> **Quarterly Report**
>
>  
>
> Date of Report: *August 1, 2006*
>
> Contract Number: *DTPH56-06-T-0004*
>
> Prepared for: *DOT*
>
> Project Title: *Plastic Pipe failure, Risk, and Threat Analysis*
>
> Prepared by:  *Gas Technology Institute*
>
> For quarterly period ending: *June 30, 2006*
>
> SCH Date CMPL Date
>
> > Task \# 1: Project Advisory Group 04/30/2006 07/19/2006 \*MS

-   **Technical Status**

> The work in Task 1 was to [Form a Project Advisory Group (PAG) for
> Participation and Guidance]{.underline} on the project. GTI has
> completed the establishment of the PAG; the PAG includes members of
> APGA, APGA RF, and NGA as well as members from three gas distribution
> companies.
>
> The GTI team has also begun working on Task 2. Task 2 involves
> [conducting a Literary Search to Identify Risks and Threats to Plastic
> Gas Pipes by Soliciting Information From Gas Distribution Companies
> and Others]{.underline}. GTI has been reviewing available publications
> including DOT OPS Distribution Incident Data, Pipeline Accident
> Briefs, AGA publications and conference proceedings, as well as
> plastic pipe service manuals and integrity management manuals.
> Additionally, GTI conducted a review of GTI's 30-year database on
> plastic pipe field failures, causes, and risks.
>
> > Task 3 involves [conducting surveys and questionnaires of AGA, APGA,
> > NGA, PPDC, etc. to Solicit Information on Plastic Gas Pipe Field
> > Failure Analysis and to develop a Database]{.underline}. GTI has
> > begun developing a series of questions for the survey. A couple of
> > example questions are shown in the table below. GTI team has also
> > started preparing travel plans and contacting gas distribution
> > companies to visit a number of gas companies to discuss the survey
> > and to solicit plastic pipe failure information.

  ----- --------------------------------------------------- --------------
  16    How many In-service plastic pipe field failures     
        have occurred in the last:                          

        year?                                               

        5 years?                                            

        10 years?                                           

  17b   Have you had any failures caused by:                

        Rock Impingement?                                   

        How many?                                           

        Pipe Size?                                          

        Pipe Material?                                      

        Time in Service (in years)?                         

        Year of Installation?                               

                                                            
  ----- --------------------------------------------------- --------------

> Task 4 is [Address and Assess Threats Associated with Brittle-Like
> Failures over Time in Plastic Pipes and in Fusion Joints Susceptible
> to Premature SCG Failures.]{.underline} GTI began soliciting from gas
> companies, pipe test samples of a few older lots of plastic gas
> materials that may be susceptible to premature brittle-like cracking.
> GTI has already received a few pipe samples of these materials;
> several of these received pipe samples have been cut into test
> specimens and prepared for accelerated long-term stress-rupture
> laboratory tests.

-   **Business Status**

> GTI held a teleconference attended by more than eight gas distribution
> companies to present the project objectives, tasks and approach and to
> discuss qualitative and quantitative risk assessment (RA) techniques
> to be implemented in soliciting a database and for establishing a
> relative risk indicator. GTI has also held several discussions with a
> few gas distribution companies directed at soliciting plastic gas
> pipes that failed in field service for the purpose of conducting a
> root-cause failure analysis.

-   **Schedule**

> Task 1 was to be completed by the end of April. It was not completed
> until mid-July as we waited for confirmation from several
> organizations.

-   **Payable Milestones**

> The submission of this quarterly report is the first payable
> milestone.
>
> **Results and Conclusions**: 
>
> The review of the GRI database showed that in the last 15 to 20 years,
> GTI/GRI conducted several surveys of the gas distribution industry to
> determine the types, causes and approximate frequency of PE pipe field
> failures other than those due to excavation damage. During this time
> period, GTI/GRI also held several meetings with gas industry advisors
> with a wide geographical representation to solicit qualitative
> information and input on plastic pipe field failures. These early
> surveys and meetings provided important information on the types and
> the frequency of many types of plastic pipe field failures. On the
> basis of GTI/GRI surveys and meetings, conducted through about 1998,
> it was found that:

-   The largest number of plastic pipe failures occurred and initiated
    at defects in saddle- and socket-fusion joints and grew in a Slow
    Crack Growth (SCG) mode resulting in a leak.

-   The second highest group of plastic pipe failures were at socket-
    and butt-fusion joints; however, these were due primarily to poor
    workmanship that resulted in a cold bond, lack of bond penetration,
    or other similar factors.

-   The third largest group of plastic pipe failures were due to
    squeeze-off, impinging rocks, or pipe bending; these initiated and
    grew in a SCG mode.

> **Issues, Problems or Challenges**:
>
> There is a possibility that the GTI team will experience some delays
> while soliciting information from gas companies. GTI travel will be
> scheduled around gas company availability. Since multiple trips are
> planned with time between trips being necessary for compiling a
> database, there exists the possibility of scheduling conflicts.
>
> **Plans for Future Activity**:
>
> GTI plans to host a "Kick-off" meeting with PAG members and also
> travel to gas companies to gather information on plastic pipe
> failures. Over the next quarter, GTI will continue working on the
> survey and literature search and on conducting laboratory tests on
> older plastic gas pipe failures and materials susceptible to brittle
> failures.
>
> **Public Page**:
>
> The Plastic Pipe Failure, Risk, and Thread Analysis project is
> currently underway at Gas Technology Institute. The project seeks to
> identify failure risks and threats to plastic gas pipes, perform
> root-cause analysis to identify which types of defects lead to
> failure, and prioritize the risks and threats. GTI identified seven
> tasks needed to accomplish these objectives.
>
> Task 1 called for the formation of a Project Advisory Group (PAG).
> This task has been completed and marks the first accomplished
> milestone. The PAG includes members of a few gas industry associations
> as well as members from gas distribution companies. These individuals
> will participate and provide guidance.
>
> GTI has also worked on tasks 2, 3, and 4, which are all related to
> information gathering. Task 2 entails a literary search. GTI has
> collected a large number of publications and is currently reviewing
> them and compiling the information. A 30-year GTI/GRI database was
> reviewed. The results of this review showed the largest number of
> plastic pipe failures resulted from saddle- and socket-fusion joints
> followed by socket- and butt-fusion joints. Squeeze-off, impinging
> rocks, and pipe bending also resulted in plastic pipe failures.
>
> Task 3 work requires solicitation of plastic pipe failure information
> from gas associations and distribution companies. GTI has been
> developing a survey for this purpose as well as forming travel plans
> to visit various organizations to obtain data.
>
> The work GTI has performed on Task 4 has been accomplished through the
> use of GTI's plastic pipe analyses laboratory. GTI has accepted a few
> pipe samples that are now prepared for accelerated long-term
> stress-rupture laboratory tests.
>
> The information gathered thus far will be compiled into a database
> which will later be used to formulate equations and indexing
> techniques to calculate relative failure risk for plastic pipe
> segments.
>
> Dr. Michael Mamoun
>
> <mike.mamoun@gastechnology.org>
>
> 847.768.0953