Mechanical seal failure logic diagraph msfld is prepared for failure modes of mechanical seals and is described by contributing cause events direct and indirect and their interrelations. Azibert was granted over thirty patents on mechanical seal designs and improvements. Topics range from design fundamentals and test rigs to leakage, wear, friction and power, reliability, and special designs. Doe fundamentals handbook mechanical science volume 1 of 2 u. Centrifugal and rotary positive displacement pumps require controlling of the pumped fluids desire to exit through the stuffing box, the area where the pump shaft enters the pump fluid end. Were finding better ways to serve our customers all the time. At utex, we refer to this type as rs1 the assembly shown in the pump is configured with a.
This course explains the basic need for mechanical seal systems and the theory behind how they work. This is commonly seen in centrifugal pumps although this challenge also exists in other equipment such as agitators, turbines, compressors, centrifuges, and blowers. While its performance is obviously dependent on the design of the seal itself, the ultimate seal performance is influenced by the design and operation of the pump. This presentation discusses those fundamentals as they apply to seals. Mechanical seal fundamentals describes the basics of mechanical seal systems and the theory behind how they work, with emphasis on operation, effects of operating environment and support systems track wo entrylevel vibration trainingiso category 1 certification elvt. Fundamentals provides a detailed explanation of how a centrifugal pump is constructed and operated to achieve maximum reliability track two mechanical seal fundamentals describes the basics of mechanical seal systems and the theory behind how they work, with emphasis on operation, effects of operating environment and support systems track wo. Unlike an oring seal, the hydraulic diameter of a bellows seal is not a fixed geometric value. Mechanical seal fundamentals webinar session 2 siewert. Soildwork mechanical fundamentals of robotic mechanical systems. Fundamentals of mechanical end face seals an end face mechanical seal is a device intended to prevent or minimize leakage from a vessel through the clearance around a rotating shaft entering that vessel. The fundamentals 1 alpha alpha the mechanical seal mechanical seals have the purpose of preventing leakage of a fluid liquid or gaseous through the clearance between a shaft and the fluid container.
As part of their educational mission they develop publications such as the mechanical seal handbook, a primer intended to complement the more detailed manufacturers documents produced by the member companies. Service rotary stationary elastomer metal parts crane type 10k10 standard duty ceramic buna 316 ss 6 10k6 fluct. Seal type the mechanical seal shown in the pump photograph is a type 1 mechanical seal. Mechanical seals are leakage control devices, which are found on rotating equipment. Even though these components are tightly pressed together, a small amount of leakage occurs through a clearance that is related to the surface roughness. This is very important in hazardous applications, even if buffer gas is used on the seals. Mechanical seals are usually endface seals or rotatingface seals, but in some designs they can be circumferential or even a hybrid of liptype seals.
The course is comprised of approximately 50% classroom and 50% laboratory time. The fluid in the pump and seal area and a few facts about the leakage and wear behavior of contacting mechanical seals. The above picture is just a screen shot, click for animated demo. Perhaps the most common example is the end face mechanical seal used in the water pump of an automobile engine. Piping plan fundamentals seal manufacturers and end users alike recognize that a mechanical seal does not operate as a single component. These seals virtually eliminate leakage of the fluid or gas being handled in pumps or mixers. Mechanical seal fundamentals an endface mechanical seal consists of rotating and stationary components which are tightly pressed together using both mechanical and hydraulic forces.
These seals proved to be very effective until shaft speeds, temperatures and other parameters increased with the development of better transportation systems. Mechanical seals first in a series by ann attenasio. Theory, methods, and algorithms mechanical engineering mechanical toy rrb je mechanical mechanical mechanical pat mechanical science pdf mechanical estimating mechanical. Fundamentals workbook contains the independent study course lessons, exercises and final exam materials which must be successfully completed to earn the state assign course credit. A basic mechanical seal contains three sealing points.
Extensive coverage of seal designs, arrangements, etc. Temp up to 212 f carbon niresist 188 ss 10k18 hot water up to 250 f sil. This facilitates the exchange of shaft seal information between shaft seal suppliers and users. Mechanical seals are typically used in applications for superior sealings. This threehour online course is an introduction to one of the most important aspects of mechanical seals fundamentals tailored for all students, beginners, engineers, contractors and professionals interested in piping and pumping systems.
Animated cutsections give a deep insight into mechanical seal operation and how mechanical seals work. Many of the liquids handled by pumps in modern refining, petrochemical, and chemical. A dynamically sealing expeller repels fluid from the seal chamber, making it ideal for hardto seal applications. The seals are preassembled at the factory, pressure tested and shipped as a unit, leading to improved performance as errors due to incorrect installation are reduced. Years ago, most pump shafts were sealed using rings of soft packing, compressed by a packing gland, but this type of shaft seal required a fair amount of leakage just to lubricate the packing and keep. This section covers the fundamentals of mechanical seals, seal types and support systems, seal application and selection, and troubleshooting. In the late 1920s, a self contained shaft seal was created from oil resistant leather assembled into a metal case. Mechanical seals, third edition is a source of practical information on the design and use of mechanical seals. The fundamentals of fluid sealing, including seal operating regimes, are discussed. Jun 10, 2017 ningbo grandbroad mechanical seals mfg. The mechanical seal training program has dedicated modules to assist seal troubleshooting and seal selection api 682 guided seal selection procedure. Instead, the lubricating liquid will vaporize as it crosses the seal faces. Additional topics include materials of construction, fluid properties that affect seal selection, seal. Essential requirements for proper operation of a mechanical seal.
Mechanical seals are simply another means of controlling leakage of a process where other. Cartridge mechanical seal construction is a proven reliability improvement. A few basic components and principles in mechanical seal design contribute to a working seal at the interface of the rotating shaft and stationary pumpmixer seal chamber housing. Water, oil, and chemical mediums with weak corrosion. What is a double seal and when to use one double seals. The general fluidflow equations for fluid sealing are developed. A mechanical seal is a shaft sealing device, which forms a running and dynamic seal between the rotating and stationary parts of a rotary equipment, developed to overcome the disadvantages of the traditional compression gland packing. The seals of the industrial age were organic ropes or packings. Mechanical seal fundamentals mechanical seal fundamentals 20706 10. Doe fundamentals mechanical science module 5 miscellaneous mechanical components. Fundamentals of mechanical seals fundamentals of mechanical end face seals an end face mechanical seal is a device intended to prevent or minimize leakage from a vessel through the clearance around a rotating shaft entering that vessel. The most significantdevelopment in the evolution of the radial lip seal happened toward the end of world war ii. Seal chamber and stuffing box seal chamber and stuffing box both refer to a chamber, either integral with or separate from the pump case housing that forms the region between the shaft and casing where sealing media are installed.
Consider essential elements, the fluid in the seal, leakage, power consumption, lubrication regimes and balance. Despite these advances, however, seal performance remains a hitormiss proposition. Mechanical seals have the purpose of preventing leakage of a fluid. Wherever a rotating shaft moves fluid, mechanical seals play a key role in sealing process fluids in. Optional leakage management systems for arrangement 1 seals are plans 62 and 65. Maintenancefree antifriction bearings with continuous lubrication accessories. This portable document format \ pdf \ file contains bookmarks, thumbnails, and hyperlinks to help you navigate through the document. The impeller 8 is mounted on the pump shaft 5 with roller bearings 7 in either overhung or center hung arrangement. Summary of basic operating principles of liquid lubricated mechanical seals. Typically, a sintered silicon carbide is the matrix so the material has superior oxidation resistance even though it con. Like packing, the mechanical seal faces must also be lubricated. Seals can fail for numerous reasons, including poor lubrication. Type designation the type designation according to en 12756 is based on this coding system for single shaft seals.
Our collection of mechanical seals is supported by strong aftermarket services, and provides users with safety and environmental benefits. Mechanical seals are designed to handle a range of motions and conditions, but they are just one machinery component in a larger system. Mechanical seal fundamentals msf pump training, pump. Vulcan type 24, burgmann mg912, john crane type 521, roten type 52 12 14 16 18. A mechanical seal is a device used to seal the interface between a rotating shaft and a stationary housing figure 1. The stationary part of the seal is fitted to the pump housing with a static seal this may be sealed with an oring or gasket clamped between the stationary part and the pump housing.
Probably the most widely recognized and also most common mechanical seal used in general service, low pressure applications. Mechanical seal technology and selection eagleburgmann. Theory, methods, and algorithms mechanical engineering fundamentals of robotic mechanical systems. Fundamentals of mechanical seal opration the liquid to be pumped enters the suction inlet at the eye of the impeller. Since the seal face is the only sacrificial part of a mechanical seal, a worn out seal has no elastomer nose piece left at the time it started to leak. The seal between the rotating 3 and stationary faces 1. The mechanical seal itself is the interface between the static and rotary portions of the seal. Congress committed to defend the fundamentals of constitution. Itt goulds pumps commercial water mechanical seal item 383 part no.
The mechanical seal division of the fsa is one of six divisions with a specific product technology focus. When the sealing is achieved by means of a mechanical seal, the chamber is commonly referred to as a seal chamber. To install a seal, the pump would have to be taken offline and disassembled. Mechanical science miscellaneous mechanical components ms05i table of contents. This course covers many seal types and related information in the industry.
Mar 18, 2015 fundamentals of mechanical seal opration the liquid to be pumped enters the suction inlet at the eye of the impeller. This was the firstradial lip seal to be press fitinto an outside diameter od bore. Positive shutoff is maintained by the springs as well as a set of figure 3. Mechanical seal fundamentals describes the basics of mechanical seal systems and the theory behind how. Mechanical seal presentation 1 linkedin slideshare. A mechanical seal is simply a method of containing fluid within a vessel typically pumps, mixers, etc. Arrangement 1 seals are usually fitted with either a fixed or floating bushing as the containment device. The liquid centrifugally forced to the out side diameter of the impeller where it. A failed seal still has substantial elastomer remaining at the time it started to leak.
Download the 20092014 world outlook for axial mechanical face seals pdf online. Fundamentals of chiller plant design daikin applied. Furthermore, the need for external flushing and process contamination control are eliminated. Mechanical seals fundamentals a pdh online course for. Heres an example where a paper mill replaced packing with a mechanical seal to stop leakage. However, it can be a very costly venture over time as they require more maintenance, and also allow more product loss than mechanical seals. Concepts and theories are taught in a classroom setting and then reinforced with handson exercises. It has been the foundation for every wilfley pump design, dating back to the groundbreaking model a slurry pump in 1919. The impeller discharges radially into the volute or diffuser 11, which is built into the pump casing. Actually, in some cases, deformations must be no more than microvalues. The standard also describes the shaft seal designation and material codes to be used.
Course description for fundamentals of mechanical seals. The seal between the stationary member 1 and stuffing box face, i. Sealing systems for pumps sealing systems for pumps. The primary sealing surfaces are the heart of the device. Mechanical seal basics and seal selection process training this cbt, with skills tests, makes a great animated study guide for mechanical seal training software. Emphasis is placed not only on the operation of mechanical seals, but also on the environment where they operate pump or other equipment and the support systems that help them survive.
Industrial mechanical seal basics seal selection process. Fundamentals of mechanical seals linkedin slideshare. Flowserve has been trusted for more than 80 years to design, manufacture and distribute mechanical seals, sealing systems and parts to customers worldwide. Participants will use static displays and operational pumps to perform pump and seal settings. This course provides the basic absolutemust knowledge about the fundamentals of mechanical seals that operators and maintenance staff will find useful. Understanding the basics of mechanical seals and how they may be adapted for different application requirements is critical for choosing the best seal for the job and ensuring optimal system reliability. Seals and sealing handbook, 6th edition provides comprehensive coverage of sealing technology, bringing together information on all aspects of this area to enable you to make the right sealing choice.
The seal ring which rotates with the shaft is called the rotary ring. Pem 3 knowledge sharing presentation fundamentals of mechanical seal presented by emmanuel raphael essen mnimeche, mnim, ismn october, 2014 23082015 pem 3 knowledge sharing presentation, october 2014 1 2. This includes detailed coverage on the seals applicable to static, rotary and reciprocating applications, the best materials to use in your sealing systems, and the legislature and regulations. Vessel shaft mechanical seal for arresting leakage liquid agitator blade 23.
The liquid centrifugally forced to the out side diameter of the impeller where it flows out through the discharge nozzle. This is essential when pumping or mixing a dangerous or toxic substance. Included in the discussion are the effects of geometry, surface deformations, rotation, and both laminar and turbulent flows. An end face mechanical seal, also referred to as a mechanical face seal but usually simply as a mechanical seal, is a type of seal utilised in rotating equipment, such as pumps and compressors.
Although the fundamentals of operation of mechanical face seals have only been seriously addressed in the last two decades, important advances in the understanding of seal operation have been made during that time. In end or rotatingface mechanical seal designs, the initial closing force is provided by a spring component, which can be a single coil spring, multiple coil back to basics. The initial closing force ensures that the seal will function properly from startup. Mechanical seals and gasket supply is our specialty. This article will explain what a mechanical seal is and the key design features that make them work. Mechanical sealmixer application data sheet customer contact info.
As the impeller rotates, the centrifugal force causes the seal liquid to collect at the outer edge of the oblong cavity. Packing although mechanical seals had been around for many decades, by 1955 industry had converted only a small percentage of pumps from packing to mechanical seals. When operating the pumped fluid within the stuffing box sees a pressure higher than the. With a lower k value, the safety against thermal overload will increase, but the mechanical seal may also lift off more easily. A mechanical seal consists of 2 principle components. The biggest benefit of using mechanical seals is the drastic reduction in leakage. Cartridge construction eliminates the need to measure and set spring compression, and having a. The process leakage from the inner seal mixes with the buffer liquid and is separated and safely removed within the buffer liquid circuit or the barrier liquid or gas lubricates the seal faces and prevents process liquid leakage.
One part of the seal, either to static or rotary portion, is always resiliently mounted and spring loaded to accommodate any small shaft deflections, shaft movement due to bearing tolerances and outofperpendicular alignment due to manufacturing tolerances. Safety when working with bearings introductory reasons for bearings types of bearings fitting bearings bearing seals and shields how to measure a bearing bearing lubrication bearing lubricants bearing analysis conclusions. Sep 17, 2014 because mechanical shaft seal failures are the number one cause of pump downtime, we decided to dedicate this column to mechanical seal basics. Instead, the lubricating liquid will vaporize as it crosses the seal faces and the leakage is a gas or vapor. The fundamentals of fluid flow are important to understanding the various sealing devices. However, another popular composite is graphiteloaded silicon carbide. Secondary seal nbrepdmviton spring and punched parts steel working conditions mediums. Mechanical seal fundamentals authors session i john merrill. When a pump operates, the liquid could leak out of the pump between the rotating shaft and the stationary pump casing. With proper application and design however, the leakage is so minute that actual droplets of liquid are not detected. Double seals provide a level of safetyzero emissions compliance not possible with single seals.
1172 874 1139 344 1533 1004 193 320 21 1499 87 1311 198 873 246 1043 455 279 3 1545 1315 657 1485 317 1402 1021 1192 408 562 981 1262 537 1054