas and
measure total ion current (e.g. ion gauge).
• Partial pressure residual gas analyzers: mass
spectrometers.
[5]
43. 45
• As a gas increases in density (indicate an increase in pressure),
its ability to conduct heat increases.
• A wire filament is heated by running current through it.
• A thermocouple or Resistance Temperature Detector (RTD)
is used to measure temperature of filament.
• This temperature is dependent on the rate at which the filament
loses heat to the surrounding gas, i.e. depend on thermal
conductivity.
• A common variant is the Pirani gauge which uses a single
platinum filament as both the heated element and RTD.
• Working range is 10 Torr to 10−3 Torr, but are sensitive to
chemical composition of gases being measured.
Thermal Conductivity based Gauges
[6]
44. 46
• A Pirani gauge is a one wire gauge
• The wire is heated by a current flowing through it and
cooled by the gas surrounding it.
• If pressure is reduced, the cooling effect will decrease,
hence the equilibrium temperature of the wire will
increase.
• The resistance of the wire is a function of its
temperature: by measuring the voltage across the wire
and the current flowing through it, the resistance (and so
the gas pressure) can be determined.
• Thermocouple gauges and thermistor gauges work in
a similar manner, except a thermocouple or thermistor is
used to measure the temperature of the wire.
Thermal Conductivity based Gauges Cont..
[6]
45. 47
Uses a wire (platinum) in a sealed vacuum tube (reference)
and a second wire in specimen chamber.
Apply a constant voltage of 6-12V to heat the wires.
The resistance of the wire is a function of its temperature,
so current through it (or voltage across it) will have
relation with the gas pressure. The higher the temperature,
the greater the resistance and the less the current flow.
Normal working range 0.5 Torr to 10-4 Torr.
Pirani Gauge
Thermal Conductivity based Gauges Cont..
[4,6]
46. 48
The thermal conductivity of the gas may affect the reading. So for more
precise readings in a particular chamber/environment calibration procedure is
executed.
Thermal Conductivity based Gauges Cont..
[4]
47. 49
• Most ion gauges come in two types:
Hot cathode
Cold cathode
Spinning rotor gauge: more sensitive and expensive but
rarely used
• Most sensitive and used for very high vacuum
10-10 - 10-3 torr
Ionization Gauges
[6]
48. 50
• In Hot-cathode gauge, gas is bombarded with high
energy electrons produced by heated filament (thermionic
emission) giving positive ions.
• The ions are attracted towards a charged electrode called
Collector.
• Collector current is proportional to ionization-rate, i.e.
function of pressure
• The principle of Cold-Cathode gauge is the same,
except that electrons are produced by discharge of a high
voltage.
Ionization Gauges
49. 51
• Its Calibration is very sensitive to:
Construction geometry
Chemical composition of gases
Corrosion and surface deposits
Their calibration can be invalidated by activation at
atmospheric pressure or low vacuum
• The composition of gases is usually unpredictable, needing
MS(Mass Spectrometer) with IG for high accurate
measurement.
Ionization Gauges Cont..
50. 52
• The calibration is unstable and dependent on the
nature of the gases being measured, which is not
always known.
• They can be calibrated against a McLeod gauge
which is much more stable and independent of gas
chemistry.
Calibration of IG
51. 53
Cold Cathode Ionization Gauge
• The major difference between the two is the position of
the anode with respect to the cathode.
• Neither has a filament,
• Both require DC potential of ~ 4 kV for operation.
• Inverted magnetrons can measure down to 10−12 Torr.
• Penning gauge by Frans Michel Penning
• Inverted magnetron or Redhead gauge
Ionization Gauges Cont..
52. 54
Penning Gauge
It is a cold-cathode based.
Get current flow between anode and cathode by applying high
voltage ~4k which ionizes gas molecules
The more gas molecules, the more will be collisions i.e. more
ions or more current in measured
Ionization Gauges Cont..
[4]
53. 55
• There is a lower vacuum limit for IGs, like for Penning gauge is
~ 10−3 Torr
• This is due to shorter mean free path in presence of more gas
molecules, leading to less current by recombining ions before
reaching anode
• Similarly, cold-cathode gauges has problem to start at very high
vacuum (near-absence of a gas molecules), i.e. difficult to
establish an electrode current
• For PG, a symmetric magnetic field is used to create path
lengths for ions
• Additionally, in PG, the electrode is fine-tapered to facilitate the
field-emission of electrons, thus easing the set-up of discharge
path.
Ionization Gauges Cont..
54. 56
• Cold-cathode gauges has less Maintenance-Cycles and works
for years depending on gas type and pressure operated.
• Gases with substantial organic components, such as pump oil,
can result in growth of carbon layers, leading to
• Short-circuit the electrodes of the gauge
• Impede the generation of a discharge path
Ionization Gauges Cont..
[6]
56. 58
Ionization Gauges
(Hot Cathode)
Ionization Gauges Cont..
[2]
• Thermionic/hot cathode ionization gauges.
• Energetic beam of electrons used to ionize gas
molecules and produce ion current.
• Upper pressure limit (10-3 Torr): secondary ion
ionization excitation, filament burn out.
• Lower pressure limit (10-10 Torr): secondary
electron current from X-ray emission.
60. 62
Vacuum Gauges are
Calibrated by
• Attachment to calibrated vacuum system.
• Comparison with calibrated reference
gauge.
• Comparison with absolute standard
calibrated from its own physical properties.
61. 63
Ultrahigh
(< 10-7 Torr)
High
(10-3 ~ 10-7 Torr)
Medium
(1 ~ 10-3 Torr)
Low
(760 ~ 1 Torr)
Manometer Manometer
Thermocouple Thermocouple
Spinning rotor
Ionization
Ionization
Mass
spectrometer
Mass
spectrometer
Spinning rotor
Vacuum gauges used in vacuum
systems
[5]
62. 64
Vacuum Systems in EM
• Different levels of vacuum are
required for different portions of the
microscope
• Gun:10-9 Torr
• Specimen: 10-6 Torr
• Chamber and Camera: 10-5 Torr
Vacuum System Cont..
[4]
63. 65
Pir = Pirani Gauge
V = Valve
ODP = Oil Diffusion Pump
Pen = Penning Gauge
Igp = Ion Getter Pump
PVP = Pressure Variable Pump
(rotary)
Vacuum System Cont..
[4]
64. Getting Better Vacuum
• Use best quality oil for RP/DP
• Prevent back-streaming of oil vapours into the EM,
– Use a bakeable vapour trap in the rough pumping line
– If possible (and it unfortunately may be difficult) fit a
LN trap above DP
• Changing O-rings to ‘Viton’ type will make a
significant improvement
• Viton O-rings do not need greasing and offer
better seals at higher vacuum
• Never grease O-rings until used in moving parts
66
65. Leak Detection
It rarely happen under normal operation, so be
carful for major dismantling
• Remove the specimen; it may be wet and/or
outgassing
• Check the O-ring on the stage, and the
associated sealing surface
• Remember that if you have just cleaned an
internal component then the EM may take
hours to reach a good vacuum
67
66. Detecting Leaks
• Take good sensitive analogue vacuum meter and a high
vacuum gauge head hooked up to an appropriate part of the line
• Freon, Arklone and Helium are common leak sprays that are
harmless but volatile
• Previously Ether (dangerous) was used because this is highly
volatile and it finds its way very quickly through the leak and
vaporizes quickly to give a blip on the vacuum meter.
• Work systematically: Spray on a part and wait for ~30 secs and
then proceed for the next
68
72. 74
• Check the Element / filament. It might be
ruptured or blown out. Should be replaced.
• Check the PCB/preamp section.
• For lower values check the supply voltage.
Gauge shows full range or continuously
lower value:
74. 76
– Cleaning for deposition / contamination
– Supply voltage (usually 24~34 volt) too noisy
• Trace out the noise source, if it is from power supply,
look at their filters.
• Usually a filter capacitor can remove the pickup
noise.
Measuring Signal Unstable
[8]
75. 77
• May be very dirty / Contamination on inside,
– May have got carbon layer due to back-streaming of
pump oil
– May be cleaned with metal polishes.
– Be careful for Trigger-Electrode (present in some
models) not need to be wiped off and bend.
– Give it a soak in acetone, be careful for using more
aggressive caustics or acid base cleaners, unless given for
some specific gauges.
– After washing/cleaning, heat it gently with some heat-gun
or hair dryer till it warms to touch.
Unstable or Erratic Results
Penning Gauge
76. 78
• Fluctuation in the gauge HV circuitry.
– Disconnect the power supply, test the components,
soldering and connections.
– Be careful, the gauge uses several thousand voltages, so
there might be a chance of capacitor charge, so wait for at
least 5minutes when turned off.
• ADC Circuit failure
– Check the conversion circuit for their components,
operating supply and reference voltages for the ADC.
Unstable or Erratic Results
Penning Gauge
78. 80
Changing Heater
Element
• Disconnect the supply
• Remove the polished reflector
cover.
• Remove the block containing the
defective heater.
• Remove the heater from its hole
and replace with a new element.
• Coat the replacement heater with
milk of magnesia before
inserting in the block. This
prevents seizing of the element on
repeated heat up, and make future
servicing easier.
• Reconnect heater and check its
continuity
• Replace the polished reflector.
• Use penetrating oil if necessary.
[9]
79. 81
Precautions for DP
• Do not run pump without cooling water
• Do not run pump with low level of pump Oil
• Do not open drain plug when pump is in vacuum
and especially when heater is hot
• Do not override pressure, thermal switch and
valve sequencer interlocks.
• Do not weld/machine any part without removing
all fluids or solvents. [10]
81. 83
Inlet Pressure Surges
• Incorrect heater voltages
• Fluid out-gassing, condition fluid by operating the
pump for 24 hours.
• Leak in the system inlet.
[10]
82. 84
Poor System Pressure
• Leaks in the system, virtual or real
• Contaminated pump oil
• Low heat/temperature, check input voltage,
heater resistance, poor thermal contact.
• High foreline-pressure
– Check foreline connection
– Poor performance RP, TMP
– Check its oil, oil-breakdown
[10]
83. 85
Cleaning
• Disconnenct power & allow to cool
• Disconnect the inlet-flange and the
foreline connections, be careful for
the O-rings for any scratch or
damage.
• Remove the cold cap and jet
assembly .
• Drain the oil and remove all O-rings
and gaskets.
• Wash the pump interior body and
the jet assembly with acetone.
• Rinse it with isopropyl alcohol
followed by drying with dry
nitrogen.
• Reinstall and fill the pump with oil
up to the level. Jet Assembly [10]
86. 88
Acetone & Alcohol Precautions
• When heated, sprayed or exposed to high temperature, are become
flammable and explosive, causing serious injury or death.
• Acetone or alcohol are 4 to 5 times heavier than air and flows
down, settling in tanks, pits, and low areas, thus displacing air
creating which can kill by asphyxiation (Deficiency of oxygen).
• Acetone, alcohol, and other solvents are irritants, narcotics,
depressants, and carcinogenic.
• Their inhalation and ingestion may produce serious effects.
• Prolonged or continued contact with the skin will result in
absorption through the skin and moderate toxicity.
[10]
87. 89
Acetone & Alcohol Precautions
• Always ensure that cleaning operations are carried out in
large, well-ventilated rooms.
• The use of a self-contained breathing apparatus may
also be necessary.
• Wear eye shields, gloves, and protective clothing.
• Solvents degrade O-ring materials reducing their ability
to hold vacuum.
• If necessary to clean O-rings, wipe them with a clean,
lint-free cloth or use a small amount of DP-oil.
[10]
A substance with a high vapor pressure at normal temperatures is often referred to as volatile.
perfluoropolyether (PFPE), perfluoroalkylether (PFAE) and perfluoropolyalkylether (PFPAE).
Vapor pressure or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system