Large Bore Piping Material

8/2/2019 Large Bore Piping Material

1/22

Material Specifications forLarge Diameter Watermains

Regional Council

November 10/05


2/22

Material Specifications for Large

Diameter Watermains

Background

Material Review Committee CAO & Regional Chair meet withManufacturer

Members of Council/Staff/Manufacturer

Presentations Request for Information from

Manufacturer

Regional Council PW-A1 Report Regional Council PW-B1 Report &Deligations


3/22

Material Specifications for Large DiameterWatermains

Water Distribution in Region of Peel

System is large and complex and is thesecond largest in Ontario at over 3,500 km inlength.

Our water system serves two main purposes:

To provide a safe, potable water supply tothe residents commercial, industrial andinstitutional users

To provide water for fire protection


4/22

Material Specifications for Large Diameter

WatermainsPVC Watermain in Peel

PVC pipe is a widely used and a valued

material in Region of Peels water distributionsystem.

PVC pipe comprises 50% of our existinglinear system and 95% of all new installations.

PVC watermains have a definite andappropriate application in the waterdistribution industry.


5/22


WatermainsPipe use in Region of Peel Water Distribution

(Percentage of pipe installed over total pipe installed)

0

20

40

60

80

100

2000 2001 2002 2003 2004 2005

PVC CONCRETE


6/22


WatermainsMaterial Review CommitteePipe Comparison

Cost

Failure Mode

disinfection

repair

Operational Issues

fittings

bedding

Installation Issues

external loads surge pressures

Design/Specifications


7/22


Typical Failure Mode for Large DiameterWatermain

Major watermain breaks can occur in any pipematerial

Concrete Pressure Pipe & Coated Ductile IronPipe failure is generally characterized bysmall holes or localized fractures.

In the Peel experience PVC Pipe failure isnearly always catastrophic. Characterized bylongitudinal splitting and shattering of sectionsof pipe.


8/22


Watermains

PVC Watermain Failure Mode

When catastrophic failure of PVC pipe occursit is accommodated within the smallerdiameter piping system.

System impact is significantly less with smallerpipes and contamination events can be dealtwith through flushing, and/or swabbing anddisinfection.

The prevalence for catastrophic failure and theresulting impacts on the system create seriousconcern regarding the use of large diameterPVC water pipe.


9/22

PVC water pipe is subject to catastrophic failure.

Since the damaged area is more extensive, the potentialfor a large contamination event is significantly increased.

The larger the PVC watermain, the greater the impact. The manufacturer has confirmed that large diameter pipes

fail in the same manner as small diameter pipes.

Material Specifications for Large Diameter WatermainsCase Study: Large Diameter Watermain Break


10/22


WatermainsCase Study: Large Diameter Watermain Break

June 30, 2005

900 mm (36-inch)concrete watermainis drilled through bya contractor nearthe intersection of

Rutherford Rd. S. &Bramsteele Rd.,Brampton.

Traffic is reduced to

2 lanes for theduration of the longweekend.


11/22



The localized area

was excavatedwithout additionaldamage to the pipe.

The hole wasrepaired with aconcrete patch andwelded saddle clamp.

No debriscontaminationoccurred.


12/22



This repair took 3days to complete.

Generally, the sizeof the concrete orductile ironwatermain does

not significantlyincrease theimpacts of a break.


13/22

Material Specifications for

Large Diameter WatermainsCase Study: Large Diameter Watermain

Break

If the Rutherford Rd. mainbreakhad been 900 mm PVC, theflooding would have been farmore extensive.

The street would have beenclosed to all traffic.

Excavation and restoration

would have been significantlymore extensive.

A 300mm PVC mainbreak at Orr

Rd. & Inverhouse Dr.,Mississauga


14/22


Peels Watermain Break History

97% Concretepipe > 400mm

diameter

1.16CPP

All PVC < 400mmdiameter

1.34PVC

NotesBreaks/100km/yrWatermain Material


15/22


PVC Watermain in Other Municipalities

A survey of other municipalities revealed that:

1. engineers and operational staff are generallyapprehensive in allowing PVC pipe for largediameter watermains &

2. use of large diameter PVC is usually very limited oron a trial basis.

3. Hamilton, Ottawa and Durham staff have notsupported its use.

It is very difficult to find data that shows thelong-term performance of large diameter PVCwater pipe.


16/22


Diameter Watermains

Letter received November 2, 2005 to

Chair Emil Kolb from Bruce Hollands,The Rothwell Group Inc. Decontamination Procedures

Potential Accidental Pipe hit / Montreal

Event Simulated Field Break Failure

Safety Cautions

Limited Large Diameter Use Safe Drinking Water Act / Watertight

Prevalence of Use.


17/22


Diameter Watermains

Memo January 9, 2005 to Veso Sobot,

IPEX from M.B. Fielding, P.Eng. Procedures available yet deleteriousmaterial removal extremely difficult.

Memo October 28, 2005 to Bruce

Hollands, The Rothwell Group fromAndy Valickis, P. Eng., Ontario CleanWater Agency. Procedures available, only longitudinal

catastrophic OCWA does not recommend pipe use, itsthe owners decision Dan Atkinson, VicePresident Operations.


18/22


Diameter Watermains

Letter October 25, 2005 to Mitch

Zamojc, P.Eng., from Bob Walker P.Eng., UniBell Pipe Association

Questions Responses

1. Field Testing None required, information available

October 12, 2005, Montreal Event reference

2. Modes of Failure

Similar to other pipes

Discussion on rates of failure


19/22


Diameter Watermains

3. Other causes of Failure

99% as described by Peel

4. Diameter & Types of Failure Increased diameter has little effect

5. Operators & General PublicDangers with CatastrophicFailures

Consequence of damage primarily afunction of pipe diameter and operatingpressure.


20/22


Diameter Watermains

6. International Data on Life Span &

Break Rates Information continue to be collected

NRC most comprehensive

7. Impact of UV Light Suggest that pressure rating & stiffnessincrease after two years exposure

8. Risks to Operators when Tapping Function of diameter and operating pressures

Training from the industry is available


21/22


Diameter Watermains

Conclusion

Each pipe material, PVC, CPP, DI hasan application in the watermain industry

Data is inconclusive to demonstrate

appreciable cost savings by pipe type Customer Service impacts are greater

from catastrophic watermain failures

Catastrophic failure mode is mostprevalent in PVC pipe.


22/22


Recommendations

Continuation of the use of PVC Pipe up

to 300 mm diameter.

Concrete pressure pipe and

coated/lined ductile iron pipe for 400mm and greater.

Documents

Large Bore Piping Material