Page 350 - Facility Piping Systems Handbook for Industrial, Commercial, and Healthcare Facilities

SITE UTILITY SYSTEMS

6.72 CHAPTER SIX

Cleaning Ball
The cleaning ball method is limited to light cleaning of sewer pipe, for example, new piping
recently installed or pipe in which almost no accumulation of debris is present. This method
uses a ball with serrated ridges around its circumference, which is slightly smaller than the
pipe to be cleaned. The ball is placed in the pipe and water is added behind the ball. The water
pushes forward and forces its way through the serrations. The water pressure on the ball
causes the ball to rotate and dislodge any light dirt. The water forcing its way around the
ball flushes the loosened debris away.

Hydraulic Jet Rodder
Application of the hydraulic jet rodder (HJR) is limited to pipes filled to no greater than
30 percent of their depth with dirt or debris. This method uses a bullet-shaped head, with
water nozzles both in front and in the rear, attached to a flexible hose. The head is inserted
into a sewer through a manhole and uses the water jet to force its way into the pipe. This
action drives some debris in front of it, but also leaves much debris at its rear, behind the
head. The head is then withdrawn back to the manhole where it was inserted, using the rear-
facing water jets to force the loosened dirt and debris to a point where they can be easily
removed from the manhole. Depending on the particular machine used, water pressure up
to 4000 psi can be developed. Care must be exercised to avoid damage to the pipe, which
is a limiting factor to the amount of debris which can be loosened. In addition, a circular
rotating blade, operated hydraulically, can be attached to the head for cleaning grease, with
the rear-facing jets of water removing it back to the manhole. It is anticipated that the jet
rodder will become the most popular method of pipe cleaning.

Bucket Machine

Application of the bucket machine is limited to piping filled to between 30 and 99 percent
with debris. An open bucket capable of remote closing and attached to a cable is inserted into
the sewer pipe from one manhole with its open end into the pipe. The cable must be pulled
from two ends, usually from one manhole to another. The cable, with bucket attached, is
pulled forward into the sewer. When filled with debris, the bucket end closes and the other
end of the cable pulls the bucket backward to the manhole, where it is emptied. This process
is repeated until the line is clear. If a sewer line is completely blocked, preventing a cable from
being stretched from one point to another, this cleaning method cannot be used.

Excavation and Disassembly
When a pipe is completely blocked, and standing water is observed in the manhole, there may be
no other alternative than to excavate around the pipe at a joint, disassemble the joint, and remove
the accumulated debris from a trench by hand. This method also requires a portable pump.

Manhole or Drainage Inlet Cleaning
This is accomplished with a “clam digger,” a small-diameter, articulated finger-type machine
that can reach down into a manhole or inlet for debris removal.

Vapor Rooting
Vapor rooting is used only to chemically remove roots inside a sewer and retard their future
growth outside the sewer for several years. Its application is limited to sewers that rarely

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