The Critical Role of Pipe Jointing in Large-Diameter Sanitary Sewer Systems

Proper pipe jointing is a critical aspect of designing and installing sanitary sewer systems – especially in the sizeable diameters of 30” and larger. The large joints of these systems play a pivotal role in preventing issues related to infiltration and exfiltration, which can have detrimental effects on the overall functionality of the infrastructure. Inflow and infiltration (I&I) during rain events can lead to capacity issues at wastewater treatment plants, causing severe backups in the system and sanitary sewer overflows (SSOs). This excess flow creates additional costs for treatment, environmental cleanup, and may also expose municipalities to expensive fines by Federal regulators.

As a result, understanding the importance of reliable joints is essential for the long-term performance of large-diameter sanitary sewer systems.

One of the primary standards for evaluating the reliability and performance of joints in gravity sanitary sewers is ASTM D-3212. This specification, established in 1973, sets the criteria for testing the joints by subjecting them to internal pressure of 10.8psi and evaluating their ability to hold this pressure for 10 minutes with no leakage. The joints are laboratory tested with a straight pipe configuration and a vertical ring deflection of 5% to ensure their effectiveness.



Moreover, as the focus on expanding U.S. infrastructure grows, the demand for larger diameter pipe systems is increasing. Materials such as reinforced concrete pipe, fiberglass pipe, and steel reinforced polyethylene (SRPE) are commonly used for large-diameter sewer projects. For gravity conveyance, these materials require joints that comply with ASTM D-3212, ensuring their ability to withstand the hydraulic and structural demands of the system.

Contech’s DuroMaxx® SRPE, in particular, has emerged as a growing large diameter pipe material due to its resistance to corrosive chemicals (including hydrogen sulfide gas), superior abrasion resistance, and most importantly - joints which are fully reinforced with high-yield steel. An added benefit of this large diameter double gasketed joint (called QuikJoint®) is that it provides the ability to perform a safe post construction air test at each joint, as opposed to other costly and time-consuming measures.

In conclusion, the significance of pipe jointing cannot be overstated in the context of large-diameter sewer systems. Adhering to standards such as ASTM D-3212 and selecting appropriate materials with reliable joints is essential for ensuring the long-term functionality and integrity of these vital infrastructure components. For more information or to see how Contech might assist on your next large-diameter sanitary sewer project, please visit