Standard mechanical seals are usually component seals. Even when leakage isnt visible, harmful vapors could be escaping. The shaft seal is a sealing element which seals the rotating shaft of a centrifugal pump where it passes through the nonrotating pump casing, reducing fluidleakage to atmosphere or the entry of air from outside to a certain level, and keeps wear of the sealing faces as low as possible pumps are specially designed and manufactured to cater for a whole range of different applications. Understanding mechanical seals a free powerpoint ppt presentation displayed as a flash slide show on id. This article will explain what a mechanical seal is and the key design features that make them work. Techmachine design 16481d1509 gudlavalleru engineering college sheshadri rao knowledge village, gudlavalleru, pin. Things like a safer work environment without a wet floor. Types of mechanical keys design of keys, keyways introduction to mechanical key.
A mechanical seal is a type of seal that uses mechanical pressure to seal a certain area or equipment. These seals are generally used in sewage applications and waste water pumps. Jun 30, 20 double seals, or clear liquid flushing from an external source, allow the use of mechanical seals on these difficult liquids. The mechanical seals that have been used in bioprocessing in the past are increasingly seen as dirty designs. Single seals made up of two flat surfaces that slide against each other and are pressed together by a spring. Because of the different sealing modes, there is a difference in the amount of friction caused by the sealing device. Incorrect installation and adjustment are the causes for failure. Please contact us for pricing and further information, including technical datasheets.
A mechanical seal, and more specifically a double mechanical seal, should always be used when the pumped fluid presents a safety, health, or environmental hazard. Heres an example where a paper mill replaced packing with a mechanical seal to stop leakage. Anything from two to ten times more horsepower is consumed by packing compared to mechanical seals. They are often thought of as cleanoutofplace cop seals. For double mechanical seals backtoback en specifies the short type only. This style seal has been engineered to be inexpensive to manufacture and to be durable in service. Types of mechanical sealtypes of mechanical seal mechanical seals are classified by two methods 1. As mechanical seals can be used to seal a myriad of different. Mechanical seals first in a series by ann attenasio. Available with a wide range of seal faces including.
Different types of mechanical seal pump heat transfer scribd. This articles describes some of the commonly used mechanical seal types like cartridge type mechanical seals, balanced type, unbalanced type, conventional, pusher, and nonpusher type of mechanical seals. Mechanical seal presentation 1 linkedin slideshare. Mechanical seal types rotary shaft seals uk seals ltd. In either case, the following components are common to all mechanical seals.
This video is about different types of mechanical seal based on its design. There are various types and arrangement of the mechanical seals being used for the centrifugal pumps. 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. Single spring mechanical pump shaft seals are the most common type of pump seal. The biggest benefit of using mechanical seals is the drastic reduction in leakage. The cop seal is removed, cleaned, and sterilized between batches. This introductory course is particularly suited to those new working with such systems as it provides a basic overview of the different seal types.
For best results with double or tandem seals handling abrasive, the inboard seal faces should be a hard material, such as silicon carbide vs. The effectiveness of a seal is dependent on adhesion in the case of sealants and compression in the case of gaskets a stationary seal may also be referred to as packing. Recirculation from pump seal chamber through a flow control orifice and back to the seal. Dynamic seals used for sealing fluid between parts that move in relation with each other application centrifugal pump gland, valve gland, bearing housing turbinecompressor inter stage and end sealing reciprocating compressors cylinder sealing types q gland packings q mechanical contact seals q labyrinth seal q oil seal q oil film seals.
Between the two faces of the mechanical seal the secondary seals, known as shaft and insert mountings, like orings, wedges and vrings are inserted. A mechanical seal is a device that helps join systems or mechanisms together by preventing leakage e. The rotating face is connected to the rotating shaft while the fixed face is connected to the pump housing. One component is stationary and the other rotates against it to achieve a seal figure 2. 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. There are many different designs of a mechanical seal to meet specific applications. The initial closing force ensures that the seal will function properly from startup. Mechanical seals are simply another means of controlling leakage of a process where other means are deemed to be less capable of performing the task adequately. Mechanical seal technology and selection eagleburgmann. It was the first designed and became a stapel for industrial pumps. For more information you can contact us at 00862158355541,58353145,58353343. Mechanical seals are designed to handle a range of motions and conditions, but they are just one machinery component in a larger system. Mechanical seals according to en 12756 code system for single mechanical seals there is a distinction drawn between standard n and short k types.
This seal design was amount the first single spring seals and proceeded the slightly less expensive type 21 seals. Mechanical seals are used in industrial pumps, compressors, and other applications where a spinning shaft protruding into a wetted process is likely to have continuous, rigorous duty. A key is the piece inserted in an axial direction between a shaft and hub of the mounted machine element such as pulley or gear etc. Double seals, or clear liquid flushing from an external source, allow the use of mechanical seals on these difficult liquids. Mechanical seal powerpoint ppt presentations powershow. Mechanical seals throttle pressure which shorter radial distance. Mechanical seals move the point of the seal away from the shaft to specially designed sealing faces. 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. A mechanical seal is simply a method of containing fluid within a vessel typically pumps, mixers, etc.
Symbols a area of sliding face a h area hydraulically loaded by medium pressure b width of sliding face. Here you know more about manufacturer balanced and unbalanced mechanical seals. Our challenge is to design seals that are able to withstand a wide range of media, different aggregate states and varying pressure and temperature and to. The chapter describes mechanical shaft seals used in grundfos pumps as examples of the variety of shaft seal solutions for different applications. Since mechanical seals are subject to stuffing box pressure, this pressure is utilized to achieve and maintain seal face closure in a nonbalanced seal. External source providing a flowthrough quench to atmospheric side. Mechanical seal machined mechanical seal at shanghai trisun mechanical parts manufacture co. The mechanical pressure with which the plug is forced into an opening causes complete sealing. Presentation on the fundamental of mechanical seal. This elearning course is aimed at individuals who work on systems containing gaskets, mechanical seals and packing. Used where the seal chamber pressure is at discharge pressure mainly vertical pumps. Part 2 types of mechanical seal based on design balanced.
With several types of mechanical shaft seals, the john crane company adopted the tagline, the right. 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. Mechanical seals are used in industrial pumps, compressors, and other applications to provide a leakproof seal between component parts. To install a seal, the pump would have to be taken offline and disassembled. Every system will only work as well as its individual. Mechanical seals move the point of the seal away from the shaft to specially designed sealing faces that gradually wear down. Mechanical shaft seal types and sealing systems grundfos. A mechanical seal consists of 2 principle components. The rotating and the fixed faces are the two vital parts of the mechanical seals. Instead the torque is driven along the rubber bellow which fits on the shaft. All mechanical seal types are available in a range of sizes and materials. Mechanical seal types uk seals has a very extensive range of mechanical seal types.
With several types of mechanical shaft seals, the john crane company adopted the. A plug is jammed into an opening to keep any liquids or gases from entering. There are many types of mechanical seal, ranging from simple single spring designs to considerably more complex cartridge seal types. Since mechanical seals are subject to stuffing box pressure, this pressure ppt presentation summary. Nov 25, 2016 this video is about different types of mechanical seal based on its design. Read the many types of mechanical seals for the unbalanced seals and balanced seals. Ppt understanding mechanical seals powerpoint presentation free to download id. The most significant modifications to the original design of single spring seal are the seal faces.
You do not need prior knowledge or experience to complete this course and it is. There are various types of mechanical seals for each application and operating condition of the equipment but in principle, mechanical seal is a face type seal. A technical seminar on types of mechanical seals presented by n. That reduction in leakage also has an effect on a number of other things as well. 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. Shaft seal at best price by american seal and packing. For the purposes of this discussion, consider that a mechanical seal will outperform common types of packing. It covers about balanced and unbalanced seal, pusher and nonpusher type of seal.