mechanical seal diagram brands

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Mechanical seals are critical components in centrifugal pump systems. These devices preserve the integrity of the pump systems by preventing fluid leaks and keeping contaminants out. Mechanical seal systems are used on various seal designs to detect leakage, control the seal environment and lubricate secondary seals.

Depending on the pump type and the process variables, there are various mechanical seal types to choose from. Each seal variant has its unique design and characteristics which make it suitable for a specific application. MES has years of experience with industrial mechanical seals and support systems, making us an authority in this area.

Mechanical seal types vary in design, arrangement, and how they disperse the hydraulic forces acting at their faces. The most common seal types include the following:

Balanced mechanical seal arrangements refer to a system where the forces acting at the seal faces are balanced. As a result of the lower face loading, there is more even lubrication of the seal faces and longer seal life. Learn about our mechanical seal lubrication systems today.

Balanced mechanical seals are particularly suited to higher operating pressures, typically above 200 PSIG. They are also a good choice when handling liquids with low lubricity and higher volatility.

Unbalanced mechanical seal types are commonly employed as a more economical option to the more complex balance seal. Unbalanced seals may also exhibit less product leakage due to tighter control of the face film, but as a result can exhibit much lower mean time between failure. Unbalanced seals are not recommended for high pressure or most hydrocarbon applications.

Pusher seals utilize one or multiple springs to maintain seal closing forces. The springs can be in the rotating or stationary element of the mechanical seal. Pusher type seals can provide sealing at very high pressures but have a drawback due to the elastomer under the primary seal face that can be subjected to wear as the face moves along the shaft/sleeve during operation.

Non-pusher seals utilize a metal or elastomeric bellows to maintain seal closing forces. These seals are ideally suited to dirty and high temperature applications. Bellows seals are limited to medium/lower pressure applications.

Conventional seals are typically lower cost and often installed on general service equipment. These seals require higher operator skill to service as they installed as individual components.

Cartridge type mechanical seals incorporate all of the seal elements into a single assembly. This dramatically reduces the potential for assembly error and the time require for seal replacements. Learn more about the difference between cartridge and non-cartridge mechanical seals today.

When deciding on the type of seal system for a centrifugal pump, operators must choose according to their unique application. Failure to select the proper seal type can lead to loss of pump integrity, breakdowns and costly repairs. To avoid these undesirable results, all operators must consider the following factors before deciding.

The amount of pressure exerted at a mechanical seal’s faces has a significant effect on its performance. If a pump is to be operated at low pressures, an unbalanced mechanical seal will be suitable. However, in conditions where higher pressures are anticipated, balanced seals will prove a more reliable solution.

Balanced mechanical seals perform better than their unbalanced counterparts in conditions where the operating temperatures are higher than normal. Heat sensitive components are better preserved in balanced mechanical seals compared to other seal types.

As it goes for all types of machinery, operator safety is the top priority. The use of double mechanical seals in centrifugal pumps provides additional protection as they have increased sealing capacity and are generally more reliable.

The scope of our mechanical seal product range far exceeds any other seal manufacturer. From small elastomer bellows seals used in millions of domestic water pumps to double mechanical seals that ensure maximum sealing safety and large, highly customized dry-running gas seals for mission critical high speed turbo compressors, John Crane has the right product for any application.

Our world-class rotating equipment technologies, paired with an unmatched breadth of applied engineering expertise, meet virtually all international standards including API 682 and help plants reduce maintenance costs, slash down time and improve reliability. When it comes to keeping your rotational equipment running 24/7, John Crane’s comprehensive range of mechanical seals and systems has you covered.

A range of seals for mission-critical applications, designed to solve the application-specific challenges of each industry. From API 682 compliance for the oil and gas industries, using gas seal technology on our innovative pump gas seals to eliminate fugitive emissions, dealing with slurry in the mining and minerals processing industries, to the difficulties associated with maintenance on large pumps and rotating equipment — we have a solution.

Dry-running, non-contacting gas seals have been the industry standard since the early 1980s for turbomachinery. John Crane gas seals, separation seals and support, monitoring, control and conditioning systems — the heart of any reliable sealing solution — are constantly evolving to meet the needs of customers. The product portfolio is supported by unrivaled global service capability providing repair, retrofit, gas seal storage and reliability expertise, delivering total solutions throughout the product lifecycle.

In industries like chemical, pharmaceutical, pulp and paper, and food and beverage, safeguarding and compliance with industry standards, avoiding contamination and efficiency are always top priorities. Our range of vessel and agitator seals optimize equipment performance, maintain product purity and conform to industry regulations, no matter where you are.

Our range of mechanical seals, packing and bearing isolators combines advanced, thoroughly proven technologies with extensive industry expertise to create a range of products characterized by innovative design concepts and outstanding manufacturing quality. Tried, tested and effective solutions for virtually any application that deliver robust performance, reduced installation times and lower maintenance costs.

Create the optimum operating environment that will ensure outstanding seal performance and reliability. Our comprehensive range of engineered pressure reservoirs, gas seal control panels, heat exchangers and abrasive separators can be combined to produce the perfect seal support system for any application.

Designed to overcome rigorous challenges, our comprehensive suite of seal face technologies combat limited seal face lubrication that adversely affects reliability, cost and durability. Our engineers designed these face treatments to extend rotating equipment life through advanced micro machined patterns and features improving seal face lubrication that optimizes equipment performance. We deliver the right face technology for the right application.

... pressurized gas barrier metal bellows seal utilizing APGS non-contacting seal face technology. Welded metal bellows eliminate dynamic O-ring hang-up in a compact cartridge that fits ANSI and DIN standard ...

• Drive mechanisms external to the product;• Seal faces positioned for maximum protection;• A dynamic elastomer moves on a non-metallic surface, eliminating fretting defects;• Hydraulically balanced;• Cartridge easy to ...

Burgmann H74-D Mechanical Seal called as PC04 are specialized in mechanical seals products. This device gives double seal and it can be rotated in any ...

The MTM10-11 is a conical spring mechanical seal developed by Microtem. It is mainly used for general services machinery at low and medium pressure. This unbalanced mechanical seal ...

The MTM 25_26, manufactured by MICROTEM, is a conical spring mechanical seal that can compensate positioning errors and withstand stresses created by vibrations. The contact surface can be made with silicon ...

... agitators on sealed tanks will have a mechanical seal of some sort. For many sanitary process vessels, the mixer must have some type of sealing barrier to provide either a dust tight vapor seal, ...

mechanical seal for automotive engine cooling water pump, referred to as water seal, mainly composed of two parts: rotating ring and static ring. Static ring is installed in the pump ...

The 3-D Seal is designed to be the foremost solution for high radial misalignment and high run out applications. By combining Garlock’s proven P/S®-II and expansion joint technologies into ...

Aura™ reduces operational and transactional costs using a patented polymeric sealing device. Aura reduces leakage rates by up to 15 percent, lowering the total cost of operation while protecting the environment. An enhanced rotor design ...

The AESSEAL® API Type A, B and C single-seal range offers the user an unprecedented range of API engineered sealing solutions to suit all application ...

Mechnical seal type 5030 / 5031 »with rubber bellowssingle-actingnon-anisotropicAreas of usestandard pumpwaster water pumpsupply engineeringgeneral industrial usemass production seal

When purchasing the units, if left hand rotation, special seal, or a particular position of cartridge (shaft end or cover end) is needed, it should be ...

Cartridge Seals by CinchSeal are customized mechanical seals for rotary air locks in bulk handling equipment. They are designed to replace lip and packing seals in screw ...

An end-face mechanical seal is a device used on a rotating shaft to keep fluids in and contaminants out. It prevents the fluid moved through an asset, most often a centrifugal pump, from leaking. These seals are located in the asset’s stuffing box or seal chamber. This is the area of the pump where the pump shaft connects to the drive (an electric motor, for example).

Except for air seals, which will be discussed later, most types of mechanical seals consist of two flat faces that are installed perpendicular to the shaft. One of the faces is mounted stationary to the seal chamber housing. The other face rotates with the shaft to provide the primary seal. Axial mechanical force and fluid pressure maintain the contact between the seal face materials. This contact prevents leakage and retains the fluid within the pump.

Component, end-face mechanical seals consist of a separate rotating member and a stationary seat that mount in a gland or housing. Since they are not preset, installation and maintenance are more complicated than cartridge seals. Installing these requires experienced technicians who can properly install and adjust them.

Air seals are noncontacting, pneumatic devices engineered to seal rotating shafts. These seals are primarily installed in dry powder or slurry applications. They protect against product loss, emissions, and contamination by using small amounts of air or inert gas. This air is throttled to create positive pressure and an effective seal.

Most mechanical seals have five parts:Rotating primary face– Fixed to and rotates with the shaft and seals against the stationary primary sealing element

Stationary primary face– Fixed to the stationary housing of the pump, mixer or other equipment through which the rotating shaft passes and seals against the rotating primary sealing element

Mechanical loading devices– Biases the primary sealing elements in contact to initiate sealing. These can be a single spring, multiple springs, wave springs, or metal bellows.

Static and/or dynamic secondary seals– Seal between the mechanical seal components and the equipment shaft and housing that compensates for any shaft movement that may damage the seal faces.

In summary, knowing the mechanical seal types and the parts that make them up is only the beginning. Assessing the application, installation, and operation (with leakage limits) helps determine which seal type will be selected and how well it will perform in the system. This important decision factors into overall system reliability.

Mechanical seals are end-face seals that use a pair of faces perpendicular to the rotating shaft (sliding surfaces) to seal. The sealing faces, smoothly finished with high accuracy, enable long-term maintenance-free usage.

Mechanical seals manufactured by Eagle Industry Co., Ltd. are products achieving excellent performance and low running costs that feature highly accurately finished flat sealing faces, enabling long-term maintenance-free usage.

Mechanical seals withstand usage in various applications in different pumps for automobiles, households, civil engineering and construction, and in processing and chemical fields such as petrochemicals, nuclear energy, and space development, and have a wide range of use.

Double mechanical seal - This is where two mechanical seals are used within a pump. The first seal retains the fluid within the pump as per the standard mechanical seal above. The second seal contains a barrier fluid to ensure the faces are kept clean and are lubricated preventing failure. Without such liquid, the mechanical seals would run dry and fail.

Cartridge seal - When a mechanical seal is first inserted within a pump its clearances should be set. By utilising a cartridge clearances do not need to be set as the unit is pre-assembled eliminating the need for time-consuming assembly and spring setting on site.

Packed gland - A packed gland is when a braided material which has an appearance similar to a flat rope is wrapped around a shaft. A packed gland is also known as stuffing as the packed gland is typically wrapped tight around the shaft and inserted within a chamber known as a stuffing box. Packed glands must leak a little to allow cooling from immediate contact with the shaft to prevent burning, and over time do wear shafts. Packed glands were used more historically as they were utilised before mechanical seals were invented. They are still used in some boiler feed pumps where seal failure is common from overheating, cavitation or the presence of high fine solid content is expected as it is a cheap way to seal the pump rather than utilising expensive flushing liquids or double mechanical seals such as in dredging.

Expeller Seal -An Expeller seal is a shaft sealing arrangement where a rotating part called an expeller is mounted where gland packing or a mechanical seal is normally fitted. Its appearance is similar to that of another impeller, with rigid vanes mounted on the rear of a disc, which as it rotates reduces shaft pressure creating a dry seal around the shaft without a gasket or packing.

However once rotation stops, so does the dynamic sealing meaning a seal must be in place to prevent media leaking. This can be done by either external flush, packing, lip seals or an inflatable bellows.

An expeller seal is useful for slurry pumps used within mines at remote locations where a seal flush is required, which consume vast amounts of water. As water is scarce, and expensive in such areas sizeable savings can be made by switching to such a sealing arrangement.

Typically Mechanical seals are usually manufactured in Carbon Ceramic, with a Stainless Steel Spring. Carbon is a good general choice for the majority of applications where a fluid is compatible, not contaminated and fairly clean.

Hard faced mechanical seals are typically used when the fluid handled may be harsh, and contain solids. Such seals are usually made in Silicone Carbide or Tungsten Carbide due to its hard wearing construction it is built to withstand unexpected small solids such as Sand, dirt, stone and is a great choice for heavy duty applications.

Do you require replacement mechanical seals and gaskets? Suffering from frequent seal failure or replacement? We can help diagnose the cause and eliminate recurring failures.

More Durable & more suited for long term operationEasily DamagedMore forgiving than mechanical seals, accepting particles, and large shaft movements such as in the Paper & Mining Industry. Can continue to be used even when pump has experienced excessive wear.Requires replacement more often adding to wear and tear of pumps as they are assembled and disassembled. More labour intensive

Safer as double seals, or cartridge type can be fitted drastically reducing the possibility of leakageIf packing requires fresh water supply as a flush it can leak to contamination or dilution of the pumped liquid

The use of the word “seal” is a misnomer; as a mechanical seal is a restrictive flow path,that is either an angular or radial gap.The flow through this gap is generally so low it goes unnoticed if a liquid or inconsequential if a gas.

A mechanical seal works byretaining a liquid or gas inside a rotating piece of equipment. Mechanical seals can be designed to prevent contamination of the process by the environment and prevention of leakage of the process into environment.

The basic components of a mechanical seal are a Rotating Part and a Stationary Part. The primary seal of a mechanical seal consists of a rotating face and a stationary face. The faces are kept lubricated by maintaining a thin film of fluid between each face. There is a very small gap between these 2 components which creates a restrictive flow path.

There are other components namely o-rings or gaskets which are used as secondary seals and hardware which is used to support the seal faces and to attach them to the rotating part (i.e shaft) and stationary part (i.e cover plate).

The primary seal of a mechanical seal is made up of 2 seal faces where these two parts meet is where the seal gap is located. The mating surface of the seal face is machined to a very tight tolerance.

Double Seal (Barrier) => consists of two primary seals in various arrangements. There is a barrier fluid between the two primary seals which is at a higher pressure than the process. There is always some leakage of the barrier fluid in process & out to atmosphere. As long as barrier pressure is maintained there is no leakage of process to atmosphere or contamination of process by environment.

Double Seal (Barrier) – Wet => is a double seal where the barrier is a liquid. It is generally the most robust seal. It has a good pressure, speed and temperature capabilities.

Gas Contacting Seal– the seal faces are in contact, the soft face wear acts as a lubricant. Low pressure, speed and temperature capabilities and possibilities of wear getting into the process.

Gas Non Contacting Seal – the seal faces are NOT in contact. They are kept apart by a flow of gas between the faces. Good temperature, speed and pressure capabilities. If operated correctly their is no wear but care must be taken in order to minimise shaft run out.

Cartridge seal =>is where the rotating and the stationary hardware are pre-assembled before mounting onto the pump/mixer. Cartridge seals are much easier to fit & maintain compared to the component seal.

A lip seal is a specific type of seal, it is a radial seal, where the part that seals against the rotating surface is a narrow cross section, soft material i.e the lip and it is made from an elastomer or non-elastomer material with a backup spring. Most commonly used to seal bearings in Mixers/Agitators. A lip seal rotates too quickly to be used on pumps.

Abarrier fluid is any gas or liquid which is used to pressurise a double mechanical seal. It must be compatible with the process, generally non-toxic and a good lubricant.

Please consult the pump manufacturer/distributor for guidance on these calculations for mixer seals, the barrier pressure is set at a certain value above the maximum vessel pressure.

Packing is a material that is stuffed between a rotating shaft and a stationary part gland to maintain pressure. Packing is a low cost alternative to mechanical seals.

We supply mechanical seals into the pharmaceutical, bio-technology, chemical processing, mineral and ore processing, semi-conductor and general industries.

Depending on your particular application, if you are looking mechanical seals to suit a pump application; Mechanical Seal for Pumps, or if you are trying to source mechanical seals for an agitator or tank mixer; Mechanical Seal for Agitator, or perhaps you have a hygienic application in mind, take a look at our range of Mechanical seal for Hygienic & Aseptic applications.

Our Mechanical Seal specialists can advise you on the appropriate selection of a seal support system which will deliver years of reliable service and operating cost savings in the longer term.

If you have any query around how to install mechanical seals or have some concerns around seal failures, why not contact one of our seal specialists below to discuss it in more detail and find out how we can help solve your issues and get your process running reliably again.

​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Chesterton is the world leader in design innovation of split seals. Our innovative split seals have been used to seal thousands of process-critical pieces of rotating equipment with exceptional​​ ​results and many years of leak-free operations.

Chesterton was the first company to offer commercially-viable split seals for plant-wide use, which revolutionized pump sealing across industries. Since that time, we"ve launched a number of innovative split seal designs now used as a standard by companies around the globe.​ We offer shaft diameters ranging from 25-914​ mm (1-36 in.)​

​A split seal has components split into two equal halves which are secured as one unit on the seal shaft. The major advantage of the split seal design is that it allows you to install the seal with no dismantling of the pump (or equipment)—an enormous time-saver! Chesterton"s split seals offer virtually leak-free performance. This leads to improved safety and environmental compliance and nearly eliminates sleeve wear, and flush water usage,  among many benefits.