New (and old) Inspection Technologies - Michigan Water … Bowns Michigan WEA... · ·...

Stu Bowns

HYDROMAX USA

859-512-7878

Michigan WEA Collections Seminar

October 1, 2009

New (and old)

Inspection

Technologies

• History

• Flow Metering

• Zoom Cameras (Manhole Inspections)

• Focused Electrode Leak Location (FELL)

• CCTV Inspection

• Lateral Inspection

• Side Scan CCTV

• Large Diameter Pipe Inspection

(Camera/Laser/Sonar)

• What’s Next

Michigan WEA Collections

Seminar

October 1, 2009

After we started sewer systems, the need for inspection and cleaning quickly arose. The beginning of sewer line inspection was not with CCTV, but rather a primitive test which was only

really capable of finding infiltration or a failure of the so called inspection method.

First holes used to access the collection systems were referred to as lamp holes.

Only large enough to lower a lamp which was used to see if light would appear at the other end.

Later years the candle was dragged from one manhole to another by floating a thin line, such as a fishing line downstream with the flow and then retrieving it at the downstream hole. The thread was used to allow the operator to later pull a sled or a wagon on which the candle was placed. It was felt that, if the candle would still be lit at the far end if there was not a problem

with the line. If infiltration occurred, then it was thought that the candle would be extinguished. This of course also remained true if the candle went past a lateral with flow, or rolled over

during the inspection also. At the end of the day, the operator would have a simple set of data which showed if a line passed or failed. A failure usually meant a re-inspection. If an actual

failure did indeed occur the operator still had no idea where in the line the infiltration occurred.

Lamp-hole Designs

Source: The Designing, Construction, and

Maintenance of Sewerage Systems,

by H. Prescott Folwell, 1901

Source: www.sewerhistory.org


Seminar

October 1, 2009

Source: www.sewerhistory.org


Seminar

October 1, 2009


Seminar

October 1, 2009

TECHNOLOGY TO CONSIDER

• Primary Device

– Flume

– Weir

– Venturi

• Level (Depth)

– Pressure transducer

– Ultrasonic

• Velocity

– Doppler

– Radar

– Range gated doppler

WHAT, WHY, HOW ACCURATE, HOW LONG,

WHO IS USING INFO

FLOW METERING

FLOW METERING

Even with the accuracy of today’s equipment and the ability to look at real time data, site visits are necessary to insure accurate data.

Flow Debris

Depth Velocity Depth Flow

(in) (FPS) (in)

3 2 0 Calculated

3.25 2 0 11% Low

3 2.25 0 13% Low

3 2 0.5 8% High

6 2 0 Calculated

6.25 2 0 4% Low

6 2.25 0 11% Low

6 2 0.5 3% High

8-inch Line

Flow Debris

Depth Velocity Depth Flow

(in) (FPS) (in)

4 2 0 Calculated

4.25 2 0 9% Low

4 2.25 0 13% Low

4 2 0.5 5% High

16 2 0 Calculated

16.25 2 0 2% Low

16 2.25 0 13% Low

16 2 0.5 1% High

22 2 0 Calculated

22.25 2 0 1% Low

22 2.25 0 9% Low

22 2 0.5 1% High

24-inch Line

FLOW METERING

• Allows you to see up to 75 feet in

8” lines

• Can see more than 100 feet in

larger lines

• Helps determine if cleaning is

needed in association with

Preventative Maintenance

• Helps prioritize where more

detailed inspection is necessary

ZOOM CAMERAS

• Acceptance testing for new sanitary sewers

• Identify pipe defects including potential sources of infiltration and exfiltration (driven by flow monitoring data)

FELL SYSTEM

CCTV INSPECTION

•

CCTV INSPECTION

CCTV INSPECTION

Laterals comprise up to 50% of a municipalities collection system

Faulty laterals can be significant sources of I/I

Structural problems can lead to basement flooding and loss of service

Locate cause of backups to determine financial responsibility

Cross bores from other utilities

LATERAL INSPECTIONS

Lateral camera is attached to a

mainline camera

Mainline camera used to position

smaller lateral camera

Lateral camera launched into the

service line

Mainlines can range from 8” to 48”

Probe used in laterals from 3” to 6”

View up to 80 feet in the lateral

LATERAL INSPECTIONS

SIDE SCAN INSPECTION

12-inch, Re-enforced Concrete

“Un-wrapped” Side

Scan ImageFrontal view

• Frontal view identifies what appears to be a severely deteriorated

joint in need of repair

• The unwrapped side scan image identifies an intact joint with only

superficial surface defects. No repairs needed!


LARGE DIAMETER PIPE

INSPECTION

THE PROBLEMS:

• Illumination

• Image clarity

• Bypass pumping

• Personnel safety

• Data

LARGE DIAMETER PIPE

INSPECTION

ABOVE THE WATER SURFACE WITH LASER AND HIGH DEFINITION IMAGING

• Laser identifies loss of pipe wall from corrosion

• Laser calculates ovality

• Laser calculates deflection versus design

• HD Images

BELOW THE WATER SURFACE WITH SONAR

• Sonar determines lost capacity by calculating debris levels and volumes

• Major structural anomalies

LARGE DIAMETER PIPE

INSPECTION

9 inches

of silt

Sonar of a 30-inch line

LARGE DIAMETER PIPE

INSPECTION

Each brick face can easily be seen and the mortar loss

between each brick can be measured.

42”

32”

Typical

characteristics of

an egg shaped

brick sewer.

Less mortar loss

near the water

level, getting

worse towards the

invert.

LARGE DIAMETER PIPE

INSPECTION

Below the

water line in a

brick sewer

shows the

resolution that

is achievable

with sonar.

The invert

condition can

be seen using

sonar under the

cctv camera.

LARGE DIAMETER PIPE

INSPECTION

Enables inspection with minimum lighting requirements

Measurement of the exact shape of the conduit

Locate and measure the magnitude & location of deformations

Identification of connection location and position

LARGE DIAMETER PIPE

INSPECTION

LARGE DIAMETER PIPE

INSPECTION

• HD Image, Laser and Sonar data

continuously collected

• Sewers >30 inches in diameter

• Bypass pumping is not needed

• Capable of performing

continuous inspections for

more than a mile

• Easy to interpret data

LARGE DIAMETER PIPE

INSPECTION

LARGE DIAMETER PIPE

INSPECTION

• Laser data collected 12x per second

• Sonar readings taken 1x per second

• HD Images captured 6x per second

LARGE DIAMETER PIPE

INSPECTION

LARGE DIAMETER PIPE

INSPECTION

WHAT’S NEXT

A SENSOR THAT CAN

IMAGE OUTSIDE THE PIPE

WALL TO IDENTIFY VOIDS

AND PIPE THICKNESS

• There are numerous technologies used to

investigate the collection system

• No one tool identifies all the problems

• New and emerging technologies are available to

provide better data


Seminar

October 1, 2009

THANK YOU – QUESTIONS?

[email protected]

New (and old) Inspection Technologies - Michigan Water … Bowns Michigan WEA... · ·...

Documents

Transcript of New (and old) Inspection Technologies - Michigan Water … Bowns Michigan WEA... · ·...