INDUSTRY
Water Infrastructure – Municipal Potable Water
OPERATING CONDITIONS
Size: Up to 84” AWWA C207 Pipe Flanges
Temperature: Ambient
Media: Tap Water
Pressure: 75 psi
Application: Pipe flanges and butterfly valves in potable water distribution
BACKGROUND
An engineering firm designing a large potable water infrastructure project in the Pacific Northwest needed gasketing that could meet NSF 61 certification, seal under low assembly stress, and be fabricated in large, one-piece formats for up to 84” flanges. Ensuring a reliable seal was critical to the timely commissioning of the municipal water system and compliance with public health regulations.
CHALLENGES FACED
The gaskets would face hydrostatic unloading exceeding 415,000 lbs in the largest flanges and had to seal reliably at reduced bolt loads. Butterfly valves in the system presented additional limitations due to low available torque. A previous attempt with alternative materials raised concerns over long-term sealing reliability under these conditions, risking project delays and potential rework.
SOLUTION AND BENEFITS
Garlock recommended MULTI-SWELL® Style 3760 Compressed Fiber Pipe Flange Gaskets, which are NSF 61–certified and available in 120-inch by 120-inch sheets. This sizing allows for one-piece construction even for 84-inch flanges. The gasket’s controlled swell and high compressibility enabled a reliable seal under low stress while maintaining long-term performance under full system pressure.
The customer ultimately selected MULTI-SWELL® for its technical advantages and proven performance in water applications. To address butterfly valve assemblies with limited torque, Garlock also supplied NSF-61 certified Style 98206 EPDM gaskets, optimized for flexibility and performance. The project was completed on schedule with no gasket-related delays, ensuring system integrity and a successful system start-up.
