Being commodity items, U-Cups are readily available in a number of materials and can be found on-the-shelf from multiple distributors and manufacturers in many standard sizes.
Named for the shape of their cross-section, a U-Cup’s design will be pressure energized increasing sealing effectiveness when compared to a standard O-Ring.
This means as pressure increases, the sealing lips are continually forced into the mating hardware surface, ensuring good contact at all times.
The simple and easily moldable design is an effective sealing solution to many systems in both hydraulic and pneumatic applications. Modifications in lip thickness and inclusion of an O-Ring Energizer can tailor sealing loads and wear life to specific situations.
A key advantage to an elastomeric U-Cup is the relatively small and simple hardware space needed. Because of their flexible compounds, most U-Cups can be installed in a solid gland configuration.
A basic ID or OD groove is all you need for proper seal retention. Plus, no special tools or considerations need to be taken for correct installation.
U-Cups are available in many of the same compounds as standard O-Rings such as Nitrile, Fluorocarbon, and EPDM, but polyurethanes may be the most common material.
Urethane provides a good combination of elasticity/pliability and toughness. Therefore, it exhibits good sealing characteristics as well as, durability and wear resistance.
These desirable qualities make U-Cups an optimal solution for many sealing systems across multiple industries and they can be found in countless standard products. But Eclipse is approached many times a year with customers pushing the limits of standard U-Cups and in need of better solutions.
Eclipse was approached by a leading pneumatic cylinder manufacturing seeking a sealing solution for a unique application.
While U-Cups typically provide optimal sealing performance in pneumatic cylinders, this application presented a difficult challenge.
The air cylinder was to be used as an actuator for a latch on a large industrial oven. While pressures, speeds, and cycle times were nothing out of the ordinary, the temperature at which it had to operate at was — a continuous 500°F.
ISO-GARD bearing isolators offer exceptional bearing protection for pumps, motors, and bearing supported industrial equipment under the harshest conditions.
ISO-GARD products are constructed using a filled PTFE material which provides excellent chemical resistance.
Food - Poultry Processing
A diversified food processing company, with facilities located
throughout the US.
The customer had persistent problems with sealing the bearings in their non-metallic feather picker housings. Using standard lip seals, and with a monthly maintenance program, they still encountered frequent failures. With 72 assemblies (each with two sealing locations) this had a detrimental effect on manufacturing efficiency, and placed a significant burden on the maintenance teams.
Poultry feathers were getting under the lip seals and into the bearing housing, causing frequent and unexpected failures. Daily wash-downs also used a chemical cleaning solution that could also damage the bearings if not sealed correctly. Additionally, there was limited space available for any modification of sealing element.
Meat processing environments are highly regulated by the FDA, so any manufacturing changes must be carefully controlled. Therefore the customer required close support to ensure that any changes could be implemented with full confidence.
Metal hose applications can get tricky. Sometimes you can have problems or failures due to the surrounding piping system or because of the way the hose is installed.
Today we are going to discuss Part 2 of the do's and don'ts when it comes to installing metal hose assemblies in a metal piping system.
Hoses can take a great deal of damage when they are torqued. Twisting it stretches the corrugations and the fitting wells and can cause it to fail. To prevent torque, don't install the hose off-center.
When it tries to flex, the assembly will be torqued. Do install the hose in-line with itself; called in-plain. This prevents it from torquing when it flexes, and you should stick to one plain of movement. A quick test for in-plain could be done with either a sheet of paper or a flat surface like a table.
When handling long lengths or coils of hose, it's important to make
A patented lip design and the patented combination of PTFE sealing lip and sliding bearing in the lip seal element provide the new dry running seal "SeccoLip" from EagleBurgmann with particularly high flexibility. These technical features help the lip seal compensate directly and safely radial deflections of the shafts in agitators, mixers and reactors.
The sliding bearing tracks the complete lip seal element to the shaft movements. Since the lip and bearing are in one element, the sealing gap between the rotating shaft and the sealing lip remains virtually constant and the seal remains tight over the long term. Compensating elements such as O-ring, expansion washer or metal bellows are not required for reliable operation.
The modular seal was specifically designed for the operating conditions in the chemical, pharmaceutical, food industry as well
Test-work on Vesconite polymer sliding wear plates have shown promising results on a crawler drill that is employed at a zinc project in the Northern Cape, South Africa.
The wear plates were installed on the rotary head slide of a drill that carries out exploration drilling at the mine from which the goal is to exploit one of the largest zinc orebodies in the world.
The rotary head moves the drill into the ground for deeper and shallower drilling. It also allows the drill to be changed.
Since the rotary head moves approximately 120 times a day, wear on the slides has been considerable, and the original-equipment-manufacturer’s (OEM’s) nylon wear pads were only lasting 500 hours.
As a result, the OEM crawler drill supplier involved in the zinc project sought a solution to extend the life of its wear pads and investigated other wear-resistant materials that could cope with highly-abrasive materials such as chrome and silica that come in contact with
There are over 155,000 public water systems in the United States and more than 286 million Americans who rely on community water systems daily. Since most of the infrastructure was built between the early 1900's and 1960 using outdated technology/products and capabilities, nearly everything is approaching the natural end of it's lifespan.
Some estimates put the repairs and replacement of the infrastructure between $250B and $500B over the next 20-30 years. Several applications will need to be updated or fully replaced for the safety of consumers and quality of delivery, including:
Develop a system that reduces the needle drag and piercing resistance of the septum and injection site materials to increase product performance.
Chemists developed a family of self-lubricated polyisoprene materials that have been manufactured with a proprietary lubricant system and show a minimal reduction of physical and mechanical properties.
By Saman Nanayakkara and Shu Peng
Due to its availability as an ISO 10993 medical grade compound, polyisoprene rubber, which has a unique set of combined mechanical and chemical properties, has been widely used in medical device applications. The material is ideal for septums and injection sites for medical fluid transfer applications. Medical grade polyisoprene compounds have high tear strength and high elastic resilience. These characteristics can provide the desired resealability properties of the septum or injection site after piercing one or more times with a needle.
Medical device manufacturers have long sought a reduction in needle drag or piercing resistance of septum and injection site materials to increase product performance. Post molding surface treatment to modify coefficient of friction is the conventional approach taken to reduce tackiness for improved part handling. This process, however, is a surface treatment for reducing surface friction and does not effectively reduce needle drag, which is caused largely by friction within the septum and injection site materials. Furthermore, this secondary surface treatment adds additional cost to the component.
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Blog.
You’ve probably heard a bit about microwave absorbers and how they are used to reduce or absorb the energy that is present in a microwave. But what are they exactly? And how do they work? Go ahead, read on.
Simply put, microwave absorbers are special materials, often elastomer or rubber based, which are designed to offer a user-friendly approach to the reduction of unwanted electromagnetic radiation from electronic equipment. They also work well to minimize cavity to cavity cross-coupling, and microwave cavity resonances. When comprised of a silicone elastomer matrix with ferrous filler material, microwave absorbers provide RF absorption performance over a broadband frequency range from 500 MHz to 18 GHz.
Stem packing is a familiar product. The most common type is braided compression packing. Braided packing is used in a wide range of applications. Depending on the service, construction materials can be as diverse as plants or animal derivatives, mineral fibers or synthetic plastics and even metal. The process of cutting rings from rope packing, inserting them into a stuffing box and torquing them to the right density is common, but it is not always the best choice.
Another widely used manufacturing method is die-molding. It is the process of wrapping a material around a mandrel, placing it in a die and preforming it to make a seal. Using these and other manufacturing technologies, packing is found to work in applications as different as aerospace, heavy trucking and power generation. A review of some unusual applications demonstrates the versatility of compression packing as a sealing solution.
Compression packing is an ancient technology dating back more than 5,000 years. Boats and ships used a rudder as a steering mechanism. The rudder shaft penetrates the hull of the vessel below the water line, so water can leak into the bilge. Ancient sailors, using the top technology of the day, would take pieces of clothing, sail cloth and rope, cover it with animal fat or wax and stuff it into the gap around the shaft. Eventually, a box was secured around the shaft and a gland, which could be tightened to compress the packing material, was created to improve sealing and longevity. The terms compression packing, stuffing box and gland come from these early sailors.
Over time, many improvements in packing construction and materials were made. Packing today can be made of flax, Kevlar, polytetrafluoroethylene (PTFE), graphite or metal. It typically has a square cross-section and is sold in precut rings or in large coils, as shown in Image 1. Synthetic aramid fibers are abrasionresistant and can handle higher temperatures and shaft speeds. PTFE has excellent lubricity and chemical resistance. Graphite coupled with mica or an aramid fiber can stave off the heat generated by a rotating shaft and provide long life in challenging applications.
Die-formed compression packings are excellent in terms of sealing performance and reliability and offer a wide range of long-term, low-emission and low maintenance products. See Image 2.
Not only are die formed rings easier and quicker to install, but the pre-compression increases the density of each ring and reduces the gland loads necessary to seat and compress multiple rings in the stuffing box. The result is lower friction on the shaft or the spindle, with improved sealing performance and a longer life.
As mentioned in an article previously published by the Fluid Sealing Association, (Sealing Sense, Pumps & Systems, March 2005), there are several key factors to consider when choosing the right packing. They include:
Keeping this in mind, here are some applications to consider when you are going way beyond the typical stuffing box: