Contractor uses pneumatic pipe plugs to meet extremely high head pressures

Problem: 

As part of a project that lasted a year and a half, The Metropolitan Water Reclamation District of Greater Chicago performed structure rehabilitation and pipelining along 175th Street and Ridgeland Avenue in the Chicago suburb of Tinley Park. The project’s objective was to update the infrastructure and prevent further deterioration of existing pipes and structures. Instead of digging up and replacing the old line, Insituform Technologies inserted a cured-in-place lining inside 14,051 feet of 60-inch sewer pipe. A Tinley Park-based subcontractor, Airy’s, supported the installation of the cured-in-place lining. Airy’s role as the subcontractor was to plug the sewer lines and bypass the entire 14,000 feet of sewer line, so Insituform Technologies could get into the line and safely put the cured-in-place liner in the pipe.

Solution: 

Airy’s used large bypass pipe plugs manufactured by Cherne Industries to stop and redirect wastewater flow into the bypass system. The subcontractor used Muni-Ball pipe plugs to meet extremely high head pressures and safely plug the lines, bypassing 14,000 feet of 60-inch sewer line. 

Result: 

With the use of pneumatic pipe plugs, the contractors did not have to enter the sewer to plug the pipe. For ultimate safety, Airy’s “double-plugged” the sewer, says Airy’s project manager Tom Land. The plug performance proved excellent, even in extreme rain events that truly tested the durability of the plugs. “These plugs had extremely large flows through them and were able to meet extremely high head pressures,” says Land. 800-843-7584; www.cherneind.com 

Large liners a fit for CIPP rehab of corrugated metal pipes

Problem: 

Large, deteriorating 72-inch corrugated metal pipes in Santa Rosa County, Florida, were full of water from three weeks of rain, delaying a relining project. Originally PCC had planned to transfer the large liners needed from FerraTex’s rental trailer into their own 53-foot refrigerator trailer, but their Cat 938 loader could not handle the 72-inch liners, each weighing in at 15,000 pounds.  

Solution: 

PCC took over the rental from FerraTex Solutions. “Because FerraTex did such a great job icing, the liners were saved, no issues whatsoever, in the summer, in Florida, for three weeks” says Ben Joyner, president of PCC. With the three 72-inch-diameter pipes being side by side, the excess water was diverted to flow through one pipe while the others were isolated to fit large scaffolding in front of the host pipes for installation. PCC used five 6-inch pumps to divert from the upstream side of the road through the discharge pipe, which ran into the woods. An additional 6-inch pump on the downstream side helped divert water away. Once the uphill battle against water diversion, rainstorms and high tide was won, installation began.

Result: 

A large excavator was brought in to lift each 15,000-pound liner 10 feet to the top of the scaffolding. Water curing was chosen, and the install was completely successful. 844-433-7728; www.ferratex.com 

Severe leak stopped with trenchless point repair

Problem: 

Peachtree City (Georgia) Water and Sewerage Authority (PCWASA) was experiencing a major leak in an 8-inch ductile iron sewer line under a high school football field. Infiltration was estimated at 50 gpm on dry days and rain events increased the infiltration significantly. The leak resembled a hose outlet open in the side of the line. Traditional dig-and-replace repair methods with dewatering would have been extremely expensive.

Solution: 

A PCWASA crew installed an 8-inch by 3-foot trenchless point repair, manufactured by Infrastructure Repair Systems. The repair was accomplished in a single day from above the manholes: no trenching, dewatering or excavation required. Not even bypassing of the sewer line was required. The city’s installation of the Trenchless Point Repair Kit sealed a major source of infiltration.

Result: 

By utilizing the kit, the utility repaired a significant leak for a fraction of the cost of traditional methods. They also realized a large reduction in pump run time at the downstream lift station — from 50 down to 30 gpm. Calculations from actual pump runtime showed minimum reduction of 15,768,000 gallons per year and a cost savings of $24,236 annually. The utility saved more than the entire cost of purchasing the system, inclusive of kits and equipment with their very first repair. 

727-327-4216; www.irsi.net

Couplings used to connect deeply buried fire hydrants

Problem: 

The Town of Gilbert, Arizona, has most of its fire hydrant piping 3.5 feet underground, except for older fire hydrants that have been buried closer to 6 feet. When the infrastructure for these older hydrants deteriorated, they needed to be replaced, but the repairs presented safety issues given the depth of the pipe. Each time crews needed to reconnect a fire hydrant to the mainline, shoring needed to be put in place to help prevent cave-ins. In addition, under digging was needed to allow space for tightening the bolts given the small space. The utility was looking for a way to minimize the time in the ditch and have the job done quickly.

Solution: 

The utility chose the HYMAX Grip from Mueller Water Products, which has only two bolts to tighten compared to six on traditional mechanical joint restraints. Reducing the number of bolts to tighten makes a huge difference in getting the job done quickly. The space needed to repair fire hydrants is relatively tight, so anything that can make the job easier is a plus. Also, if you don’t have to dig underneath to reach bolts close to the ground, it means that the ditch is more stable with a lower chance of cave-ins.

Result: 

A quick and easy installation meant minimal time in the trench, making it safer for crews and allowing them to move on to the next project. 855-457-2879; www.muellerwaterproducts.com

Epoxy used for rehabilitation of large-diameter pipes

Problem: 

A 370-foot-long 87- by 136-inch elliptical pipe and 541-foot-long 96-inch-diameter pipe both had severe crown corrosion at San Jose Water Treatment Plant. An assessment estimated the remaining service life range of the pipes between 0 and 12 years. A high priority was given to performing a structural lining on these pipes.

Solution: 

Michels Pipeline recommended using geopolymer for repairing badly deteriorated spots, followed by coating the pipes with Neopoxy high-strength corrosion-resistant NPR-5304 epoxy resin. The project owner decided to line only the top half of the pipes due to the more serious corrosion in that area. The Michels crew applied epoxy using plural component spray equipment at 125 to 150 mil thickness.

Result: 

The project was completed successfully. The coating successfully passed the spark and adhesion tests, and the pipes were back in service within a few days. Through the application of the epoxy, the lifespan of the large-diameter pipes was extended by approximately 50 years. 510-782-1290; www.neopoxy.com