All the above gives rise to extremely demanding requirements for the mechanical seals and for the auxiliary elements supplied with them. Mechanical seals can save maintenance people an immense amount of time and money, but only if theyre installed correctly and properly cared for. 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. Seal mechanical seals, there is no more expensive shaft or sleeve replacements. The washer is held in close contact with seat by spring pressure and the pressure exerted by the sealed fluid. These type of mechanical seals are preassembled cartridges which can be directly installed on. Types of mechanical seals and their characteristics are given below for your ease to choose the rightone for you. Techmachine design 16481d1509 gudlavalleru engineering college sheshadri rao knowledge village, gudlavalleru, pin. Due to the narrow seal face, the seal performs well in high viscosity and antifreeze liquids. The rotating face is connected to the rotating shaft while the fixed face is connected to the pump housing. The materials of seal construction, particularly the sealing faces and elastomers.
This article will explain what a mechanical seal is and the key design features that make them work. You must consider the environment the seal will be exposed to. All mechanical seal types are available in a range of sizes and materials. Mechanical seals according to en 12756 code system for single mechanical seals there is a distinction drawn between standard n and short k types. Cartridgepusher seal basically is installed with moving secondary seal. Read on for a basic understanding of mechanical seals, and how they differ from packing. Mechanical seal types industry standard or custom design.
By replacing your old packing with new stateoftheart u. Must be finished in the same manner as the rotary face. The seal is designed exclusively for sealing rotating shafts. There are multiple designs available for mechanical seal configurations. 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. In this pdf, you can learn or know the different types of mechanical seal manufacture by globe star engineers india pvt. 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. To install a seal, the pump would have to be taken offline and disassembled. The old adage pay me now or pay me later applies to seals. The bta2 features all carbon or high quality resin impregnated carbon, aluminium oxide 96 %, is stationary and the rubber bellows are glued on collar. Mechanical seals are usually endface seals or rotatingface seals, but in some designs they can be circumferential or even a hybrid of lip type seals. It covers about balanced and unbalanced seal, pusher and nonpusher type of seal.
The head is statically sealed to and rotates with a pump shaft. Secondary seal nbrepdmviton spring and punched parts steel working conditions mediums. Different types of mechanical seal free download as pdf file. A mechanical seal can now be defined as a device which prevents fluid leakage where a rotating shaft extends through a pressurized. Increase seal chamber pressure and fluid vapor margin. We produce and supply an expansive cluster of mechanical seal for our esteemed customers which are favored through huge number of clients because of its high caliber and topnotch abilities. There are many types of mechanical seal, ranging from simple single spring designs to considerably more complex cartridge seal types. 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. In plan 11, product is routed from the pump discharge to the seal chamber to provide cooling for the seal and to vent air or. Seal types a cartridge type mechanical seal is a preassembled package of seal components making installation much easier with fewer points for potential installation errors to occur.
The article also describes how the selection of the mechanical seals can be done. Mechanical seal types there are a number of mechanical seal types, each providing advantages for specific applications. Take particular care to avoid damage to lapped sealing faces and flexible sealing rings. Different types of mechanical seal pump heat transfer. The seals of the series are rotate to bellows tightness on shaft. Cartridge construction eliminates the need to measure and set spring compression, and having a. Shelby scottshelby scott western region john crane incjohn crane, inc.
Water, oil, and chemical mediums with weak corrosion. However, because of the delicate components used for this new sealing method, mechanical seal failures are the greatest cause of pump down time. This begs for a better understanding of this seal type and its application. The rotating and the fixed faces are the two vital parts of the mechanical seals.
Seals have more flexibility than packing and are able to compensate for shaft deflection, axial and radial end play, as well as vibration and wear. Between the two faces of the mechanical seal the secondary seals, known as shaft and insert mountings, like orings, wedges and v. John crane carbon mechanical seal prices are pretax. Presentation on mechanical seals sealwell india was estd. Sealwell seals are designed to withstand stringent industrial application in any type of industry, let it be chemical. Type g rubber bellows seal with reduced seal face rubber bellows seal like type b but with a narrow seal face. Design by way of example, a simple mechanical seal design. Mechanical face seal is also known as heavy duty seal, face seal, lifetime. Symbols a area of sliding face a h area hydraulically loaded by medium pressure b width of sliding face. Mechanical seals incorporate a seat stationary ring and washer rotating ring that prevents leakage of the sealed fluid by rotating relative to the seal face. Secondary seals consisting of orings or other suitable gaskets. Mechanical seals type 11 general seal general seal. Understanding how they work will help the professionals to select the appropriate type and their correct application. 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.
Mechanical seal types uk seals has a very extensive range of mechanical seal types. The term seal is used to refer to a variety of products including notary seals i. The seat is statically sealed to a nonmoving cover. Sarbs pump maintenance seminar, june 7, 2012 seal typesseal types causes of seal failure piping plans sealinggg water usage safeunit flowmeters. The ability of a mechanical seal to meet its performance objectives depends upon a wide range of factors involving equipment design, operating conditions, and support systems. The seal ring which rotates with the shaft is called the rotary ring. A technical seminar on types of mechanical seals presented by n. Plan 03 plan 65b plan 66a plan 66b what seal flush from pump discharge through orifice. Mechanical seal technology and selection eagleburgmann. The design, arrangement and materials of construction are essentially determined by the pressure, temperature, speed of rotation and product being sealed the product media. Cartridge mechanical seal construction is a proven reliability improvement. Spread throughout the world, this type of mechanical seal has reached an unsurpassed quality level. Included in this list is the selection of the materials of construction of the seal. The assembly is preset so that no installed length calculations must be performed for determining where to set the seal.
Do not exces sively compress the seal before or during installation. Mechanical seals allow a minuscule almost drop by drop leakage past the seal face to lubricate it to slow seal wear. Plan 11 is the default seal flush plan for all single seals. Special materials can be offered to meet customer requirements. Design by way of example, a simple mechanical seal design has 7 components figure 3. Rubber bellow seal part of identification rotary face dynamic ring stationary face stationary ring elastomer bellow spring other hardware. Mechanical seal seals are specially designed for rotating applications in extreme environments that resist harsh wear and prevent the entry of harsh, abrasive outer media.
The head has a springloaded, highly polished, very flat face that is also frequently pressureloaded against that same seat face. This video is about different types of mechanical seal based on its design. This seal design was amount the first single spring seals and proceeded the slightly less expensive type 21 seals. A mechanical seal is simply a method of containing fluid within a vessel typically pumps, mixers, etc. Our offered seals are gadgets that assistance combine frameworks or instruments by counteracting spillage in a pipes framework, containing weight, or.
Spring retainer positions and centers the spring, aiding the concentricity between the spring and shaft. Sealing systems for pumpssealing systems for pumps part i. This allnew cr seals handbook from sf combines or best ideas and insihs from he ast and he resen we hoe i beomes yor. Bulletin number twentynine selecting mechanical seals. Mechanical seals come in a wide range of designs however the most important factor when determining how long a seal is going to last, is deciding on the right seal face materials. Sealing systems for pumpssealing systems for pumps part ii presented by. For double mechanical seals backtoback en specifies the short type only. There are more complex designs with double, tandem or other arrangements which place a barrier fluid between seals such that one of the seals is exposed only to the barrier fluid while the inner seal s are exposed to the liquid being pumped. Lts or lqt reservoirs, or elements such as cyclones.
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