Buried Piping

8/13/2019 Buried Piping

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What Lies Beneath

A Comprehensive Look at the

Inspection of Buried Plant Piping

Brant Shields



Technical Manager

Over 20 years in the inspection and NDE field.

Currently hold API 510 Inspection of Pressure essels and API

!5" Inspection of A#ove $round %tora&e 'an(s

$uided )ltrasonics *evel I +advanced, and C%-IP *evel II.

Certified *evel II in )ltrasonics Penetrant testin& /a&netic

Particle testin& and isual inspection.

I also copleted trainin& in Direct Assessent of #uried &as and

liuid pipelines 3 assessent and $- assessent of cased

road crossin&s.

I have ana&ed nuerous pro4ects involvin& ECDAICDA on

natural &as as 6ell as liuid pipelines.



Buried Plant Piping Inspection

Goal

)tili7in& direct assessent

ethodolo&y to inspect

#uried process pipin& to

a8ii7e results and costeffectiveness.



Buried Plant Piping!"#stacles

9 :ound in ost all facilities

9 /ost non; pi&&a#le

9 %hort len&ths

9 Coplicated

confi&urations

9 *iited access

9 In soe cases; liited

(no6led&e



9 Developed fornatural gastransmission

pipelines

9 Used for theinspection of non-piggable pipelines

9 Uses complimentarytechnologies toperform inspections

Direct Assessment- History



Five Steps of Direct

Assessment

9 Pre-Assessment (Gather Information on the

System)

9 Indirect Examination (Gather Data on System)

9 Direct Examination (Excavation of Priority Areas)

9 Remediation (Repair or Replacement)

9 Post-Assessment (Effectiveness of Remediation)



Inspection of Buried Piping

9 'here are any different

considerations to #e &iven 6hen

inspectin& #uried pipin&. %oe

include<

9 1. Pipin& location si7e and

len&th

9 2. Accessi#ility of #uried portion

9 ". Any value of cathodic

protection

9 =. Potential for corrosion



$istorical %ata

9 evie6in& past history canprovide a 6ealth ofinforation. 'his inspectionpractice is already used #ythe a4ority of en&ineer andinspection personnel.

9 >ears of service

9 Past corrosion pro#les

9 %iilar service

9 Chan&es in service

9 Pipin& specifications



Buried Piping! %amage Mechanisms

9 3uried pipin& typically involvesore plannin& and liited accessto perfor siilar a#ove &radeinspections. %everal conditionsarise 6hen perforin& inspectionson #uried pipin&; only the solutions&et ore difficult.

9 %oe daa&e echaniss

9 ErosionCorrosion

9 InternalE8ternal

9 Coatin& dis#ondent

9 Inherent ill defects

9 Insta#ility

9 'hird Party Daa&e

9 %oil to Air Interface

9 Environental crac(in&





&evie' of Techni(ues

9 3y utili7in& soe ethods fro DA in con4unction6ith advanced NDE ethods users can identifyhi&h conseuence areas. /ethods to #e revie6ed<

9CIPS )Close Interval Potential %urvey,

9 %C*G (Direct Current Voltage Gradient)

9 AC*G (Alternating Current Voltage Gradient)

9 GW +$uided -ave )ltrasonics,

9 A+T (Automated Ultrasonics)

9 AC,M (Alternating Field Current Measurement)



9 /ost cases; this is

already perfored if

the pipin& in uestion

has CP9 /easure the pipe to

soil potential

9 Current is interrupted

to provide Btrue

potential

9 Assessent e8tends

for the entire len&th of

the pipin&

Close Interval Potential Surve-

)CIPS.



9 Measres volta!e

!radient on "ried

pipin!

9 Measres the crrent

attenation todetermine coatin!

#ality and inte!rity

9 Difference is spplied

crrent D$%G ses plsed

D$ crrent

A$%G ses isolated

A$ crrent

%irect and Alternating Current *oltage

Gradient

)%C*G / AC*G.





9 &ing of transducers)collar0tool. is placed

on the pipe

9Pressured 'ith air )23

to 43 psi.

9 Instrument and laptop

connected

9 Waves sent do'n the

pipe #i!directionall-

9 &esults are anal-1ed

Guided Waves! General Information



Guided Wave +ltrasonics

9 5uantitative method

9 A#ove0Belo' grade

9 Limited #- somepiping configurations

9 %istance limited #-

soil0coatingconditions

9 Can locate areas ofpro#a#le concern



GW Applications

9 Soil to air interface

9 Buried piping 'ith someaccessi#ilit-

9 %ike0containment penetrations

9 Sleeved road crossings



A+T General Information

9 Technolog- driven to ensure complete

coverage

9 6liminate human error

9 +ses semi or completel- automated raster t-pe

or encoded scanning s-stems

9 Man- s-stems include A!scan7 B!scan and C!

scan displa-s )%!scan also availa#le.



Automated +ltrasonics

9 5ualitative results

9 Scanned image in colormap or gridded format

9 $igh temperatures can #e

inspected

9 Limited configurations

9 Piping has to #e fairl-clean

9 All pipeline coatings haveto #e removed



A+T Applications

9 An- piping 89 and greater )t-picall-.

9 Guided Wave verification points

9 Pipeline surve-s for detailedinspection



AC,M General Information

9 +ses an alternating current field 'hich flo's

on the surface of the pipe #eing inspected

9 %istur#ances in the current field locate cracks

9 +sed as a replacement for conventional Magnetic

Particle and Li(uid Penetrate testing

9 Standard pro#es can operate through non!

conductive coatings up to 3mm thick



Alternating Current ,ield

Measurement

9 Capa#le of detectingand si1ing cracks in

most metals

9 +ses B: and B1components to(uantif- and si1ecracks

9 Can provide accuratedata for engineeringcalculations



AC,M Applications

9 Locating environmental

cracking )SCC.

9 Si1ing cracking defects



The “Miracle Tool

9%iply does not

e8ist.

FFAll ethods and technolo&ies should #e used

to coplient other inspections.



!eys to a Successful

"nspection

9 Ipleentation of the correct inspectiontechniue

9 Pro;active use of ne6 technolo&ies

9 Gno6 the liitations of the techniue

9 In ost cases the euipent is only as &oodas the technician.



Thank ;ou #

9 HuestionsCoents

Buried Piping

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