Crack Data System

Why does NDT data need upgrading?

NDT inspection data for visual type inspections of in-service equipment have remained the same for more than half a century.

Industry has evolved, with a greater focus on maintenance and reliability. It is time for NDT data to catch up and provide the information that is truly needed for risk management and repair management. Simply providing visual crack length is insufficient for these purposes.

Please contact us if you have any questions or if you want to implement the Crack Data System

For example, consider a nominal 200mm crack that is found in a chassis or boom. In reality, this 200mm crack may be any of the following;

  • A 200mm crack that is 5mm deep in 25mm plate

  • A 200mm crack that is 15mm deep in 25mm plate

  • A 200mm crack that is full thickness through 25mm plate

  • A 200mm crack that is full thickness through 25mm plate but has propagated from the internal side, with an internal length of 500mm

  • A 200mm crack that is in a Non-structural element compared to one that is in a Vital location

  • A 200mm crack at the weld toe compared to transverse crack through a corner weld.

There is a significant difference in the level of risk presented as well as the repair requirements for each of these cracks in terms of repair duration, welder competence and also quality assurance and control.

It is clear that traditional NDT data is severely lacking. This is why the Crack Data System was developed.

Overview

The Crack Data System fully describes the following key features of cracking that are relevant for risk management and repair assessment:

  • The location where the cracking is in terms of risk to asset operation

  • The nature and features of the cracking

  • Whether the cracking is internal or external initiation

  • Length of crack on internal side (of hollow sections)

  • Length of largest individual crack in a zone of cracking

  • Depth of cracking

  • Thickness of the material



Condition Severity Thresholds

Generate standardised thresholds based on crack length for the various location types. See this link for more details.

Assess the risk at a glance based on the location type

  • Vital, Structural or Non-Structural

Planning

Better estimate the time required to carry out the repair based on the total repair volume (length, depth and material thickness)

Welder Competency

Allocate the right welder to the repair to ensure it is done right

Crack Location Type

By simply categorising as Vital, Structural, or Non-Structural, it makes it easier to know how important a crack is.

Also, standardised threshold values can be developed for condition severity based on the location type.

Crack Dimensions

Total Length - Overall visible length is all that is typically reported from NDT inspections

Maximum Length - Informs whether there are a number of smaller cracks that make up the larger, and also enables estimating of crack depth. This is also used to indicate crack length internally.

Thickness - Knowing the thickness of the section that is cracked is important for estimating the repair duration, as well as assisting the Welder in knowing how deep to gouge.

Nature of the Cracking

Location - Better understand and manage risk

Type - The nature of the cracking assists in understanding the cause, risk, and how to repair it

Depth - Simple categorisation of depth allows improved risk management, as well as making it easy to assign a Welder with the appropriate competency for the repair.

Crack Examples

Location

The location of a crack is important! with the Crack Data System you don't need to look through photos to be able to know where cracking is in order to manage risk and determine your repair priority

V200LF25

  • 200mm long crack that is full thickness in a Vital location in 25mm plate

S200LF25

  • 200mm long crack, at the weld toe, full thickness in a Structural location in 25mm thick plate


N200LF25

  • 200mm long crack, full thickness in a Non-structural location in 25mm plate

Crack Type

The nature of the cracking is important for determining the repair plan and methodology. Also, knowing the type of cracking allows a deeper understand of the potential causes of cracking.

S200LP25

  • 200mm Longitudinal crack that is parallel with the weld, partial depth in a Structural location in 25mm plate


S200TP25

  • 200mm crack that is Transverse to the weld, partial depth in a Structural location in 25mm plate


S200I30P25

  • 200mm long Intermittent crack, with the largest individual crack being 30mm, partial depth in a Structural location 25 mm thick

S200M30P25

  • 200mm long zone of Multiple cracks, with the largest individual crack being 30mm, partial depth in a Structural location 25 mm thick


S200X120F25

  • 200mm total length of Complex cracking (branching, intersecting, propagating through multiple plates etc), with the maximum individual crack length of 120mm, full thickness in a Structural location 25mm thick.


S50XP25

The “X” can also be used to indicate cracks that are inaccessible for repair without major equipment disassembly.

Depth and Thickness

Cracks are 3 dimensional. Knowing the depth and material thickness allows more accurate estimates of required repair duration for planning purposes. It also allows simple welder competency requirements to be established based on whether the crack is full thickness in a hollow section.

S200LS25

  • 200mm long crack, at the weld toe, shallow depth (<5mm) in a Structural location in 25mm thick plate

S200LP25

  • 200mm long crack, at the weld toe, partial depth in a Structural location in 25mm thick plate

S200LF25

  • 200mm long crack, at the weld toe, full thickness in a Structural location in 25mm thick plate


Internal Cracking

S0L200P25

  • No visible cracking at external surface (0mm), but 200mm at internal surface (eg weld root), partial thickness in a Structural location in 25mm thick plate. This is typical of cracking found via Ultrasonic Testing

S200L500F25

  • 200mm long crack in the weld cap, and 500mm along the weld root (cracking from internal), full thickness in a Structural location in 25mm thick plate.

Example Inspection Report

The Crack Data System can easily be used by your NDT service provider or Condition Monitoring team and presented in their inspection reports

Hitachi EX5500 Inspection Report Example.pdf

Please click this link if the document does not load in this page

About the Crack Data System

  • As part of our mission to improve crack repair management, WQMS developed the Crack Data System to upgrade NDT data so that the necessary information is provided for risk and repair management

  • The Crack Data System is OPEN SOURCE. Why? Because good things need to be shared, and everyone will benefit from using the Crack Data System. It is a foundation for our AICARM Framework, and supports the Mining Welder Competency, but it can also be used to great benefit just by itself.

  • What's the catch? There is none. We are making all the basic information for the Crack Data System publicly available. However, formal training of NDT technicians is recommended. Basic training may also be helpful in introducing the Crack Data System to site and familiarising maintenance personnel with how to use it

  • Want to know how to implement it? - Call us for free advice 02 5516 1008 or send us an email info@wqms.com.au