Archive for May, 2011
Simrit’s Exceeding Limits, Part 2: Pressure |
May 1131 |
Increasingly high system pressures in units have to be safely contained. For this, Simrit not only offers high performance materials. Its innovative designs also set new benchmarks, for example in the area of pressure relief, and reveal savings potentials. Below is part two in the four part Exceeding Limits series.
Pressure balance made easy
Covers are there to close openings and necessary in industrial engines. Creativity begins where additional tasks—such as pressure balancing—are to be performed in addition to the mere closing function. This has led to sealing innovations such as Simrit’s Gas Permeable Cover Seal which provide engines manufacturers with considerable savings potentials during production and assembly. Drill holes in machines or in industrial engines are usually covered and sealed with low-cost covers. When the engines (and the lubricants contained) warm during operation, pressure can increase by up to 0.5 bar. This puts considerable strain on shaft seals due to the long-term pressurization, causing higher wear and reduced service life. Increases in pressure can in severe cases cause seals and covers to be pushed out of their installation spaces. This problem has been dealt with in the past by installing air bleed valves. This required considerable additional effort: additional holes had to be drilled, threads had to be tapped and a valve had to be purchased, stored and assembled. All of this will no longer be necessary.
Covers with additional functions
The integration of a breathing function directly into the cover allows Simrit to create savings potentials for engines with high thermal loads. In order to achieve this automatic pressure balancing, very small holes are made in the standard covers. These micro-openings are sealed with a specially treated nonwoven material. This new nonwoven material allows air to permeate but is impermeable to water and oil due to the special treatment which it has undergone. The nonwoven material ensures pressure balancing and prevents both ingress of water as well as any leakage of oil and lubricant, thanks to its hydrophobic and oleophobic characteristics. This allows all types of engines to run with greatly varying temperature fluctuations—ranging from sub-zero temperatures to approximately 120°C (even with short peaks of 150°C)—without any major pressure fluctuations.
Principle can be transferred to other components
The newly developed Gas Permeable Cover Seal with pressure balancing is a strong example of how the functionality of products can be expanded by thinking beyond seemingly unsurpassable limits. The reduction of components—in this case of the additional valve—not only improves reliability and service life of the seal, it also lowers costs. And that is not all: the idea sets a precedent and it is expected that this innovative technical application of pressure balancing will be used in other machine components such as bellows and Simmerrings.
For more information visit: www.simrit.com/exceeding-limits/pressure.
Simrit Debuts Expanded Portfolio of Ventoguard™ NBR Materials at WINDPOWER 2011 |
May 1123 |
To meet the extreme demands of the evolving windpower industry, Simrit will debut its expanded line of nitrile butadiene rubber (NBR) sealing materials during the WINDPOWER 2011 show in Anaheim, Calif. from May 22 to 25 (booth #1529). Simrit’s two new NBR developments are part of its Ventoguard™ line of materials specifically designed to offer superior grease and ozone resistance, low compression set and low-temperature capability.
“The windpower industry is growing and evolving at a rapid pace,” said Reddy Tudi, sales director, renewable energy, Simrit. “To meet the unique needs of this developing industry, Simrit engineers are continually driving the development of materials and seals that will extend the performance of windpower applications.”
Ventoguard 453 and Ventoguard 454 are the next-generation of Simrit’s well-established line of proven NBR materials. Primarily used in slewing bearing profile seals in wind turbines, both materials were developed for long-term reliability and superior resistance to environmental and chemical concerns.
Additionally, each material was designed to address a specific windpower-related challenge with the ultimate goal of helping prolong the maintenance cycle of the sealing application. Ventoguard 453 is a premium material that offers excellent cold flexibility, very good compression set and demonstrates superior aging in several greases, including Kluber, Fuchs and Mobil. Simrit’s Ventoguard 454, also a new premium material, provides superior compression set and is optimized for use in Shell Rhodina BBZ greases.
For additional information or to speak with a Simrit expert about the company’s NBR material innovations, stop by the Simrit booth (#1529) during WINDPOWER 2011 held at the Anaheim Convention Center in California from May 22 to 25 or visit www.simrit.com.
Simrit is part of the group Freudenberg-NOK Sealing Technologies, which has total annual sales of more than $7 billion. The global Freudenberg and NOK companies offer an extensive portfolio of precision-manufactured products for the aerospace, agriculture, appliance, construction, energy, fluid power, mechanical power generation, mechanical power transmission and recreational markets. For more information, visit the Simrit website at www.simrit.com.
# # #
Editor’s Note: For a high-res image of Simrit’s NBR material innovations, please contact Adriana Ferrari at 248-269-1122 or aferrari@bianchipr.com.
Simrit’s Exceeding Limits, Part 1: Temperature |
May 1119 |
Seals affect functionality, quality and safety of the entire unit. Increasing demands on performance levels of the various units result in increasing demands on the seals and sealing manufacturers have to react accordingly. However, technology leaders such as Simrit, go one step further: they act rather than react, and build today’s seals so they will also fulfill tomorrow’s demands from manufacturers. At the Hannover Fair, Simrit presented the results of its innovation potential in the areas of pressure, movement, temperature and media. Below is part one in the four part Exceeding Limits series.
The quality of a material is revealed at the top and bottom end of the temperature scale. Simrit’s new, high performance materials allow exceptional functionality, even under extreme temperatures.
Staying cool even at 180°C
Seals in crankcases have to withstand high air and cooling water temperatures and require resistance to non-polar media such as oil. This presents a near impossible challenge for elastomer materials. But Simrit offers a solution in the form of materials Coolant FKM (FKM 233877) which provides a quantum leap for seals in big drive units. Inside big engines, such as diesel engines on ships, temperatures run high. So high that even the cooling water reaches temperatures above 150°C. High demands are placed on, O-rings which seal cooling water against engine oil in diesel engine cylinders. They not only have to be highly oil-resistant, they also have to withstand long-term exposure to cooling water temperatures above 150°C without showing signs of wear.
Resistant to oil and cooling water
Until recently, FKM 606 was known to be the best material (specifically for wet cylinder liners) due to a temperature resistance to > 230°C in air and furthermore resistance to oil and cooling water. However, the cooling water must not get any hotter than 150°C, as it can otherwise lead to erosion at the crank case in which the cylinder liners are inserted.
Coolant FKM achieves the seemingly impossible
With elastomer materials it is difficult to achieve good resistance to polar materials, such as water, and at the same time to non-polar materials, such as oil or grease. Simrit’s newly developed material Coolant FKM represents a real quantum leap. Its resistance to cooling water reaches up to 180C and the materials show also good resistance to high temperatures and oil. The long-term compression set in cooling water of 180°C (water/glysantin) is excellent and has been successfully tested against a competitor material in a test period lasting 1,000 hours. The high temperature resistance of this new material is high and comparable to that of FKM 606. Even short peaks of thermal strain reaching 250°C do not destroy the seal or cause it to fail. Coolant FKM is, in addition to that, highly suitable for increasingly popular engine oils with additives and can be used on a larger scale. The main advantage of this material, however, is its much higher resistance to cooling water. Coolant FKM noticeably improves the previous limits and can be used in cooling water of temperatures up to 180°C. It is a good example of a Simrit innovation that is one step ahead.
For more information visit: www.simrit.com/exceeding-limits/temperature.