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

Mahbubul Shawrav, Sales Engineer

Mahbubul Shawrav (Shaw) is a Mechanical Engineering graduate of Rutgers University, and the newest member of the Onyx Valve family. His background in engineering and IT customer support makes him an ideal candidate to learn and grow as a sales engineer. He is a great contact person for quotes and customer support. His goal in the future is to pursue a master’s degree and possibly beat his predecessor in meeting Dolly Parton.

Contact Shaw at shaw@onyxvalve.com

Chris Reidl, Sales Engineer 

Graduated from Drexel University with a degree in Engineering Technology.  Chris fields quote requests and provides tech support.  Chris has developed numerous spreadsheets and word documents to streamline quoting and engineering in a consistent accurate process.  Building on experience in the restaurant industry, multitasking is one of his strengths.  An animal lover, Chris lives with two black cats, one fish tank and his fiancé in Yardville, NJ.  Chris is the primary contact for Spanish-speaking customers.

Contact Chris at creidl@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


Taylor Mahon, Purchasing Agent

Taylor Mahon is your key contact for Outside Purchasing at Onyx Valve Co. With years of experience in customer service and sales, Taylor is quick to purchase instrumentation and raw materials necessary to complete orders, verify their specification and schedule incoming deliveries, organize any and all documentation, and compare receipts to ensure correct and on-time delivery for final products. If you’re an Onyx supplier, Taylor can clarify any unclear items to make certain we’re getting what’s best for the customer.

Contact Taylor at tmahon@onyxvalve.com

Chris Schmidbauer, Engineer, B.S.M.E.

Chris Schmidbauer is responsible for valve design. He is also your contact person for submittal packages and any other documentation related to pinch valves and duckbill valves.

Contact Chris S. at cschmidbauer@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 Foster, 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


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


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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