Cities and sewerage agencies often collect wastewater from large areas that must be conveyed to distant treatment plants. Handling this enormous volume requires large-diameter trunk lines. It is not unusual to find trunk lines more than 100 inches in diameter. Because these lines carry such large flows, they often run well above the half-pipe and at more than 10 feet per second. This often prevents the use of standard camera crawlers for CCTV inspection.Most inspection equipment manufacturers offer crawlers designed for large-diameter pipes. As water level increases, these crawlers have remote-controlled elevators, or scissor lifts, that raise the camera 1
