non destructive examination of piping from the inside · pdf filenon destructive examination...

Non Destructive Examination of

Piping from the Inside – Using

INETEC’s “Zenith” Robot

IAEA/EPRI International Technical Meeting on Aging Management of Buried and Underground Piping and Tanks for Nuclear Power Plants,

13-15 October 2014, Charlotte, North Carolina, USA

Krunoslav Markulin

INETEC Institute for Nuclear Technology

Dolenica 28, 10250 Zagreb, Croatia

[email protected]

Content • Introduction

• Piping Overview

o Buried piping dimensions and geometry

• Piping Inspection Robot

o Zenith pipe inspection robot

• Piping Inspection

o NDE methods and techniques

o Inspection demonstration

o Outline of piping inspection

• Conclusions

Introduction Inspection requirements

• NDE (surface and volumetric examination) of piping

from the inside with different ID/OD dimensions

• Providing confidence that a given NDT inspection is fit

for its purpose by:

o Demonstration of piping inspection manipulator

motion capabilities through the mockup

o Assessing inspection methods to determine

whether they are capable of attaining their

objectives

Piping overview Pipes dimensions overview

Inspection Object OD / ID Wall Thickness Length

Buried Piping 349 / 325 mm

13,74 / 12,79’’

12 mm

0,47’’

approx. 60 m

197 ft

Buried Piping 239 / 219

9,40 / 8.62’’

10

0,39’’

approx. 60 m

197 ft


6,73 / 6,26’’

6

0,24’’

approx. 60 m

197 ft


4,65 / 4,25’’

5

0,20’’

approx. 60 m

197 ft

• Inspection objects are buried pipes - in direct contact with concrete.

Piping geometry overview

• One side access

• Straight/horizontal, vertical and

bend line (a lot of bends)

Piping overview


Piping overview

• One side access




• One side access



Piping overview


• Piping with longitudinal weld seam and

protruding weld root

• Piping with circumferential weld seam

and protruding weld root

Piping overview

Overview

• Zenith is pipe inspection robot developed by INETEC to work in

a harsh environment of the nuclear power plant

• Full scope of ET, UT and/or VT

• Dry as well as underwater operation

• Reliable inspection of the pipes from the ID

• Interchangeable parts for multiple pipe diameters

• Flexibility for passing the bends but also a large driving force to

overcome vertical sections

• Robot is equipped with three video cameras

• Cable with evenly spaced wheels to reduce friction

and avoid a stuck

Zenith pipe inspection robot

Main components

• Driving mechanism with gripping modules and

unique flexible lead screw provides a huge

driving force within a compact design

• Motor drives are integrated into the robot to

reduce a noise in the signal cables

• All wheels have remotely controlled retraction

system used in emergency situations and to

avoid obstacles in the pipe


Drive mechanism

Probe module

Electronics &

pneumatics

Cable

Drive mechanism

• Consists of: front centering module

with a camera, middle gripper with a

nut, rear gripper with a motor assembly

and flexible lead screw.

• Moving like a worm inside a pipe locking

and releasing the grippers and rotating a

screw in corresponding direction.

• Driving force (FD) is more than 2000 N

in both direction at working pressure of

3.5 bars.

• Linear speed is up to 100 mm/s (4’’/s)


Probe module

• Has rotating mechanism and pneumatic

system for pressing the probes against

inner surface of the pipe

• Designed to carry up to 6 probes

• Each probe is independently pressed to

the pipe wall allowing smooth pass over

the weld and scanning inside the bend

• 400 degree rotation

• Axial and circumferential scans

• Water supply


Control system

• Manipulator control is arranged as three

level control system (PC, control box

and manipulator)

• Main controller is located outside in the

control box and connected with PC via

TCP/IP protocol

• Motor drives are integrated inside the

manipulator reducing noise in the signal

cable


Video/VT system

• 3 waterproof high

radiation resistant

cameras looking at

points of interest


Piping Inspection NDE methods and techniques

• NDE Methods – VT (surface exam.)

o Conducted to detect corrosion deposits

from ID side

o Unclean ID surface (debris) or stagnant

water/fluid inside piping obscure VT

examination

o Will not prevent leaks but only detects

leakage


• NDE Methods – ET (surface exam.)

o Sensitive to the presence of surface breaking cracks

and subsurface cracks near the surface being

inspected

o Provides detection, length and depth (near surface

defects) sizing

o Does not require coupling media but must be in

contact with the surface for best test sensitivity

o Bend line and protruding weld root area is more

challenging for inspection


• NDE Methods – UT (volumetric exam.)

o TOFD method (sensitive and accurate) in combination with

conventional probes

o TOFD works well for detecting tips and perturbations of the surface

signals & sizing of both axial and circumferentially oriented cracks

o 0 degree for thickness measurement

o Provides detection, length and depth sizing

o Require coupling media

o Bend line and protruding weld root area is more challenging for

inspection


Sled #6 Sled #1

Sled #2

Sled #5 Sled #3

Sled #4

• Axial/circumferential scanning (example)


Probes used Piping Area

TOFD Axial Shooting Entire pipe thickness

TOFD Circ Shooting Entire pipe thickness

0° Long. Wave Probe Entire pipe thickness

ET Probe ID pipe surface

Creep Wave Probe (77°) ID pipe surface


60° Long. Wave Probe OD pipe area




Probes used Piping Area

TOFD Axial Shooting Entire pipe thickness

TOFD Circ Shooting Entire pipe thickness


ET Probe ID pipe surface

Creep Wave Probe (77°) ID pipe surface


60° Long. Wave Probe OD pipe area

Piping Inspection Inspection demonstration

• Demonstration was divided into the

two parts

o First part (equipment) of the

demonstration had purpose to

demonstrate piping inspection

manipulator motion capabilities

through the mockup. The aim is to

pass the mockup to the required

length.

Piping Inspection Inspection demonstration

• Demonstration was divided into the two

parts

o Second part (procedure & personnel)

of the demonstration had purpose to

demonstrate inspection system

capabilities and sensitivity on the

piping with artificial flaws, providing

confidence that a given NDT

inspection is fit for its purpose.

Piping Inspection Outline of piping inspection

• NPP site

• Field proven concept

o 1st Inspection: July 2014

o 2nd Inspection: August 2014

o 3rd Inspection: Oct.-Nov. 2014

• NDE Methods

o UT & ET

• Inspected piping

o ID/OD 349 / 325; T=12 mm

o ID/OD 239 / 219; T=10 mm

Conclusions • Reliable inspection system (procedure, equipment and

personnel) is one of the key parameters in NDE of buried

piping.

• Increasing requirements to the safety enhancement during plant

operation require continuous research and development and

implementation of the new technologies and NDT examination

techniques.

• Repair module is the next step of development.

Thank You for Your Attention

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