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Our People - Experienced Valve Engineers

Onyx Valve Company
835 Industrial Hwy
Cinnaminson, NJ 08077
Ph: 856-829-2888
Fax: 856-829-3080

Our People. Our Strength.

The Onyx Valve Company is only as strong as its people, and our people have the most experience in the industry.  Our people are experienced and helpful and work day in and day out to please our customers and manufacture best flow control products the industry has to offer.  We encourage you to read through our profiles to get to know us.

david gardellin

David Gardellin, P.E., CEO

Co-founder and President of Onyx Valve Company, David is your primary technical resource for the measurement and control of slurries and other hard-to-handle fluids.  He has been involved in valve engineering since starting as Chief Engineer at RKL Controls/Robbins & Myers in 1975.  He holds a BSME from Drexel University and is a registered Professional Engineer in Maryland and New Jersey.  He holds several patents related to pressure measurement and control, and is the author of numerous technical articles including chapters in the ISA Instrument Engineer’s Handbook and the Encyclopedia of Chemical Processing and Design.

Contact David at david@onyxvalve.com

Chuck Witherow, Executive Director of National Sales

Extensive background in Supervison, Project Management, Sales and Trade Shows.
Formal training, schooling and experience in Electronic/Electro/Mechanical as well as customer service support.
Chuck manages and supports Onyx Valve Reps and Customers in many countries around the world.
His professional approach, communication and customer service skills and technical knowledge is a great asset to our company and customers.
Contact Chuck at cwitherow@onyxvalve.com

Chris Schmidbauer, Production Manager/Purchasing Agent/Design Engineer, B.S.M.E.T. Drexel University

Responsible for guiding orders thru the production & purchasing processes, Chris can provide statuses on sales orders & updated shipping dates. He also serves as a rubber part designer as well as the inventory control associate. Excellent communication skills make him an easy person to contact.

Contact Chris S. at cschmidbauer@onyxvalve.com

Howard Leisner

Howard Leisner, Controller

Howard is your first contact for AP, AR, credit approval, credit card transactions, wire transfers, customs issues, and any other financial assistance you may require.

Howard is also our Traffic Manager and can help coordinate trucking, air freight, import and export concerns.

Contact Howard at hleisner@onyxvalve.com

Mark Massimilla, Designer

Co-founder and Lead Designer, Mark is responsible for product design, research & development and the company’s manufacturing database.  He has been involved in valve design since he started as a Designer at RKL Controls/Robbins & Myers in 1984.

Contact Mark at massimilla@onyxvalve.com

Robert Delfino, Draftsman/Designer

Rob is your first contact for certified pressure sensor drawing submittals and approval drawings.  He is also in charge of processing all pressure sensor orders and the design of all specialty pressure sensor projects.

Contact Rob at rdelfino@onyxvalve.com


Robert Schmied, Machine Shop Foreman

Bob is the machine shop foreman, and one of the founders of the Onyx Valve Company. His responsibilities include supervising the daily operation of the machine shop and final parts inspection. Bob was a machinist and shop foreman at RKL Controls/Robbins & Myers, and has over 30 years experience in the pinch valve industry.

Contact Rob at rschmied@onyxvalve.com