A key characteristic of singleacting mechanical seals is that they can leak into the surroundings of the vessel. At utex, we refer to this type as rs1 the assembly shown in the pump is configured with a. Keep noise, vibration or flood confined to the mechanical room installs around any pipe or conduit hydrostatically seals the penetration to 20 psi waterproof, no drying or curing time. We believe the best way to service the end user is through our strategic alliances with distribution partners. As seal technology has advanced, the standard has expanded to incorporate. The metraseal effectively seals off the mechanical room from the rest of the system. A mechanical seal can now be defined as a device which prevents fluid leakage where a rotating shaft extends through a pressurized vessel. This role of mechanical seals contributes to the prevention of environmental contamination, energy saving through improved machine operating efficiency, and machine safety. If you are unable to identify the seal, it will be necessary for you to. Mechanical design engineering handbook is a straighttalking and forwardthinking. The bellows high strength and flexibility is the key to the very reliable. Bulletin number twentynine selecting mechanical seals.
Mechanical seals, third edition is a source of practical information on the design and use of mechanical seals. The mechanical seal is a precisionengineered product. Like packing, the mechanical seal faces must also be lubricated. For double mechanical seals backtoback en specifies the short type only. Examines the fundamentals and practice of both the design and operation of face seals, ranging from washing machines to rocket engine turbopumps. A few basic components and principles in mechanical seal design contribute to a working seal at the interface of the rotating shaft and. Carefully position the stationary assembly mating ring of mechanical seal 433. This article will explain what a mechanical seal is and the key design features that make them work. The importance and basic functions of mechanical seals.
A special design of the seal rings gives the possibility to operate both in an. Mechanical seals hvac we provide quality, reliable sealing solutions for cooling towers, hot and cold water circulation pumps, booster pumps, boiler. Mechanical seals according to en 12756 code system for single mechanical seals there is a distinction drawn between standard n and short k types. Request pdf types of seals seals are devices used to prevent or limit leakage of fluids or particulates. Cartridge mechanical seals gaddis mechanical seals. Mechanical seals of conventional design and material can be selected to function at pressures up to 200 atmosphere, at speeds up to 50,000 rpm and with a temperature ranging from 200 deg c to 650 deg c. Probably the most widely recognized and also most common mechanical seal used in general service, low pressure applications. Mechanical seals are designed to overcome these drawbacks. Unbalanced seals figure a are mechanical seals designed so that the full hydraulic. Mechanical seal technology and selection eagleburgmann. The approach of analysis was using seal design equations as mathematical models for simulating the performance of the mechanical seal.
Our extensive range of mechanical seals includes standard cartridge, pusher, metal bellow, mixer, compressor, slurry, gas barrier and containment, oem and. Mechanical seals are intended to prevent the fluid water or oil used by a machine from leaking to the external environment the atmosphere or a body of water. Metal bellows seals are always balanced, by design. Epdm, neoprene, nitrile, chemraz, kalrez, and viton are available. The basic components in a mechanical seals include the following 1. High pressures produce an excessive closing force which affects the stability. These seals can therefore be used to seal shafts rotating in either direction and in vacuum applications. Wherever a rotating shaft moves fluid, mechanical seals play a key role in sealing process fluids in, keeping contaminants out, or both. Proper seal selection is necessary to achieve emission levels, mtbr goals and energy savings previously unimaginable in the days of mechanical packing. Understanding the basis principles of mechanical seals, design variations, and limits is a tool that allows users to ascertain if. Mechanical face seal replacement how to use this catalogue locate the manufacturer of the equipment. With proper application and design however, the leakage is so minute that actual droplets of liquid are not detected.
Principles and design of mechanical face seals wiley. The standard also describes the shaft seal designation and material codes to be used. Application guidelineswas created as a tool to be used by those who purchase or specify mechanical seals, as well as by the end users of rotating equipment in a wide variety of industries. Mechanical seals ekk technologies eagle industry co. Please consult with all seals for your specific application. It has combined the aspects of seal design, testing, standardization, and applications to provide the users and oems alike with a common source of information for mechanical seals. With a lower k value, the safety against thermal overload will increase, but the mechanical seal may also lift off more easily. This is accomplished by the special spring design, which provides an interference fit. A variety of simple and complex models are proposed and evaluated and specific problems such as heat checking, blistering and instability are considered. Flowserve provides sealing solutions as a single resource for the improvement of end user rotating equipment operations. Secondary seals consisting of orings or other suitable gaskets. The compression spring is wound either right or left hand depending on shaft rotation. Mechanical seal leakage in pumps how much, if at all, mechanical seals do, must or must not leak is a controversial subject for which there are few clear answers. Pdf analysis of mechanical seals for highspeed centrifugal gas.
Typically mechanical seals are installed on pumps and mixers. Keep noise, vibration or flood confined to the mechanical room installs around any pipe or conduit hydrostatically seals. Esp has developed inhouse engineering that helps design oem components such as seals, metal castings and forgings, and also. Balanced mechanical seals are more preferred than unbalanced mechanical seals. Unlike an oring seal, the hydraulic diameter of a bellows seal is not a fixed geometric value. European standard en 12756 dimensions according to en 12756 european standard en 12756 defines the principal dimensions for the installation of single and multiple mechanical shaft seals into pump housings. Typical applications are centrifugal pumps, compressors, turbines, mixers, marine propeller shafts, and aircraft engines. The thin crosssection allows the liberator i to be used in ansi pumps without modifications.
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 portion and the pump housing. The seals are arranged by shaft size from smallest to largest. Failure modes of mechanical seals are analyzed by using the digraph modeling and matrix. A mechanical seal is simply a method of containing fluid within a vessel typically pumps, mixers, etc. After working with customers on design, esp then uses its qualified domestic and global factories to find the. Quality mechanical seals mechanical seals can be found in centrifugal pumps pool and spa pumps. Generally unbalanced seals have good performance when subjected to vibrations, misalignments or cavitation. Mechanical seals touch nearly every aspect of industrialized society. Consider essential elements, the fluid in the seal, leakage, power consumption, lubrication regimes and balance.
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 sealchamber housing. Carefully position the stationary assembly mating ring of mechanical seal. Topics range from design fundamentals and test rigs to leakage, wear, friction and power, reliability, and special designs. Although there are many variations, containment mechanical seals are designed to operate without the presence of a lubricating liquid.
Ksb mechanical seals ksbs range of tailored spare parts services plays a major role in the service portfolio. Design a mechanical seal figure 1, consists of a stationary member. For flowserve, he has served in design, testing, and application functions in both the u. 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. Although massproduced mechanical seals, such as those used in automotive water pumps and household appliances, cost in the. Instead, the lubricating liquid will vaporize as it crosses the. Mechanical seals were originally designed to lend a greater sealing capability than. Seal type the mechanical seal shown in the pump photograph is a type 1 mechanical seal. It employs a multicrested wave spring which is a nonclogging spring isolated from the product for optimum corrosion resistance.
Pdf principles and design of mechanical face seals. Flowserve has been trusted for more than 80 years to design, manufacture and distribute mechanical seals, sealing systems and parts to customers worldwide. An essential mechanical seal contains three sealing points. The cartridgestyle mechanical seal is simply bolted to the seal chamber. In cooperation with our alliance customers, we have improved operational efficiencies to worldclass standards. Instead, the lubricating liquid will vaporize as it crosses the seal faces and the leakage is a gas or vapor. See pages 106110 for the material recommendation chart.
Our collection of mechanical seals is supported by strong aftermarket services, and provides users with safety and environmental benefits. Mechanical seals used as dry running containment seals may be similar in appearance to conventional face type seals, but they include special features and materials. Mechanical seals elastomer bellows sealing operation flowserve elastomeric bellows seals are of compact design with a sealing action that provides many benefits. Therefore, this seal design is suitable for sealing non critical substances and for. This means the vessel is not technically tight, in contrast to double and tripleacting mechanical seals. The manufacturer listings are alphabetical, refer to pages 7. Impressing with a robust design, they offer servicefriendly installation and optimal integration in the seal chamber. The main limitation in the application of unbalanced mechanical seals is the operating pressure. Klozure is a global company with installations worldwide, solving demanding applications big and small. There are many types of mechanical seal, ranging from simple single spring designs to considerably more complex cartridge seal types. Single spring and elastomer bellows mechanical seals. 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. About esp esp offers a suite of products and services that are critical to global oems. Application information before design and material selections can be made at.
Symbols a area of sliding face a h area hydraulically loaded by medium pressure b width of sliding face. Esp has developed inhouse engineering that helps design oem components such as seals, metal castings and forgings, and also provides valueadded assembly, inventory management programs and supply chain logistics. Understanding the basic principles of mechanical seals, design variations, and limits is a tool that allows users to ascertain if they can achieve the mean time between repairs desired. Choose the correct combination of elastomer, metallurgy and sealing faces for your application. The complete product portfolio of systems and components for cooling, flushing, pressurization and supplying liquid and gaslubricated mechanical seals e.
It has combined the aspects of seal design, testing, standardization, and applications to provide the users and oems alike with a common source of. A special design of the seal rings gives the possibility to operate both in an unpressurised system and in a pressurised system as with the backtoback. Mechanical seals technical manual brenner industrial sales. Therefore, this seal design is suitable for sealing non critical substances and for low pressure applications. Even the simplest mechanical seal is a precision piece of engineering requiring high levels of manufacturing accuracy and face flatness. Slide seal cover 471 onto shaft 210 until it rests against bearing bracket 330. Advancements in mechanical sealing api 682 fourth edition abstract api 682 iso 21049 is the leading document for mechanical seals in petrochemical, chemical, and pipeline services worldwide. Capabilities shown in this brochure are directly related to design tolerances. Topics include materials, tribology, heat transfer and solid mechanics. Using a ball drive, the liberator resists twisting and torsional strains common to pin or key drives. A mechanical seal, figure 1, consists of a stationary member seat.
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