OSHA 1910:applies to PV,Piping,tanks,PRD,fire protection system equipments etc
DAMAGE: THE OCCURRENCE OF A CHANGE FOR THE WORSE FLAW: DISCONTINUITY,IRREGULARITY OR DEFECT THAT IS DETECTED BY AN INSPECTION
This acceptance criterion is used in design codes. Elastic-Plastic analysis:
Based on quality of available information , assessment level and appropriate assumptions to provide an estimate safety factor for op until the next scheduled inspection
In service monitoring methods is one of the method whereby future damage or conditions leading to future damage can be assessed.
Safd = allowable stress for damaged material Cism = in-service margin SaT = allowable stress from the code at design temperature SaA = allowable stress of the original design code at ambient temperature
In 1990 a joint industry project was organized by materials properties council (MPC) concentrated the program on the development of technology for FFS and the culmination of this program was the development of API RP 579.
Sponsor s of the API RP 579 were Exxon, Shell, BP, Mobil, Chevron, Arco & Amoco
In 2000 API published API RP 579 for FFS assessment to evaluate flaws or damage in the in-service equipment.
Primarily it was intended to refining & petrochemical assets
In 2007 API joined forces with the ASME to produce an updated document with the designation API-759-1/ASME FFS-1
ASME & API codes & standards for pressurized equipment do not provide rules for the evaluation of deficiencies of in-service equipment.
API 510,570 ,653 & NB-23 do address the fact that equipment degrades while in service.
FFS ASSESSMENT PROCEDURES INTRODUCTION PITTING CORROSION LOCAL METAL LOSS GENERAL METAL LOSS BRITTLE FRACTURE PART 1 PART 2 PART 3 PART 4 PART 5 PART 6
PART 12 PART 11 PART 10 PART 9 PART 8 PART 7 PART 13 WELD MISALLIGNMETN & DISTORTION BLISTER & HIC/SOHIC DAMAGE DENT,GOUGE & DENT GOUGE COMBINATIONS LAMINATIONS FIRE DAMAGE HIGH TEMPERATURE OPRATION & CREEP CRACK LIKE FLAW
Damage or flaw during fabrication, material of construction, service and/or environmental conditions.
Overview of damage classes in this standard is shown in figure 2.1
STEP 2:APPLICABILITY & LIMITATIONS
Applicability & limitations for assessment are described for each part and a decision on whether to proceed with the assessment can be made.
STEP 3:DATA REQUIREMENTS
Equipment design data, maintenance & operational history, location of flaw from the weld seams & material properties.
A general data sheet is included in table 2.2
For MAWP calculations ,manufacturing drawings of vessel and tanks and piping isometrics with piping flexibility calculations are required.
DAMAGE CLASSES BRITTLE FRACTURE CORROSION/ EROSION CRACK LIKE FLAW FIRE DAMAGE CREEP DAMAGE MECHANICAL DAMAGE GENERAL METAL LOSS LOCAL METAL LOSS WELD MISALIGNMENT & SHELL DISTORTION DENT,GOUGE & LAMINATION PITTING
FFS assessment should be documented so that it can be repeated later.
Equipment design data , maintenance and past operational history , future operating and design conditions , calculation of the MAWP , RL , next inspection interval and any remediation or mitigation/monitoring for continued service.
Obtain records of fire incident & equipment information Assign the component to a HEZ Perform level I assessment Equipment is accepted per level I screening criteria YES NO Perform level II assessment NO Equipment acceptable per level II assessment YES Rerate equipment NO Perform rerate as per level II criteria YES NO
Equipment Acceptable per Level III assessment? Rerate equipment YES Remaining life acceptable Repair or Replace equipment Return the equipment To service NO Determine the Remaining life Perform level III assessment Perform rerate Per level III Criteria NO YES NO YES NO NO