rotary seals
- April 01, 2022
Gallagher Fluid Seals’ customer is a manufacturer of processing equipment that serves industries, including: food and beverage, automotive, pharmaceutical, and chemical. Their product lines include: fluid bed systems, coating and drying equipment, and mixer granulators.
Gallagher re-engineered the existing PTFE seal, made improvements to the lip geometry, and provided material selection guidance based on application parameters. The material change to UHMW-PE reduced seal wear, equipment downtime, and preventative maintenance.
- January 14, 2022
Custom Seals from Gallagher Fluid Seals
While you could buy seals made with the size and materials of industry standards, sometimes the performance may not be up-to-snuff. Whether you have a static or a dynamic application, each one has its own unique traits and characteristics. Rather than finding a product that "fills the needs" of your specific application, wouldn't it be more prudent to create the perfect solution?
Using custom-engineered seals from GFS, specific to your application, can help solve that.
Size
No matter the size, Gallagher can assist. Whether less than 1 millimeter or dozens of inches of diameter, our expert engineering team can help design the solution for the exact dimensions you need. Our ability to have the exact sizes and designs fabricated with our global partnerships can help you get it for the right price, too.
- December 09, 2021
Depending on the direction that squeeze is applied to the cross section on o-rings or seals, they will be categorized as an axial or radial seal.
Static Axial Seals
A static axial seal will act in a similar manner to a gasket that is squeezed on both the top and the bottom of an O-ring’s cross section. A static axial seal is used in face, or flange-type type applications. When it is used as a face seal and there is internal or external pressure, the O-ring should be positioned against the low-pressure side of the groove to cut down on O-ring movement and accompanying wear within the groove.
These seals are easier to design than static radial seals. This is due to the lack of extrusion gap and less design steps. That enables the user to more easily control the tolerances.
Static Radial Seals
- November 05, 2021
Split Clipper® Oil Seals have the same superior characteristics as solid general purpose Clipper Oil Seals, but are factory-split at one place in the circumference. This permits installation over the side of a shaft, rather than over the end, and often can save dismantling the equipment in order to replace the existing rotary shaft seal.
Solid Clipper Oil Seals should be used whenever practical to provide maximum bearing protection in rotating shaft applications. However, installing a solid seal in a failed application can be costly and time consuming. In such cases, Split Clipper Oil Seals can be used to minimize unscheduled downtime, specifically where equipment cannot be uncoupled. These seals will provide long and efficient service until major or scheduled machine overhaul permits convenient installation of a regular non-split seal.
Split Clipper Oil Seals are available in Series R, RPD and RUP profiles, depending upon shaft diameter. RUP and RPD profiles are general purpose
- March 03, 2021
Mobile cranes perform a wide variety of tasks, typically of the heavy-duty kind. The work they do and the locations at which they operate are frequently exposed to harsh climatic conditions in places with insufficient infrastructure. This means that the sites at which the cranes are positioned and the environment in which they move is often not entirely suitable for this kind of heavy construction equipment.
Accordingly, there are high loads acting on the components, which often wear out prematurely as a result. A new sealing solution for swivel joints in cranes subjected to high loads, which combines a polyurethane O-ring with a nobrox® backup ring, has effectively remedied this issue.
- January 26, 2021
When it comes to designing dynamic seals, the two most important application parameters are the pressure and the speed of the motion. These two factors chiefly determine the type of seal, design geometry, and seal materials you should choose.
When dynamic speeds and system pressures become elevated, determining the life expectancy of the seal becomes an important point of analysis. A seal that’s low friction, cost effective, and seals outstandingly is useless if it only lasts a few hours before wearing out.
To quickly gage the feasibility of a seal’s performance and provide a baseline metric, seal engineers use a calculation called Pressure-Velocity (PV).
Below we’ll explore what PV is, how it’s calculated, and what makes it an important tool in seal design.
What Is PV?
Simply put, pressure-velocity is the product of the pressure and velocity. In other words, the pressure of the system multiplied by the surface speed of the dynamic seal interface.
- September 01, 2020
When it comes to maintaining a high-functioning rotary shaft, you need to select the appropriate lip seal.
The shaft seal protects the rotary shaft from contaminants such as dust and dirt, and it keeps water out and lubricant in.
A rotary seal, also known as a radial shaft seal, typically sits between a rotary shaft and a fixed housing — such as a cylinder wall — to stop fluid leaking along the shaft. The rotary seal’s outside surface is fixed to the housing, while the seal’s inner lip presses against the rotating shaft.
Common applications for shaft seals include motors, gear boxes, pumps and axles. They’re also increasingly used for food and chemical processing, as well in pressurized gas applications.
Three of the most important considerations when the choosing the best lip seal for a rotary shaft are:
- The material the seal is made of,
- the hardness of the shaft’s surface, and
- the roughness of the shaft’s surface.
Here’s your quick go-to guide on how to achieve optimum performance and longevity for your seals and shafts, ultimately minimizing the risk of seal failure. Presented by our partners at Eclipse Engineering:
- August 29, 2019
Polymer wear rings were developed to offer an alternative to dissimilar metal wear rings.
One of the advantages to using a polymer material such as nylon or filled-Teflon instead of a metallic bearing . Whereas when you use bronze or metallic bushings, these materials are prone to point loading on the edges of the bearing.
This property of polymer bearings combined with solid lubricants can yield a product that is much less likely to damage moving components.
5 Advantages to Polymer Wear Rings
- Polymer style bearings can be held to very close tolerances in the radial dimension to provide support without excessively opening the extrusion (E) gap by a large amount. Polymer bearings such as filled Teflon can support a compressive load up to 1000 PSI. Nylons up to 36,000 PSI and polyester fiber with resin, up to 50,000 PSI.
- Hydraulic cylinders that are found in excavators often use higher compression materials because they experience extreme
- May 23, 2019
Mechanical sealing conserves water, improves energy efficiency, and minimizes environmental impact
The environmental performance of products and processes in all industrial sectors increasingly is cause for critical inspection, with sustainability, conservation of natural resources, and reduced environmental contamination concerns influencing equipment design and selection.
Many industrial processes can be addressed to improve sustainability and minimize environmental impact, while at the same time maintaining or reducing operating costs. Implementing energy-efficient and environmentally friendly processes and technologies should be embraced as a priority at the component, process, and system levels.
One aspect of these processes is mission-critical rotating equipment, and specifically centrifugal pumps, which represent a significant proportion of the equipment found in industrial operations. One vital component of a centrifugal pump is the seal around the rotating shaft that passes through a stationary pressure casing or housing. The seal contains the liquid or gas from escaping to the environment.
Sealing systems help maintain acceptable pump efficiency, reliability, energy consumption, water usage, and emissions control. These factors can materially facilitate achieving total-life cycle cost-reduction and sustainability objectives. Sealing performance can be improved for centrifugal pump applications by upgrading from traditional compression packing to mechanical seal technology.
When sealing a centrifugal pump, the objective is to allow the rotating shaft to enter the wet area of the pump without large volumes of pressurized fluid escaping. The pump discharge pressure forces the fluid back behind the impeller, where it is induced to exit by way of the rotating drive shaft. To minimize leakage, a seal is needed between the shaft and pump housing to contain the pressure of the process being pumped and withstand friction caused by shaft rotation.
Compression packing is the traditional means to seal centrifugal pumps, going back more than 100 years. Also referred to as gland packing, it is a braided, rope-like, and lubricated material packed around the shaft in rings, physically stuffing the gap between the shaft and the pump housing, within a stuffing box.
Water leakage and consumption
For compression packing to work, some leakage must be maintained to lubricate and cool the packing material. Therefore, packing rings allow for an adjustable, close-clearance leak path parallel to the shaft axis. As the packing is used, however, some of the lubricant that is embedded into the packing is lost, reducing the packing ring’s volume. The pressure squeezing the rings together is also reduced, increasing leakage.
Periodic adjustment of the packing follower brings the pressure back into specification and controls the excess leakage. In today’s world, however, this maintenance is not always being done at required intervals or adjusted correctly. As the number of centrifugal pumps incorporating the use of compression packing decreases, training for and understanding of packing maintenance has waned.
Consequently, under-tightening and over-tightening of packing rings is a prevalent and growing misapplication of centrifugal pump maintenance, with critical consequences to both water consumption and energy draw.
Under-tightening results in too much leakage. Already, when properly adjusted, packing leakage can amount to gallons of liquid leaked per minute. This can be either aqueous solutions comprised of varied benign or caustic chemical compositions, or particles in suspension or slurry, depending on the process.
The heavier the suspension or slurry content in the pumped liquid, the more water is needed to get packing to work reliably. Typically, a clean external flush is piped into the stuffing box through a lantern ring, which keeps the packing lubricated and cool while flushing abrasives and chemicals.
Normally, some portion of the leakage is released continually into the atmosphere. Under-tightening of the packing rings and use of external flushes increase this atmospheric release proportionately, along with environmental impact potential.
- January 02, 2019
Gear motors, pumps and stirring units keep process material in constant motion in the process industry’s production facilities. A large number of shaft seals are used at drive shafts to keep liquids securely within the equipment. But leaks may be more likely to occur if the pressure acting on the seals becomes too great. Freudenberg Sealing Technologies has developed a new rotary seal, the Gerromatic, which has a wave-shaped sealing lip. This increases the maximum amount of pressure that can be applied. The sinusoidal contact path also reduces friction and provides self-cleaning, which extends operating life.
In the process industry, including the food and beverage sector, shaft seals used in equipment mostly have a rotation-symmetrical seal lip, which abuts the rotating shaft with a groove-like contact pattern. During wet-running, this can cause the medium to be displaced at the contact surface. The seal then runs in a more or less dry condition, leading to increased friction and higher temperatures. The increased friction increases wear and reduces the efficiency of the equipment. The accompanying rise in temperature is not desirable, especially when the process media are temperature-sensitive. If the seal lip is also exposed to high temperatures at high rotational speeds – for example, due to a process material that applies pressure to the seal lip in a vessel with a stirring unit below it – the lip can fold down on the low-pressure side, which would result in immediate leakage and the seal’s failure.