Dry mechanical seal pdf merge

Symbols a area of sliding face a h area hydraulically loaded by medium pressure b width of sliding face. Outboard of the dry gas seal is a barrier seal, which separates the gas seal from the compressor shaft bearings fig. This is essential when pumping or mixing a dangerous or toxic substance. Fundamentals of fluid sealing can also be found in a textbook by mayer ref. Containment seals are the outer seal in a dual unpressurized seal arrangement. No decomposition if used according to specifications.

The best way to ensure that your mechanical seal is performs at its best, is to select the seal properly and have the appropriate flush plan to support it. A detailed analysis of mechanical seals in use in exploration and production activities. Instead, the lubricating liquid will vaporize as it crosses the seal faces. Top entry mixers and bottom entry agitators on sealed tanks will have some sort of mechanical seal. John cranes comprehensive range of dry gas mechanical seals are designed to provide you with the correct seal solution suited for your specific application, to ensure optimal reliability, safety and performance. Presentation on mechanical seals sealwell india was estd. For double mechanical seals backtoback en specifies the short type only. A representative layout of a dry gas seal assembly and basic seal parts are shown in figures 4 and 5. We are committed to providing the latest technologies and designs in order to provide our turbo machinery customers within global energy industries with the solution. For example, applying this formula to a moderatespeed application with a sealing pressure of 3,118 psig and a speed of 7,700 rpm results in an estimated. Tsurumis new oil lifter device was developed to improve seal reliability and lubrication. Mechanical sealmixer application data sheet customer contact info company.

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. Here are 6 of the most common reasons mechanical seals can fail. Eagleburgmann mechanical seals combine the elasticity of the core. This integral system was a technological advance that allowed manufacturers to take responsibility for the entire sealing system and not just the seal. The inboard or, primary seal keeps the product in the pump housing. Chemical stability thermal decomposition conditions to be avoided. For many sanitary process vessels, the mixer must have some type of sealing barrier to provide either a dust tight vapor seal, a pressure tight seal to allow pressure or vacuum in the mixtank, or an aseptic sealing device to provide a hygienic seal between the tank id and the. In vertical installations, the secondary seal chamber is selfventing to insure proper lubrication of the secondary sealing faces. For a more complete description of dry gas seal principles of operation, see shah 1988. 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.

Dry gas seal systems for centrifugal compressors page 2 of. Correct seal setting is important in the successful operation of a mechanical seal. The difference between single and double mechanical seals. In a mechanical seal, the face that cannot move in the axial direction. Outboard of the dry gas seal is a barrier seal, which separates the gas seal. We provide tailor made mechanical seal irrespective of type, size and m. Drygas mechanical seals set a new standard in deepwater.

Secondary seal nbrepdmviton spring and punched parts steel working conditions mediums. This course is designed to provide an understanding how dry gas seals operate and. Clearance seals labyrinth and restrictive ring seals oil seals mechanical contact and liquid film seals selfacting dry gas seals. A study aimed at seal selection efficiency for centrifugal pumps in the oil and gas industry is presented. Care must be taken to insure that barrier fluidsare compatible with low temperatures. The seal nomenclature used is that adapted by the asle seals technical committee ref. And then a new seal comes onto the market called the dry gas seal and the new seal technician explains the logic why we need to develop an intimate. Being one of the top dry running shaft seals and dry running mechanical seal suppliers, manufacturers and exporter, we offer both the dry. The softer mechanical seal face usually has a smaller mating surface and is commonly called the wear nose of the mechanical seal. The advantages of dry gas seals over wet seal systems can be defined as follows.

The seals are classified as h, m or l according to load, with h and m indicating heavy load and l indicating light load. Probably the most widely recognized and also most common mechanical seal used in general service, low pressure applications. General installation and operating instructions for. By drying, we mean the removal or reduction of the liquid content in a.

Elimination of the wet seal system improves operational safety by eradicating any dangerous build up of hydrocarbon gas in the seal oil. Three new seal types were introduced in the second edition. Just like you may want a clean desk and a comfy chair, mechanical seals appreciate good working environments too. Shaft end seals are provided to restrict or prevent process gas leaks to the atmosphere or sealing fluid leaks into the process gas stream. An absence of this fluid film dry running of the pump results in frictional heat and ultimate destruction of the mechanical seal. Mechanical seals tend to leak a vapor from the high pressure. Packing cartridges combine quick and easy installation with robust simple. A flush plan is a strategic equipment arrangement that circulates fluid to.

With no contacting surfaces, dry gas seals are extremely reliable, reducing downtime and unplanned maintenance expenses. Under the right conditions, mechanical seals can experience thermal shock and shatter within 30 seconds. Dry gas seal systems for centrifugal compressors page 2. Mechanical seals in mechanical and thermal separation processes. Pdf dry gas face seal design with arbitrary gap shape. Robert flitney, in seals and sealing handbook sixth edition, 2014. Replacing the wet seal with two tandem dry seals can reduce emissions between 34 to. A dry gas seal is essentially a mechanical seal with a rotating mating ring and a stationary seal ring. Dry gas seals dgs used in ultrahigh pressure gasreinjection systems are setting a new standard in offshore, deepwater applications. This article will explain what a mechanical seal is and the key design features that make them work.

Mechanical seal technology and selection eagleburgmann. The seals of the industrial age were organic ropes or packings. Run dry provides a gland on the backside of the mechanical seal through which a lubricant can circulate providing lubrication and cooling to the hardened seal faces of the mechanical. What is a double seal and when to use one double seals. Mechanical seals for mixers and specialty equipment. As part of the german freudenberg and japanese ekk group, eagleburgmann is one of the worlds leading providers of industrial sealing technology. Therefore standard mechanical seals are used only for a pressure up to 10 bar. These seals virtually eliminate leakage of the fluid or gas being handled in pumps or mixers. In order to comply with emission regulations and maintain an absolutely tight seal to prevent natural gas from leaking from the mechanical seals, the seals had to be pressurized exter. For higher pressures, balanced mechanical seals are used. This is commonly seen in centrifugal pumps although this challenge also exists in other equipment such as agitators, turbines, compressors, centrifuges, and. Each topic covered includes, where possible, a reference wherein more information can be found. Components dry gas seals dry gas seals, an alternative to isosleeve and isocarbon seals, eliminate the need for oil supply systems. Mechanical seals areconstructed of a wide range of materials.

A sealing system for hydrocarbons must often make allowance for partial dry running due to their low. The dynamic sealing surface was incorporated into the seal assembly. Dry mechanical seal are designed for agitators, mixers, reaction vessels, blowers, fans, etc. The liberator ii is a double hydraulically balanced seal which allows it to be used as a double or tandem seal. Other times, failure is a result of poor selection or installation errors. Dry seal tm mp safety data sheet according to regulation ec no. Field applications of dry gas seal designs were completed in 1952. Learning is through an effective blend of classroom theory sessions and practical handson exercises.

This paper describes the development and test of a cartridge type mechanical seal combining the ability of dryrunning with abrasive resistance. Such seals are available for use with a variety of compressed systems, including in harsh environments where other seals might be prone to failure. Turbomachinery sealing solutions flowserve corporation. These seals are available in both metal bellows and oring pusher styles and feature plainface or texturedface vari.

John crane training john crane mechanical seals, seal. At utex, we refer to this type as rs1 the assembly shown in the pump is configured with a. A mechanical seal that operates with gas as the lubricant. Mechanical seal selection fristam has many years of experience in the manufacture of mechanical seals and is able to provide the best mechanical seal for any application. Unlike an oring seal, the hydraulic diameter of a bellows seal is not a fixed geometric value. Included in this list is the selection of the materials of construction of the seal.

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. Mechanical seals are designed to handle a range of motions and conditions, but they are just one machinery component in a larger system. A high velocity fluid water or steam strikes the blades of the turbine, inducing rotation. The fc seal is a contacting, dry running seal which can be added to most of flexa seal s single cartridge options, including. Read more about reasons why mechanical seals selfdestruct on our blog. This includes detailed coverage on the seals applicable to static, rotary and reciprocating applications, the best materials to use in your. Mechanical seals in mixing and separating processes in the. With proper application and design however, the leakage is so minute that actual droplets of liquid are not detected. Aesseal has developed a range of pump dry gas seals to suit. Sometimes operating conditions change to become quite different from the specific conditions for which the seal was intended. Towards the universal mechanical seal for industrial pumps grundfos.

The seal ring which rotates with the shaft is called the rotary ring. John crane is an american company, now a subsidiary of smiths group and provider of engineered products and services including mechanical seals, couplings, hydrodynamic bearings, seal support systems, filtration systems and artificial lift. This high speed turbine is interconnected to the armature of a generator. In the late 1920s, a self contained shaft seal was created from oil resistant leather assembled into a metal case. The use of a thermal spool andor a wet seal with flushplan 54 may drive the elastomers into an acceptable temperature range. A seal in which the clearance between the shaft or rotating seal component and the nonrotating seal component is geometrically. May 28, 2012 mechanical seals a mechanical seal is a device which helps join systems or mechanisms together by preventing leakage e. The application of dry gas seal system is recommended. Mechanical seals first in a series by ann attenasio.

The seat seal face is exposed to the gases vapors of the product and there is no liquid coming in contact with the seat and face. The cornell run dry system is an inventive solution to provide continual lubrication of mechanical seals. By using an empirical formula for dry gas seals in highdensity fluids based on the bilgenboulos equations for high reynolds numbers, estimating an applications churning heat is possible. A mechanical seal, figure 1, consists of a stationary member seat. Dry gas seal a major manufacturer of centrifugal gas compressors had received an order for several large systems for an overseas cogeneration plant. Inboard of the dry gas seal is an inner labyrinth seal, which separates the process gas from the gas seal. Pdf analysis of mechanical seals for highspeed centrifugal. Mechanical seals according to en 12756 code system for single mechanical seals there is a distinction drawn between standard n and short k types.

A paper mill, oil refinery, thermoelectric power plant, pharmaceuticalchemical plant, or. Like packing, the mechanical seal faces must also be lubricated. The shaft seal is exposed to widely varying operating conditions. 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. 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. Apr 27, 2011 common dry gas seal failures are discussed below along with their causes and remedies. Allowing the pump to run dry allowing your pump to run dry can be very damaging to a mechanical seal. This greatly increases reliability and reduces seal maintenance to a minimum.

The simplest and most efficient method to insure that the. Introduction to failures failure of the mechanical shaft seal is the most common cause of pump downtime. The gaspac integrated rotor seals combine the rotating face and sleeve into one part, decreasing the amount of axial space required for a dry gas seal. A mechanical seal is simply a method of containing fluid within a vessel typically pumps, mixers, etc. B09xu range internal bellows mounted mechanical seal. Top entry, split mixer seal vra top entry, dry running single mixer seals equipment type mixers, agitators operating parameters pressure up to 6 bar 90 psi temperature 18 to 150c 0 to 300f speed up to 1. These mechanical seals are being installed on compressors at the tupi 4 floating production. The three principal types of dry gas seals for turbomachinery applications are discussed in the following paragraphs. Optional leakage management systems for arrangement 2 are plans 52, 71, 72, 75 and 76. Mechanical sealmixer application data sheet customer contact info. Dry containment seal features a dry containment seal is similar to a traditional mechanical seal, except the design and materials of construction are selected to negate the need for liquid lubrication at the sealing faces.

Predicted leakage rates all mechanical seals require face lubrication to achieve reliability. They have less mechanical loss than oil seals, improving efficiency. Klozure mechanical seals fill in dimensions styl e 01 oring seat styl02 tsh ap eds t style 04 cup mounted seat style08 lsh ap. Vulcan type 24, burgmann mg912, john crane type 521, roten type 52 12 14 16 18. 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. Dry gas seals are noncontacting, dry running, mechanical face seals comprising a. The original patent was for kaydons tapered ramp lift geometry, a constant diameter variable depth dynamic lift design. Dry running seal dry running mechanical seal and dry. With a lower k value, the safety against thermal overload will increase, but the mechanical seal may also lift off more easily.

This fluid film prevents the mechanical seal from touching the stationary ring. In case of the existing compressor equips oil film seal, seal oil console shall be replaced with dry gas seal control system. Dry gas seals are noncontacting, dryrunning, mechanical face seals comprising a rotating mat ing ring and a stationary primary ring. In systems with highly corrosive fluids, are recommended mechanical seals with external springs. The outboard or, secondary seal prevents leakage of the. Dry running mechanical seals manufacturer authorstream. We manufacture certified dry running mechanical seals to comply with fda and cgmp requirements for all industrial mixing applications. Standard mechanical seals in conformity with din 24 960 can be mounted without problems. These mechanical seal are a result of two decades of experience in design, manufacture and operation of seals. Cartridge seals unitize the complete seal assembly on a sleeve such that the entire seal is. These pioneering techniques have led to sophisticated seal face topographies and innovative microfeatures that can be designed to boost. Doing this created a series of lips with horizontal as well as vertical contact points.

Double or dual mechanical seals are designed to ensure maximum sealing safety. 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. Dry gas seals are noncontact, dry running mechanical face seals that use a sealing gas to create a barrier between the process gas and the atmosphere. Double seals provide a level of safetyzero emissions compliance not possible with single seals. About us at the leading edge of industrial sealing technology. In this case two mechanical seals are arranged in series. A dry gas seal is a mechanical seal that uses a sealing gas to create a barrier between the process gas and the atmosphere. Vinogradov and others published dry gas face seal design with arbitrary gap shape find, read and. In the case of a dry running containment seal, the. Inadequate fuel gas pressure during start up typical conditions on inboardoutboard seal will include running. Mechanical seal operates in contact with product depending on process level low process levels in vessel cause blade slapping on liquid surface and bounce shaft and seal shafts, impellers, and seals operate at side of vessel shafts are shorter, run. 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. These seal are best suitable for application involving abrasive, corrosive and viscous fluids.

To install a seal, the pump would have to be taken offline and disassembled. These seals proved to be very effective until shaft speeds, temperatures and other parameters increased with the development of better transportation systems. Seal basics a mechanical seal is a device used to seal the interface between a rotating shaft and a stationary housing figure 1. They consist of a turbine connected by a drive shaft to an electrical generator. A submersible pump has a mechanical seal to protect the dry motor from water. 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. The barrier fluid at the secondary seal is on the o. The mechanical seal division of the fsa is one of six divisions with a specific product technology focus. Dry gas seals are designed with many of the basic characteristics of liquid mechanical seals and can therefore be potentially subject to similar failure modes.