Velcon Filters, LLC, a Portfolio Company of The Sterling Group, Completes Acquisition of Twin Filters B.V.

COLORADO SPRINGS, Colorado, March 31, 2011 - Velcon Filters, LLC, a manufacturer of industrial filtration systems,
today announced that it has acquired Twin Filters B.V. Velcon is a portfolio
company of The Sterling Group and was acquired in 2009 as a platform to
execute a buy-and-build strategy.

With headquarters in The Netherlands, Twin designs, engineers and
manufactures filtration equipment and replacement cartridges for the oil,
liquid and air filtration markets in Europe, Asia, North America and other
international markets. Wijbrand Schouten, the founding CEO who will remain
with Twin in his current role, commented, "Velcon is the clear leader in the
jet fuel market, and we are pleased to combine our organizations to continue
to deliver top quality products and solutions to our collective customer
bases globally."

Velcon manufactures filtration systems, including vessels and replacement
cartridges, which meet specific requirements for fluid filtration processes
in a variety of domestic and international end-markets, primarily the jet
fuel market. Dave Taylor, President and CEO of Velcon, said, "Since 1985,
Twin has provided the highest quality filtration devices for the oil, liquid
and air filtration markets. We are pleased to partner with Wijbrand and his
team at Twin and to provide a broader range of products and solutions to our
customers."

The acquisition of Twin represents an expansion into new end-markets and
geographies. "Velcon acquired Chemflo in late 2009 to expand our product
offering into the downstream energy markets, and now Twin provides
significant growth opportunities in the upstream markets," Greg Elliott,
Partner of The Sterling Group said. "We are excited to capitalize on the
synergies that Velcon and Twin's collaboration will provide." The acquisition
was financed with equity from Sterling Group Partners II, L.P. and debt
financing from BNP Paribas, Amegy Bank of Texas and D.E. Shaw.

About Velcon Filters, LLC

Velcon, headquartered in Colorado Springs, CO, manufactures housing
vessels and replacement cartridges used in the filtration of industrial
fluids. The company is a global leader in the filtration process for jet fuel
delivery, manufacturing products that filter, purify and remove water from
jet fuel. End users of Velcon's products primarily include airports,
contracted fuel providers, FBO operators, militaries and pipeline operators.
Velcon Process manufactures filtration products for commercial and industrial
diesel consumers, refineries, petrochemical facilities and utilities.

About The Sterling Group, L.P.

Founded in 1982, The Sterling Group is a private equity investment firm
that targets controlling interests in basic manufacturing, distribution and
industrial services companies. Typical enterprise values of these companies
range from $100 million to $500 million. Sterling has sponsored the buyout of
39 platform companies and numerous add-on acquisitions for a total
transaction value of approximately $9.0 billion. Currently, Sterling has $1.3
billion of committed capital under management through three funds. Current
portfolio companies include North American Energy Partners, CST Industries,
Roofing Supply Group, Universal Fiber Systems, Velcon Filters, Express, B&G
Crane Services and Saxco International.

Franny McKay, +1-713-341-5756, fmckay at sterling-group.com