MAS Butterfly NSF

M.A. Stewart & Sons Ltd., is pleased to announce the recent certification of the MAS D-Series (Ductile Iron Body) and S-SERIES (Stainless Steel Body) Butterfly Valves to NSF-61, covering safe drinking water requirements.

The NSF-61 certification is in addition the existing NSF-372 certification for lead free applications and will allow for a broader marketing and application base for the MAS Brand. The extensive third party certification (attached) was performed by Truesdail Laboratories and is accredited by ANSI Certificate #0303, with certification carrying through 2021.

Testing for NSF-61 goes well beyond the testing requirements and certification requirements of the NSF-372 standard that was solely intended for the measurement of the weighted average of lead content and ensuring it meets the required .25% maximum lead level.

NSF-61 considers the limits and measurements of over 150 additional toxicities and elements that carry potential migration/contamination concerns when coming into contact with materials in potable water applications.

The NSF-61 certification includes all MAS D & S Series Butterfly Valves with seat configurations of EPDM, Food Grade EPDM, NBR, Natural Rubber, EPDM Lined PTFE & Silicone and with Disc materials of Aluminum Bronze, Stainless Steel, Nylon 11 Coated Iron or Teflon Coated Stainless Steel.

All new shipments from the factory will be received with the NSF markings. As this certifications was achieved with using the existing design and models (a testament to the quality and design of the MAS Brand), the certification is backdated and is applicable to on hand inventory.

We would also like to advise that the MAS Butterfly Valve Series have been granted American Bureau of Shipping / ABS and US Coast Guard Approval Status and these certificates will be forthcoming.

If you have any questions, please do not hesitate to contact your local M.A. Stewart & Sons representative or

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June 24, 2016 CertificationMASNSF