Pavement Maintenance Group (PMG) is a leading producer and distributor of pavement sealers, application equipment, and maintenance products for asphalt and concrete surfaces. Its product line includes asphalt emulsion and coal-tar sealers designed for roadways and parking surfaces; and a full suite of tools, equipment, and ancillary products for pavement maintenance.
PMG’s Allentown, Pennsylvania plant mixes, blends and distributes products for the local market. As part of its operation, trucks pneumatically convey silica sand into storage silos.
According to Production Manager Mike Bonner, the Allentown plant’s operating season typically runs from April through November. During those eight months, the facility unloads an average of 12 truckloads of sand per month, each carrying approximately 50,000 lbs./22,680 kg of the highly abrasive material. All of that passes through a pair of sweeps at the top of their silo.
The sand repeatedly eroded the long-radius sweep conveying-line elbows, leading to frequent outages and requiring employees to perform repairs as high as 25 ft. (7 m) above the ground. The Allentown team had attempted unsuccessfully to mitigate these issues using both steel- and concrete-reinforced elbows. In 2020 they approached HammerTek for help.
That year, PMG installed a pair of HammerTek SMART ELBOW® deflection elbows at the top of their silo. Constructed of heat-treated iron, the 90° radius elbows feature a spherical chamber that protrudes partially beyond the normal flow path. This design creates a rotating ball of material suspended in the airstream. Moving in the same direction as the conveying air, the ball cushions incoming material and gently deflects it around the bend, eliminating impact against the elbow wall.
From Chronic Repairs to Long-Term Reliability
Notably, the Allentown plant did not contact HammerTek to order replacement elbows until late 2025, over five years after the original installation. The reason for the contact had nothing to do with the performance of the elbows.
“We have scheduled maintenance timelines for the replacement of pneumatic conveying components,” said Bonner. “Because of those, we needed to replace the elbows, even though they hadn’t required any maintenance for five years. When we dismantled the system and looked inside the elbows, I thought they looked good and probably didn’t need to be replaced.”
According to Bonner, the HammerTek elbows exceeded everyone’s expectations. “When we took the original elbows down, we expected them to be at the end of their service lives” he said. “But they were still in great shape and probably could have stayed on for a few more years.”
“Before we switched to HammerTek we had to do constant repair to the unloading line,” Bonner said. “We no longer lose the production time we used to while we were making repairs.”
