Polyurethane seal from Freudenberg-NOK Sealing Technologies replaces PTFE seals in hydraulic piston accumulators

  Polyurethane seal from Freudenberg-NOK Sealing Technologies replaces PTFE
                    seals in hydraulic piston accumulators

SIMKO 300 seal ring proves impressive in wind power facilities

PR Newswire

PLYMOUTH, Mich., Feb. 7, 2014

PLYMOUTH, Mich., Feb. 7, 2014 /PRNewswire/ --Hydratech Industries, a leading
provider of solutions for wind power facilities and hydraulic systems, is
relying on a polyurethane sealing solution from Freudenberg-NOK Sealing
Technologies for its new hydraulic accumulator. Test comparisons with other
products have shown that Freudenberg-NOK's SIMKO 300 seal ring offers distinct
advantages over frequently used polytetrafluorethylene (PTFE) seals with
regard to operating life, form stability and sealing characteristics.

The durability of sealing rings in piston accumulators is a crucial parameter
for operating life. For this reason, piston accumulators undergo accelerated
load tests at the Hydratech test center in Sikeborg, Denmark that simulate 20
years of service life. During the testing process, the behavior of the seals
under pressures greater than 200 bar and temperatures ranging between -104
degreesto +140 degreesF is measured – conditions that exceed actual

Based on its form stability, extreme hardness and low abrasion, Hydratech now
usesthe SIMKO 300 from Freudenberg-NOK. The sealing solution "fully meets our
expectations and is impressive due to its long service life," said Jimmi
Wenderby, Hydratech research and development manager.

Most sealing systems in piston accumulators work with two seals, one for oil
and another for gas. This leads to increased wear due to the extreme load,
especially in PTFE seals. By contrast, the SIMKO 300 is a single seal
(consisting of a seal ring and a pressure ring) and is made of polyurethane.
Polyurethane's hardness grade of 98 Shore A corresponds to that of PTFE but is
much more robust. Its susceptibility to potential surface damage during
installation is also lower. The pressure ring creating the necessary
pre-tension is made of an elastomer.

The SIMKO 300 seal's high form stability, its surface firmness and its long
operating life make it especially appealing for use in hydraulic pitch
controllers in wind power facilities. They are an important component of the
security technology in wind power facilities, as the piston accumulator must
not merely function reliably under extreme weather conditions but also
withstand the high differential pressures that are also produced. The
accumulator must be able to operate leak-free over very long periods of time.

The SIMKO 300 is a cost-effective and extremely reliable solution for use in
piston accumulators, and it provides a long service life for the wind power
station due to its outstanding sealing qualities.

About Freudenberg-NOK Sealing Technologies

Freudenberg-NOK Sealing Technologies is the Americas joint venture between
Freudenberg and Co. in Germany and NOK Corp. in Japan. Freudenberg-NOK is a
leading producer – through its Automotive, Merkel, Process Seals and Simrit
sales channels – of advanced sealing technologies for a variety of markets
including: aerospace;agriculture; appliance; automotive; construction; diesel
engine; energy; food and beverage; heavy industry; and pharmaceutical.

Founded in 1989 under the legal name Freudenberg-NOK General Partnership,
Freudenberg-NOK is headquartered in Plymouth, Mich. and operates more than 20
facilities across the Americas. For additional information, please visit

SOURCE Freudenberg-NOK Sealing Technologies

Website: http://www.fnst.com
Contact: Cheryl Eberwein, Director, Media Relations, Office: +1 734 354 7373,
E-Mail: cheryl.eberwein@fnst.com; Leslie Dagg, Bianchi PR, Office: +1 248 269
1122, E-Mail: ldagg@bianchipr.com
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