Double mechanical seal types pdf

Part 2 types of mechanical seal based on design balanced vs. H and l types are typically singlespring seals, while the m types are multi spring units. Double mechanical seal arrangement options double seals. It has been found that the pharmaceutical industry is unique enough, and large enough, to demand special. This is a very unique design that permits far more runout than traditional single cartridge or double cartridge seals. 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.

Sarbs pump maintenance seminar, june 7, 2012 type 21 type 1. Ttv oring fluorocarbon rubber fkm, double ptfe wrapped. The term seal is used to refer to a variety of products including notary seals i. In this type of seal often there are no metallic parts in contact with the.

An stable and complete layer of lubrication greatly affects the performance and the life of a mechanical seal. Double mechanical seals are offered in two arrangements. All information contained in the installationoperating manual must be observed. The bta2 features all carbon or high quality resin impregnated carbon, aluminium oxide 96 %, is stationary and the rubber bellows are glued on collar. One face is fixed to the equipment casing or vessel, while the other is fixed to the shaft and so rotates. It covers about balanced and unbalanced seal, pusher and nonpusher type of seal. Double mechanical seal is a combination of two seals mounted either backtoback, or single seal having sealing faces on both sides or tandem type. This gives rise to the alternative name radial face seal, pump seals or packings. Pdf unique failure mode for double mechanical seals api seal. Several factors play a role in the selection of a mechanical seal, the mechanical seal type, the materials used, and the manner in which a mechanical seal will be operated. 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. Double cartridge pump mechanical seal sealcon supplier.

This is essential when pumping or mixing a dangerous or toxic substance. Mechanical seals standard oem mechanical seals uk seals. There are many types of cartridge seals available, back to back, tandem, face to face, etc. 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. Sarbs pump maintenance seminar, june 7, 2012 seal typesseal types causes of seal failure piping plans sealinggg water usage safeunit flowmeters. Seal type the mechanical seal shown in the pump photograph is a type 1 mechanical seal. These mechanical seal are a result of two decades of experience in design, manufacture and operation of seals. A mechanical seal appears expensive to buy when compared with a packing ring, but properly installed a seal will run for many years. A case study of a fire caused by seal failure on a butane pump equipped with a cartridge type double mechanical seals is presented. This is commonly seen in centrifugal pumps although this challenge also exists in other equipment such as agitators, turbines, compressors, centrifuges, and. Mechanical seal types uk seals has a very extensive range of mechanical seal types. The assembly is preset so that no installed length calculations must be performed for determining where to set the seal.

The head is statically sealed to and rotates with a pump shaft. Suitable for a wide range of service conditions ranging from water and steam to chemicals and corrosive materials, the type 1 mechanical seal is ideal for use in pumps, mixers, blenders, agitators, air. Mechanical seals are designed to overcome these drawbacks. This allnew cr seals handbook from sf combines or best ideas and insihs from he ast and he resen we hoe i beomes yor. Mechanical seal education tutorials double mechanical seals. To install a seal, the pump would have to be taken offline and disassembled. Cartridge mechanical seals mechanical seals for any application we offer a range of standard inventory cartridge mechanical seals, including single and double seals to suit even the most demanding application and thanks to our modular design system we offer them with the best ontime delivery performance in the industry. The initial closing force ensures that the seal will function properly from startup. Mechanical seal guidelines for pharmaceutical applications introduction. These seal are best suitable for application involving abrasive, corrosive and viscous fluids. Symbols a area of sliding face a h area hydraulically loaded by medium pressure b width of sliding face. Mechanical seal technology and selection eagleburgmann.

One face is fixed to the equipment casing or vessel, while the other is fixed to the shaft. Two identical pairs of seal rings in a backtoback arrangement. Ideal mechanical seal for applications in the medium pressure range up to 40 bar abs. One solution is to mount the seal faces in a fashion that allows run out. The inboard, or primary seal keeps the product contained within the pump housing.

Text headings in each module are linked to and f\ rom the table of contents for that module. Part 2 types of mechanical seal based on design balanced. Double mechanical seals mean arduous service, an application where leakage cannot be tolerated. There are various types and arrangement of the mechanical seals being used for the centrifugal pumps. Torishimas mechanical seals mechanical seal applications mechanical seals the shaft seals used in rotating machinery such as pumps. Spread throughout the world, this type of mechanical seal has reached an unsurpassed quality level. Mechanical seals according to en 12756 code system for single mechanical seals there is a distinction drawn between standard n and short k types. Double cartridge pump seal is widely used in the media which is poor lubricated, toxic, flammable, explosive, volatile, containing abrasive and gas etc. Federal law dictates that these emissions must be contained. Type 1 elastomer bellows seals john crane mechanical. These seal specially designed for any mixed and pressurized liquid in vessel with top entry agitators where no leakage of highly acidic process. All mechanical seal types are available in a range of sizes and materials. For double mechanical seals backtoback en specifies the short type only.

You must consider the environment the seal will be exposed to. Nov 25, 2016 this video is about different types of mechanical seal based on its design. These seals virtually eliminate leakage of the fluid or gas being handled in pumps or mixers. This video is about different types of mechanical seal based on its design.

The modules listed in the overview are linked to the corresponding pages. 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. Please contact us for pricing and further information, including technical datasheets. Double or dual mechanical seals are designed to ensure maximum sealing safety. This philosophy exists in the mechanical seal industry. The typical single, single flushed and double flushed mechanical seal arrangements are described as follows. In part 1 of our series on double dual seals, we discussed the benefits of dual seal design and when to use it. This is accomplished by specially designed ends of the spring, which provide an interference fit. The radial double cartridge shaft seals structure is more compact than the axial double cartridge seal. A seal that fails early by this criteria is in need of investigation. The effectiveness of a seal is dependent on adhesion in the case of sealants and compression in the case of gaskets.

Its not just a cost issue but can mean danger for the environment, fire or explosion, or in the case of the shaft seal on a submarine, death by drowning. What is a double seal and when to use one double seals. 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. Cartridgepusher seal basically is installed with moving secondary seal.

Horizontal twinsuction axially split multistage volute pumps. Mechanical seals are one of the most effective ways of sealing rotating shafts, consisting of two lapped faces arranged perpendicular to the axis of the rotating 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. This is commonly seen in centrifugal pumps although this challenge also exists in other equipment such as agitators, turbines, compressors, centrifuges, and blowers. With its proven track record of exceptional performance, the type 1 elastomer bellows seal is widely recognized as the industrys workhorse. The old adage pay me now or pay me later applies to seals.

H and l types are typically singlespring seals, while the m types are multispring units. Double seal for glass lined reactor and double mechanical. Mechanical seal working animation types of mechanical seal. Our type 19 seal is unique in that the dual seal rotary seal faces run next to each other against a single stationary.

A double mechanical seal consists of two seals arranged in a series. 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 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. Pump shall be equipped with a pair of internally selfflushing mechanical seal assemblies plan 03 requiring no flushing lines. Torishimas mechanical seals mechanical seal applications mechanical seals the shaft seals used in rotating machinery such as pumps, hydraulic turbines, agitators and centrifuges play an important role in maintaining the safety and economic efficiency of machinery. Double seals can be arranged in tandem with the seats in the same direction on the shaft, or backtoback. Compact economical cartridge mechanical seal for glass lined vessel. The optimum life of a seal is the period between major overhauls of the pump unit. The head has a springloaded, highly polished, very flat face that is also frequently pressureloaded against that same seat face.

Double mechanical seal double mechanical seal arrangement should be used where a buffer zone is required between pump and atmosphere. The difference between single and double mechanical seals. Seal faces can be lubricated by the process fluid or, with double mechanical seals, by a. Use of the modular design opens up many different extension options. Types of mechanical seals and their characteristics are given below for your ease to choose the rightone for you. Double seals provide a level of safetyzero emissions compliance not possible with single seals.

The externally mounted mechanical seal on alfa laval pump ranges is also available as a double flushed mechanical seal for some pump models. Some are energized with metal bellows, while others are energized using multiple springs. The outboard, or secondary seal prevents the flush liquid from leaking into the atmosphere. Mechanical seal most commonly used in agitators worldwide. These seals can be singlecoiled or multi springs type besides they can have a combination of unbalance unbalance. Seal faces can be lubricated by the process fluid or, with double mechanical seals, by a proper auxiliary fluid see chapter relevant to configurations. The intent of the sealing industry is to offer crossover designs to the pharmaceutical industry building on existing proven designs. Mechanical seal types there are a number of mechanical seal types, each providing advantages for specific applications. This portable document format \ pdf \ file contains bookmarks, thumbnails, and hyperlinks to help you navigate through the document. Type 1 elastomer bellows seals john crane mechanical seals. These seals often use two rotating seal faces and two stationary seal. At utex, we refer to this type as rs1 the assembly shown in the pump is configured with a. Sealing systems for pumpssealing systems for pumps part i.

Suitable for a wide range of service conditions ranging from water and steam to chemicals and corrosive materials, the type 1 mechanical seal is ideal for use in pumps, mixers, blenders, agitators, air compressors, blowers, fans and other rotary shaft. Probably the most widely recognized and also most common mechanical seal used in general service, low pressure applications. Double cartridge mechanical seals mechanical shaft seals. Mechanical seals first in a series by ann attenasio. These seals can be singlecoiled or multi springs type besides they can have a combination of unbalance unbalance, unbalance balance or balance balance tandem types. Seal basics a mechanical seal is a device used to seal the interface between a rotating shaft and a stationary housing figure 1. Double mechanical seals are used in the pharmaceutical industry for a variety of reasons. A mechanical seal is a device that helps join systems or mechanisms together by preventing leakage e. Mechanical shaft seal types and sealing systems grundfos. The seat is statically sealed to a nonmoving cover. Sealing systems for pumpssealing systems for pumps part ii presented by. The preinstallation of the cartridge mechanical seal is simple and easy to operate. Mechanical seals allow a minuscule almost drop by drop leakage past the seal face to lubricate it to slow seal wear. Mechanical seal types industry standard or custom design.