Types of mechanical seals for pumps pdf

Shaft seals can take many different forms, but all serve the common purpose of keeping the liquid in the pump. We are the fastest in the country at moving products from the research and development phase to manufacturing and commercialization. Introduction to failures failure of the mechanical shaft seal is the most common cause of pump downtime. Mechanical seals are designed to handle a range of motions and conditions, but they are just one machinery component in a larger system. Probably the most widely recognized and also most common mechanical seal used in general service, low pressure applications.

Mechanical seal types rotary shaft seals uk seals ltd. As mechanical seals can be used to seal a myriad of different products on an equally vast array of equipment, we will be primarily focusing on the use of mechanical seals on rotating shaft pumps. The fact of the matter is that there are three types of problems mostly encountered with centrifugal pumps. At utex, we refer to this type as rs1 the assembly shown in the pump is configured with a. Different types of pumps mechanical seal piping plans are detailed in api 682 or iso 21049 standards. 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. Sealing options though often overlooked, shaft sealing selection can be just as critical as pump selection. For additional information please see the liquid containment paper in the applications section.

The obvious function is that of a check valve to prevent liquid under pressure from leaking out of the pump, or from drawing air into the pump when under vacuum conditions. Mechanical seals for pumps how mechanical seals work. Mechanical seals and more sealing technology by eagleburgmann is used worldwide in oil and gas industries, refineries, the petrochemical, chemical, and pharmaceutical industries, food processing, energy, water, mining, paper, aerospace, and other industries. H and l types are typically singlespring seals, while the m types are multispring units. Seal type the mechanical seal shown in the pump photograph is a type 1 mechanical seal. Common types of pumps mechanical seal piping plans. Advanced mechanical seals for the complete range of slurry. A mechanical seal, figure 1, consists of a stationary member seat.

Sometimes operating conditions change to become quite different from the specific conditions for which the seal was intended. Cartridgepusher seal basically is installed with moving secondary seal. Symbols a area of sliding face a h area hydraulically loaded by medium pressure b width of sliding face. Types of mechanical seals and their characteristics are given below for your ease to choose the rightone for you. Ksb offers a wide range of perfectly fitting mechanical seals for any kind of application of these pumps. Spring retainer positions and centers the spring, aiding the concentricity between the spring and shaft. 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. 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. Spring provides positive pressure for sealing between the sealing faces. Grundfos has many years of experience with the development, production and use of mechanical shaft seals in pumps, and our solutions in this field are contributing significantly to our leading position within pump technology. Standard mechanical seals are usually component seals.

Years of extensive product development, field testing and successful operation in all types of conditions allow us to offer mechanical seals and support equipment. Mechanical pumps in mechanical pumps, the gas present in a vacuum system is transferred from a low pressure to a. This seal design was amount the first single spring seals and proceeded the slightly less expensive type 21 seals. Shelby scottshelby scott western region john crane incjohn crane, inc. Stbrgtb teflon bellow replaceable face mechanical seals are suitable for handling corrosive media with some solid contents. These shaft seals are commonly used in irrigation, swimming pools, waste water, pulp and paper, oil and gas, power generation, food processing, rendering, cosmetic production, and thousands of applications where a fluid needs to moved from point a to point b. 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. Types and features of multiphase pumps helicoaxial pumps centrifugal a rotodynamic pump with one single shaft that requires two mechanical seals, this pump uses an opentype axial impeller. Our seals are totally interchangeable with all other manufacturers equivalent seals. Quality mechanical seals mechanical seals can be found in centrifugal pumps pool and spa pumps compressors progressive cavity pumps gear boxes rotary lobe pumps gear pumps slurry pumps jet pumps submersible pumps petrochemical pumps turbine pumps. Sealing systems for pumpssealing systems for pumps part i. In others seals must be designed for evolving industrial demands. Single seals made up of two flat surfaces that slide against each other and are pressed together by a spring. Cartridge, balanced, unbalanced, conventional, pusher, non pusher.

This portable document format \ pdf \ file contains bookmarks, thumbnails, and hyperlinks to help you navigate through the document. With our free email newsletter excellence in practice, you will receive firsthand information about current products, services, references and worthwhile industry insights. The shaft seal is exposed to widely varying operating conditions. Mechanical seals areused throughout industryto minimizeor eliminate leakage in centrifugal pumps, mixers, and other rotating equipment. Sarbs pump maintenance seminar, june 7, 2012 seal typesseal types causes of seal failure piping plans. A mechanical shaft seal consists of two main components. Mechanical seals types and installation part 1 our blog our facebook page. Pumps of this type are called double volute pumps they may also be referred to a split volute pumps. For most pumps a decisive element for the quality of the pump during its lifetime is a good and robust shaft seal. Mechanical seals types and installation part 1 youtube. Instead the torque is driven along the rubber bellow which fits on the shaft.

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. Also, in case of any mechanical failure or physical damage of pump internals, the operating engineer should be able to relate the failure to the process. Braided or formed rings that are compressed in the stuffing box of the pump. Mechanical seals are designed to overcome these drawbacks. The mechanical shaft seal is essentially a throttle arranged around the shaft. The rotating part is axially pressed against the stationary part. Since our subject is dealing with pumps, lets first explore a basic. Seal faces can be lubricated by the process fluid or, with double mechanical seals, by a proper auxiliary fluid see chapter relevant to configurations. Pumps with mechanical seals perform more efficiently and undoubtedly have much more reliable performance for extended periods of time. Figure 1 shows a typical centrifugal pump, which highlights its constituent parts, including the mechanical seal.

Of course the most common mechanical seal is a single spring seal. An stable and complete layer of lubrication greatly affects the performance and the life of a mechanical seal. Guidelines for selection, application and operation is intended to assist in understanding the general layout, components, and operation of a typical water treatment plant, and provide the guidance necessary to select pump types and define pump materials to perform effectively, efficiently, and reliably in the. It reduces leakage between the pump and the surroundings to an absolute minimum.

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. If you are unable to identify the seal, it will be necessary for you to. Centrifugal pumps can also be constructed in a manner that results in two distinct volutes, each receiving the liquid that is discharged from a 180. This type of seal has face which can be replaced if damaged. Mechanical face seal replacement how to use this catalogue locate the manufacturer of the equipment.

A number and a code indicate the configuration and materials used in each torishima mechanical seal. The fundamentals 5 alpha alpha unavoidable phenomena like vibrations, misalignment and shaft runout and for this reason its called dynamic fig. The seals are classified as h, m or l according to load, with h and m indicating heavy load and l indicating light load. Slurry seals advanced mechanical seals for the complete range of slurry applications. Perfect sealing solutions for ksb standardised chemical pumps. Introduction the mechanical seal acts as a check valve and a slider bearing. We also provide a huge range of equipment specific mechanical seal replacements for all major global pump manufacturers. The flexible bellow accommodates shaft run out without causing any damage to the whole seal. Its often called a poseidon pump, and can be described as a cross between an. Mechanical seals move the point of the seal away from the shaft to specially designed sealing faces that gradually wear down.

Dec 29, 2012 types of mechanical seals and their characteristics are given below for your ease to choose the rightone for you. Mechanical seals explained the basics mechanical seals are leakage control devices, which are found on rotating equipment such as pumps and mixers to prevent the leakage of liquids and gases from escaping into the environment. Common types of pumps mechanical seal piping plans single seals. Review different pump types commonly used understand the difference between centrifugal pumps and positive displacement pumps understand the working principle of the tuthill. Incorrect installation and adjustment are the causes for failure. 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. Common types of dual seals are addressed in another article. Uk seals supply all common industry standard mechanical seal types and dimensional standards. Mechanical seals according to en 12756 code system for single mechanical seals there is a distinction drawn between standard n and short k types. Sealing systems for pumpssealing systems for pumps part ii presented by.

Its often called a poseidon pump, and can be described as a cross between an axial compressor and a centrifugal pump. The materials of seal construction, particularly the sealing faces and elastomers. There are various types and arrangement of the mechanical seals being used for the centrifugal pumps. Mechanical seals are engineered for most pumps, mixer and agitator applications in maintenance. Single spring seals were invented in the 1900s by george cook far before john crane, burgmann, chesterton, borg warner. For double mechanical seals backtoback en specifies the short type only. We develop and produce customerspecific special and individual solutions for every application. Mechanical seal working animation types of mechanical seal. The portfolio includes standardised seals according to en 12756 for low and middle requirements as well as single acting and double acting cartridge seals for high end applications. Single spring seals were invented in the 1900s by george cook far before john crane, burgmann, chesterton, borg warner, durametallic, flowserve, pac seal, u. Here are the most commonly used shaft seal options for pumps. Today, we provide a wide range of mechanical seals for applications requiring high levels of safety and quality, such as mechanical. Most common types of pump seal piping plans for single seals are discussed in following paragraphs.

This is an internal recirculation from the pump discharge into the seal. Mechanical seal types range from the simple to the complicated. 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. Mechanical seal technology and selection eagleburgmann. The three types of flow through a centrifugal pump are radial flow, axial flow, and mixed flow. This document is intended to clarify what to expect on mechanical seals found in colfax products. A mechanical seal is a shaft sealing device, which forms a running and dynamic seal between the. 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 manufacturer listings are alphabetical, refer to pages 7.