Jason McIlwee, PE is the Utilities Engineering Manager for the Department of Utilities in Charlottesville, Virginia. The city has a population of about 48,000 with 15,000 customers served by 183 miles of piping. The pipe sizes range from 2” to 18” which are made from a range of materials including galvanized iron, ductile iron, cast iron and high-density polyethylene.
The utility was going to replace a mechanical Tee that had 2” piping connected to it. To address customer complaints related to low water volume and water discoloration, the utility was going to replace the pipes with 6” piping. A new Tee needed to be installed and the utility was looking for a fast, easy way to make the replacement while minimizing water shutdown time.
The Charlottesville utility had used HYMAX® products for the last 13 years, including the HYMAX GRIP® products over the last six years. The HYMAX GRIP Tee was easier and faster to install compared to the mechanical joint Tee – each end of the T only had one bolt to tighten compared to multiple bolts. McIlwee and his crew were able to replace the 2” piping with the 6” and insert the HYMAXGRIP Tee T in about an hour compared to several hours with the mechanical Tee. Both pedestrian and road traffic were minimized, and customers could return to regular water service with reduced disruption.
There were three advantages for using the HYMAX GRIP® Tee:
1. Ease of Installation
The HYMAX GRIP® chain provided a circular restraint around the pipe, unlike typical wedge-style restraints that point-load and weaken the pipe. As the pipe applies axial pressure, the HYMAX GRIP chain tightens around the pipe to prevent pullout. The radial closing mechanism also held the pipes tightly in place during installation to give installers full control over the gap between pipes.
The universal gripping system restrains metal and plastic pipes and has a transition capability of up to 1.1”. It can work with a wide range of pipe diameters, meaning that Charlottesville’s water utility had extra flexibility to use the HYMAX GRIP Tee for a variety of other pipe sizes. By using HYMAX GRIP Tee instead of mechanical joints, the utility could get the job done faster and spend less time in the ditch. “Anytime we can minimize worker time in the ditch is a good thing as it makes for a safer work environment,” said McIIwee. “With fewer bolts to tighten, we could install the Tee faster, get workers out of the ditch and return water service to customers in less time.”
2. Durability and Flexibility
The HYMAX GRIP Tee is made of durable ductile iron and can withstand a working temperature of up to +125°F. It meets or exceeds standards AWWA C219, NSF-61 and NSF-372.
The coupling’s dynamic deflection reduced the risk of damage and cracking due to ground shifts. The HYMAX GRIP Tee’s patented gasket effectively transforms the pipe joint into a flexible connection and allows dynamic deflection of up to 4 degrees per side. It can also adapt to out-of-round pipe shape (up to 0.16”) for optimum fit on both ends with its radial closing design and sealing system that can eliminate installation errors. Even if pipes are just a bit out of alignment, the GRIP’s dynamic deflection can still allow for the connection.
3. Advanced Anti-galling
The HYMAX GRIP Tee’s nuts and bolts have advanced anti-galling using a unique dry treatment process with Molecular Anti-Galling (MAG) based on embedded zinc to prevent galling and enable repeated bolt tightening. It also eliminates the need for grease, preventing dust and dirt build-up. The HYMAX GRIP Tee’s fusion-bonded epoxy coating also helps insulate against corrosion.
Editor's Note: Scranton Gillette Communications and the SGC Water Group are not liable for the accuracy, efficacy and validity of the claims made in this piece. The views expressed in this content do not reflect the position of the editorial teams of Water & Wastes Digest, Water Quality Products and Storm Water Solutions.
