api 6a-21 st edition hphtmay 2015 api 6a 21 st edition wg api subcommittee sc-6 discussions valves...

API 6A-21st Edition HPHTMay 2015

API 6A 21st Edition WG

API Subcommittee SC-6 DiscussionsValves and Wellhead Equipment

API 6A 21st Edition - HPHTMay 2015 2

Progress Since January Meeting

• Several TG meetings with focus on comment ballot release

• Worked to clarify document approach to HPHT for BSEE HPHT presentation

• A draft document including ordered PDF (90 pages) changes has been generated and circulated for a “comment-only” ballot. The draft contains only proposed technical & editorial changes but no reorganization of content


Work Teams/Captains

– Design / Jean Brunjes– Materials, Welding and Cladding / Sterling Lewis– Organization / Eric Wehner– Qualification / Tom Lambert– Quality / Mike Briggs

– Documentation Specialist / Jill Bell– Co-Chairs / Eric Wehner & David Zollo

API 6A 21st Edition - HPHTMay 2015

Key Items addressed

• Definition of a manufacturer requirements added• Tied pressure / NACE limitations to PSL’s• Annex M reworked to move requirements to main

body of the document. Annex M is normative.• PSL 4 requirements changed to align with potential

HPHT requirements (no welding requirement removed)

• PSL 3 – heat lot traceability requirement added• Welding hardness survey requirements removed to

default to NACE• Minimum clad thickness requirement added• Better definition of design criteria when referring to

clad thickness


Key Items addressed

• Moved repair Annex J to 6AR• Removed Annex H – Tools (TR needed)• Design rules moved to 6X• Defined performance and product testing for

bleeder plugs• Revised Annex L and added 4” HPVR• Added language to reference 20 series

specification requirements (castings, bolting-BSL-1 minimum requirement)

• Eliminated PR1 in Annex F • Annex C stud length replaced by AWHEM TR


Key Items addressed

• Corrected valve bore metric conversion for one set of drifts (mtric/Imperial)

• Clarified Tree Cap dimensions by modifying tables in Annex


Plan forward

• Send current draft out as comment only ballot• Start reorganization work / Annex Work

– Annex J replace by 6AR (Circulate Draft Prepared by Ed)– Annex H replace with TR (Tools)– Annex I & O - Eliminated

• Resolve comments• Reorganize the entire document per Eric’s plan

– General– Defined Equipment (Design excluded)– Manufacturer designed equipment

• Address HPHT• Have final document ready for ballot by June 2016


Thoughts on HPHT Approach

API Subcommittee SC-6 DiscussionsValves and Wellhead Equipment


Includes 2,000 to 20,000 psi working pressure equipment PSL 1,2,3,3G & 4 All PSL’s available for all pressure ratings Sour and non-sour service classes for all pressure ratings Charpy V-notch impact requirements 20 joules (15 ft-lbf) for all PSL

Levels Hydrostatic testing to 1.5 times working pressure for 5KSI thru 20KSI

equipment & 2 times working pressure for 2&3K Design requirements – self contained: Per ASME BPVC Section VIII Div

2:2004 with some modifications External loading (bending/axial) not explicitly addressed but must be

considered when designing casing/tubing heads, tubing-head adapters,OEC’s, tools for running,retrieving, clean-out and testing

Current high temperature derating requirements contained in informative Annex G

Use of QTC’s for material properties for production components Design validation by means of product testing is an informative

requirement

Scope of 6A 20th Edition Document(Current Code)


API Spec 6A

API TR 6AF

API TR 6AF2

API TR 6AF1

Existing Supporting Technical Reports Referenced in API 6A

API TR 6AF1, Technical Report on Temperature Derating on API Flanges

Under Combination of Loading

API TR 6AF, Technical Report on Capabilities of

API Flanges Under Combinations of Load

API TR 6AF2, Technical Report on Capabilities of API Integral Flanges

Under Combination of Loading —Phase II


Annexes

Stud Sizing

Purchasing

Heat Treat Qualification

Elevated Temperatu

reUnit Conversion

Flange Bolt

Torque

Special Equipment

Monogramming

Validation General

Requirements

Manufacturer DesignEquipmen

t

Legacy

Equipment

API 6A 21st Edition Reorganization Proposal


6A HPHTApproach

Materials

Design Validation

QC

API 21st Edition / HPHT Alignment


6A HPHTApproach

Materials

Design Validation

QC



• Target PSL 4 for HPHT - Bodies and Bonnets (Pressure Containing Equipment)– Remove weld repair restriction to make PSL 4 usable– Require prolongation or sacrificial part for material property tests– Test location shall be at T/4 of prolongation or thickest section of sacrificial

part – Testing per heat treat batch– Separate quench loads not allowed with just single prolongation

• BSL 3 per 20E bolting requirement (Closure Bolting)• Stud/nut hardness matching• 20H HSL level 2 or 3 Furnace Calibration requirement

– 2 = tighter calibration and survey requirements– 3 = full AMS 2750 compliance

• AWHEM material derating factors normative in the absence of actual test data

• High strength nickel alloy requirements in conformance with API 6A-CRA

• Sour service compliance per NACE MR0175 mandatory to eliminate fouling situations where a “sweet” service well sours beyond NACE limits

Materials & QC Changes


6A HPHTApproach

Materials

Design Validation

QC



Design (≤ 15K Per Current 17TR8)

API 6XASME

SECTION VIII, DIV 2

Elastic-Perfectly

Plastic

≤ 15K17TR8

Assess 17TR8 Logic

True Stress-True StrainLinear-Elastic

> 15K≤20K17TR8

For select failure mode only (unusual)

ASME Section VIII Div2 with API allowable

stressesASME Section VIII Div2 with API material properties


Design (>15K ≤20K Per Current 17TR8)


API 6X

ASME SECTION VIII,

DIV 2

Elastic-Perfectly Plastic

> 15K≤20KPROPOSED 6A

≤ 15K17TR8

Assess 17TR8 Logic

True Stress-True Strain

Linear-Elastic

FatigueSensitive

S-N ScreeningYes

ValidationNo Validation

Design

PR4PR2/PR3

Add Wall ThicknessCaveat Statement to 6A/6X. Cannot

Average Stresses inThick Wall

Assess legacy 20K

Flanges with newer

methods


Fatigue screening requirements per 17TR8?

• For fatigue screening, we have legacy designs that are justified based on documented field history and successful performance. This is permitted under ASME BPVC Section 8, Div. 2 Paragraph 5.5.2.

• “Provisions of paragraph 5.5.2.2, Experience with comparable equipment operating under similar conditions.”

• For designs where equivalency to a legacy design cannot be

established, a fatigue screening analysis would have to be performed for each application to determine the necessity as well as the method to be used for fatigue analysis. Using the SN method, a screening can be conducted on high stress concentration areas to assess fatigue life and necessity to do a more exhaustive fatigue analysis.


6A HPHTApproach

Materials

Design Validation

QC



• Currently validation via prototype testing is not a normative requirement (Annex F is Informative)

• 17TR8 dictates that a FMEA (failure modes and effects analysis) be conducted in order to develop an appropriate validation program

• Guidance for PR3 & PR4 testing are included in 17TR8

Validation


PR2As described in API 6A Annex F

PR3The validation testing requirements of PR2 plus the addition of the appropriate tests below:

Elevated Temperature Performance Testing

Mating component validation

Additional thermal cycling

Endurance cycling testing

PR4The validation testing requirements of PR3 plus the additional procedures associated with validating the design verification process of with respect to fatigue sensitive components through one of the following methods:

strain-gauging program of a representative specimen or component comparison (FEA) results

Component fatigue testing


6A HPHTApproach

Materials

Design Validation

QC



Workgroup Proposal

Per 6X Limit Analysis

Global Plastic Collapse per API STD 6X

Tri-axial Stress

(Div 2:5.3.2)

Ratcheting(Div 2: 5.5.7)

OR

Analysis approach to 20K - Elastic Perfectly Plastic w/Large StrainPotential API TR “6AF3” This is (Limit analysis in 6X with large displacement) (Ref. API Std 6X Clause 6.2 We would take a different approach from the ASME methods and support our approach via some comparative analysis of existing 20K API flanges • Leakage Criteria

• Separation threshold

• Flange Stresses• 1.5 x Working Pressure

• Bolting Stresses

• 83% of yield w/temperature derating?

HPHT Design Flow-Chart From 17TR8Figure 1

Proposal Per 5/11/15 meeting with Paul Bunch, John Fowler, Nigel McKie, David Zollo

api 6a-21 st edition hphtmay 2015 api 6a 21 st edition wg api subcommittee sc-6 discussions valves...

Documents

annex slide

edition hphtmay

edition hphtmay

psls annex

revised annex

edition wg api subcommittee

pressure equipment psl

ed annex h