by Thomas Westerkamp
New technology to assess and
address drain and pipe problems
puts additional power in the hands
of front-line technicians
Today’s drain cleaning systems are a far cry from the
rudimentary systems employed by maintenance
departments in years past to keep plumbing systems
operating and pipes flowing smoothly. These advanced
systems feature improvements in materials, designs and
technology that enable managers to put greater power in
the hands of front-line plumbers and equipment
technicians, which can enable them to diagnose plumbing
system problems more quickly and accurately.
The options available to today’s technicians for assessing
pipeline problems generally fall into two categories —
mechanical and chemical.
Equipment options
Sectional cable machines. These units can be
electric or gas driven and can clean lines up to 300
feet. They are available for application in 1-1/4 to
10-inch diameter pipe and in increments of 1-1/4
inches to 4 inches, 2 – 8 inches, 2 – 10 inches, etc. Speeds of
600-700 rpm enable them to remove buildup and cut roots that
invade underground drains.
Drum-type cable machines. These units have quick-disconnect
drums and quick- connect couplers for faster setup
and easier transport through narrow passages. They also are
designed for problems with sink and floor drains, and they
offer line diameters ranging from 1-1/4 inches to 10 inches,
cable lengths of up to 250 feet, and in- and out-feed rates of
more than 20 feet per minute.
Rodders. For heavy-duty, large diameter pipe, rodders with
an attached gas engine can handle up to 500 feet of line length
with sectional rod and up to 24 inch-diameter pipe.
Water-jet machines. Water jet machines are driven by either
electric or gas engines. Typical electric units handle more than
200 feet of 1-1/4 – 4 inch drain. Connected to a water source,
they deliver high-velocity pulses of water forward and
backward at 1,250 pounds of thrust to remove sludge buildup.
Gas units remove soap, grease and sludge in 1-1/4 inch to 6
inch drain lines. A 5-1/2 hp drive delivers pressure at 2,100
psi, which is controlled by a foot valve. Both electric and gas
units can be hand-carried or two-wheel-cart-mounted with
hose.
With up-to-date drain inspection equipment, smart managers
can mitigate risks by viewing the condition of a drainage
system at periodic intervals, documenting impending
problems, and recording the findings using both audio and
video of the actual interior condition of the lines to backup
recommendations for corrective action.
The conventional method has been remotely controlled
closed-circuit television (CCTV), a process by which a TV
camera is inserted into the pipeline to make an analog
recording. The camera is mounted on a track device that
propels it through the pipeline and records distance, time and
date. The device enables the operator to make audio
comments of observations, as well as color videotapes, DVDs
or still photos.
An alternative for smaller pipelines is a monitor on the surface
connected to a Kevlar sleeved fiberglass cable that is inserted
into the pipe for recording. Trenchless pipeline rehabilitation
is a cost-effective alternative to open-trench repairs.
The disadvantage of CCTV is that it is subject to operator
interpretation and varying quality of the TV pictures. Errors
are most likely to occur in assessing early defects or
deterioration that generally are not easily seen. As a result,
inspectors might believe that complete relining is the best
option, when in fact only spot repairs are needed, or that spot
repairs are done when complete relining is needed.
Digital decisions
For example, a Java-based analysis now in use makes data
less susceptible to operator error and enables users to scan and
measure joint separation and accurately assess pipeline
defects, including ovality of pipe and depth of cavities.
Software allows user-defined coding of defects for automatic
summary and analysis and user-defined reports. On-board
sensors capture vertical and horizontal pipe deflection since
installation, possible indicators of stresses from shifting soil
that can cause failure.
In its third generation, digital optical scanning technology
Digital data can be reviewed on line, stored on CD or DVD,
or seamlessly transferred to an asset management system for
further evaluation and easy archiving. When reviewing data,
the user can go to any point in the pipeline image instantly.
When combined with the analytical software that is available
today, digital data can help technicians more accurately assess
the condition of the pipeline — the key to cost-effective and
high-quality rehabilitation.
Chemical Considerations
On the other hand, if the problem involves a floor drain
used for photographic development or radiology waste, the
buildup likely is a combination of calcium carbonate from
the developer and iron deposits from steel wool silver
recovery.
Solid buildup is very difficult to clean. The best solution is
a cleaner specified for calcium carbonate and iron
removal. This liquid material is easy to use, safe for use in
iron and plastic pipe, and meets standards for non-corrosive
cleaners.
— Thomas Westerkamp
Mechanical cleaning includes everything from the old
standby manual plungers and augers to today’s faster and
more powerful motor- or engine-driven power cleaners.
Typical examples of mechanical cleaners found in a
plumber’s arsenal include:
Hand cleaners. Two common types are closet
augers and hand spinners. Closet augers with
flexible, 1/2-inch inner core cable can snake
through traps, even in newer, low-flow closets.
Workers also can use portable electric or battery-operated
hand spinners on small drain blockages in
sinks. They have a range of 50 feet and a vinyl-wrapped,
flexible inner core cable housed in a
plastic drum. They will not rust or dent and clean
easily.
Imaging technology
The gradual forms of pipe deterioration that maintenance and
engineering technicians face include drainpipe wall buildup,
erosion, corrosion, root invasion, cavities, sagging and cracks.
Managers need to assess risks, understand equipment options,
and sell a solution to management. These steps are best taken
before a middle-of- the-night emergency occurs.
More recently, facilities have begun using digital imaging to
assess pipeline condition. This technology is driven by the
inconsistency of CCTV data. Benefits of digital imaging
include more consistent and higher quality images, as well as
the ability to do computer-assisted data analysis.
Chemicals used for drain and pipe cleaning include
biological agents and a variety of inorganic chemicals.
These cleaners are application specific. For example, if the
problem involves a drain that is plugged with fats, grease
or oils, bio-augmentation drain cleaners provide a solution.
Naturally occurring microorganisms feed on waste buildup
and remove it from drains. Bio-augmentation is
environmentally safe and non- corrosive.
First published September 2003
