835 Industrial Hwy | Cinnaminson, NJ 08077



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, 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, Vice President of 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

Khizar Shaikh, Sales Engineer

Khizar is a Mechanical Engineering graduate from Rowan University and a local to the greater-Philadelphia area. He excels in providing engineering solutions and is a great contact person for technical support and quotations.

Contact Khizar at kshaikh@onyxvalve.com

Jeremy Christiansen, Application Engineer

Jeremy is a Mechanical Engineering graduate from Rutgers University with a passion for delivering engineering solutions. Known for his great customer support, Jeremy is eager to explore new processes and customer projects. Count on him as your contact for both technical support and quotations.

Contact Jeremy at jchristiansen@onyxvalve.com

Meredith Foster, Expediting and Traffic

Contact Meredith to check order status and for help arranging shipments to or from Onyx Valve Co including ground freight and expedited freight options.

Contact Meredith at mfoster@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

Katherine Gifford, Accounting

Katherine is your first contact for AP, AR and credit card transactions.

Contact Katherine at accounting@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


Dave Headley, Assembly Foreman and Co-founder

Dave has over 30 years’ experience building pinch valves. He has assembled, installed and repaired valves with pneumatic, electric and hydraulic actuators and positioners, and has assembled, calibrated and repaired pressure gauges, switches and transmitters.



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