PART 1

INTRODUCTION TO POST-CONSTRUCTION

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

INTRODUCTION TO POST-CONSTRUCTION ACTIVITIES

The term post construction refers to the activities which assure the safety of pressure vessels (and other pressure equipment) after they have been put into service (some call maintenance)

Inspection rules are those dictating the minimum frequency of inspection and the scope, methods and evaluation of results of inspections

Flaw evaluation involves the assessment of flaws detected during inspection. What is acceptable and what is not (also called fitness for service)

Repair is an activity to restore a degraded vessel to its original design capability

Alteration is an activity which provides for the re-certification of a vessel for design data different from that oforiginal design. If re-certification is possible without a change to the hardware, this is a re-rate

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

INTRODUCTION TO POST-CONSTRUCTION ACTIVITIES

These activities are normally performed at pre-scheduled outages. In such cases, proper planning must be performed prior to shut down, to minimize down time

Sometimes shut down is unscheduled and due to a problem. Time is again of the essence

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

INTRODUCTION TO NBIC AND API-510

The ASME Code Section VIII (Divisions 1,2, and 3), as well as most other pressure vessel codes, contain rules for new construction only. As soon as a vessel is stamped, the jurisdiction of Section VIII ceases. For in-service operations such as inspection, flaw evaluation, repair, and alteration a number of other codes and standards are available

In the U.S. and Canada, the most commonly used documents are the NBIC and API-510The NBIC is acceptable by almost all jurisdictions and required by many. This document was originally intended for power plants but is used extensively by petrochemical industry

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

INTRODUTION TO OTHER DOCUMENTS

There are a number of other API documents covering inspection and repair/alteration rules for pressure equipment, such as: API-570 For inspection and repair/alteration of piping RP 572 For recommendations on detailed inspection of

pressure vessels RP 573 For inspection of boilers RP-574 For inspection of piping RP 575 For Inspection of tanks RP-576 For inspection of relief valves Publ. 581 For risk based inspection Std. 653 For inspection and repair of tanks

Some of these publications are rather old, but they are useful references

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

INTRODUCTION TO OTHER DOCUMENTS

API-579, entitled Fitness-for-Service, has rules for evaluation of various flaws that may be detected during inspection

There are a number of European and Japanese codes and standards related to inspection, evaluation, and repair of pressure equipment

ASME Post Construction Committee has published a number of detailed repair procedures and is in the process of preparingand publishing several more

ASME Inspection document will be published shortly. Will have extensive rules for qualitative, quantitative , and semi-quantitative methods of establishing inspection periods

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

PART RB

Based on corrosion rate, the remaining life is calculated by the following formula:Remaining life = [t(actual)-t(required)]/corrosion rateWhere, t(actual) is the thickness measured at the time of inspection, t(required) is the minimum required design thickness, and corrosion rate is the expected annual corrosion rate, based on history

The corrosion rate for in-service vessels is based on previous service

Corrosion rate = [t(previous)- t(actual)]/[years since last inspection]

For new vessels, corrosion rate must be based on same or similar equipment or based on experience and judgment

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

PART RB

The inspection interval ( max. period between inspections) shall not exceed one half of the remaining life or ten years, whichever is less

Where the remaining life is less than 4 years, the inspection interval may be the full remaining life up to a maximum of 2 years.

A number of conditions may affect the remaining life. Conditions such as the following shall be reviewed and the remaining life adjusted, if needed: Any deterioration such as bulging, sagging, stress

corrosion cracking, fatigue cracking, hydrogen blistering, and erosion

Any material degradation such as hydrogen attack, carburization, and graphitization

Thermal shock Excessive temperature Pressure surges Vibrations

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

PART RB

The measured thickness t(actual) used for determination of corrosion rate and remaining life is not at one point, but the average thickness over a certain length

For vessels subject to pressure only, the averaging shall be done over an axial distance, since the circumferential stresses control the design

For vessels subject to overturning (usually due to wind or earthquake), the averaging shall also be done over circumferential distances

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

PART RB

The number of points over which the averaging is done is not specified and is at the discretion of the Inspector

Pitting -In addition to checking average thickness over areas of general corrosion, pitting must also be evaluated

Scattered pitting may be disregarded provided that the following three conditions are met:

1) The depth of no one pit is greater than the required thickness (exclusive of corrosion allowance

2) The total area of the pits does not exceed 7 sq. in. within any circle of 8 in. diameter

1) The sum of the diameters of pits along any straight line within an 8 in. diameter circle does not exceed 2 in.

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

PART RB

If any of the above is not met, the pitted area must be repaired. There is no remaining life calculation for pits

Weld joint efficiency For corroded areas away from seams, the required thickness may be re-calculated using a joint efficiency of 1.0. This will help the evaluation, if the design was based on a joint efficiency less than 1.0

For the above, weld surface includes the lesser of 1 in. or 2 times thickness on either side of weld

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

PART RB

Ellipsoidal and torispherical heads Section VIII requires that formed heads be of uniform thickness based on the stresses in the knuckle.

This Code allows differentiating between the knuckle and the dome. The required thickness of the dome may be less. If the corroded area in entirely within the dome area, this can be very helpful

The dome is to be considered as that portion of the head falling within a circle with diameter equal to 80% of vessel diameter

For ellipsoidal heads, the equivalent spherical radius of the dome shall be K1D, in Section VIII

Adjustments to corrosion rate If the corrosion rate of a vessel changes, the new rate must be used to establish the next inspection date

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

GENERAL

API Recommended Practice 579 (API-579), entitled Fitness for Service was published in January of 2000. It is based on a great deal of work that was performed by the Material Properties Council (MPC) over many years.

It provides methods for evaluation of several kinds of flaws. Prior to publication of this document, every organization would perform flaw evaluation with their own rules.

This course provides an introduction to API-579 and presents some of its simple evaluation methods. Some of the more analytical methods, which require specialized knowledge of the subject matter, are not within the scope of this course.

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

GENERAL

The rules cover vessels, boilers, piping, tanks and other pressure equipment

API-579 becomes a legal document when referenced by an in-service inspection code such as API-510, API-570, or NBIC.

This document may be applied to equipment constructed to Section VIII vessels, Section I boilers, B-31 piping, API-620 and 650 tanks, and other recognized codes

The document has sections on different forms of flaw. Different levels of evaluation are allowed. Inspectors may do level 1 evaluations. Levels 2 and 3 must be performed by an engineer.

There are certain qualifications specified for the Inspector andthe Engineer

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

GENERAL

The document consists of the following: Section 1 Introduction Section 2 Fitness-For-Service Engineering assessment

procedure Section 3 Assessment of Equipment for Brittle Fracture Section 4 Assessment of General Metal Loss Section 5 Assessment of Local Metal Loss Section 6 Assessment of Pitting Corrosion Section 7 - Assessment of Blisters and laminations Section 8 Assessment of Weld misalignment and shell

Distortions Section 9 Assessment of Crack Like Flaws Section 10 Assessment for Components Operating in

creep range Section 11 Assessment of Fire Damage Appendices

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

FITNESS FOR SERVICE

Level 1 assessment: Intended to provide conservative screening criteria Requires minimum amount of inspection and

information May be performed by an Inspector or Engineer

Level 2 assessment: Intended to provide more detailed evaluation Produces more precise results Would be done by an experienced Engineer If result not acceptable, can resort to level 3

Level 3 assessment: Intended to provide the most detailed evaluation Produces most precise results Detailed inspection and information required Usually based on numerical techniques such as finite

element analysis To be performed by experienced engineering

specialist

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

INTRODUCTION

ASME Post Construction Committee (PCC) was formed in early 1995, to develop and maintain standards for maintenance of in-service vessels, including inspection rules, flaw evaluation rules, and repair/alteration procedures (flaw evaluation activities have been combined with those of API-579)

The documents will cover all pressure equipment, including pressure vessels, piping, boilers, and tanks

The published documents are not codes and have no legal standing. They become mandatory, when called in by inspection codes, such as NBIC and API-510

The inspection planning document, with extensive rules, will be published shortly

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

INTRODUCTION

A great deal of effort being spent to develop repair methods

The first document published by the PCC was the GUIDELINES FOR PRESSURE BOUNDARY BOLTED FLANGE JOINT ASSEMBLY, published in 2000

The above document applies to pressure boundary flanged joints with ring-type gaskets that are entirely within the bolt circle

These guidelines may be used to develop effective joint assembly procedures

Date: 24th ~ 27th October 2006 Organized By: EDS Solutions Co., Ltd. ~ED Knowledge Team~

WRC BULLETINS

Welding Research Council (WRC) is the parent organization of the Pressure Vessel Research Council (PVRC)

PVRC performs research and development work, for Code writing organizations. The results of PVRC work is published in WRC Bulletins

Bulletins 488, 489, and 490, published in early 2004, present the results of a long and extensive research project. They present damage mechanism in equipment in pulp and paper, refining, and power industries

The work was sponsored by API, National Board and a number of other organizations

PART 1INTRODUCTION TO NBIC AND API-510INTRODUTION TO OTHER DOCUMENTSINTRODUCTION TO OTHER DOCUMENTSPART RBPART RBPART RBPART RBPART RBPART RBGENERALGENERALGENERALFITNESS FOR SERVICEINTRODUCTIONINTRODUCTIONWRC BULLETINS