Peter Tuft AS Launch, February AS PENETRATION RESISTANCE
Peter Tuft - Penetration Resistance AS Launch, February Why Penetration Resistance?
Peter Tuft - Penetration Resistance AS Launch, February It really happens Acknowledgements: Rob Moore & Caltex
Peter Tuft - Penetration Resistance AS Launch, February General Requirements Penetration resistance is one form of physical protection Mandatory in developed areas (T1, T2, S & I); see separate Clause 4.7 May be used in R1 & R2 areas if required by SMS Especially near isolated buildings (ie. within radiation contours) From Clauses &
Peter Tuft - Penetration Resistance AS Launch, February Methods Calculate using Appendix M Expected to be usual approach Physical testing Beneficial for some projects in high consequence areas Comparison with previous physical tests Must be sufficiently similar From Clause
Peter Tuft - Penetration Resistance AS Launch, February Calculation Objectives Determine minimum size of excavator to puncture pipe For both general purpose and pointed teeth Determine likely puncture hole size, and hence failure mode Rupture if hole ≥ critical defect Leak if hole < critical defect No penetration Should do calcs even if penetration resistance is not adopted as physical control Useful reference data for SMS From Clause
Peter Tuft - Penetration Resistance AS Launch, February Define the Threat Equipment type Usually an excavator Equipment size (tonnes) Penetrator (tooth) type General purpose (chisel shaped) Penetration (single sharper point) “Tiger tooth” (twin sharp points) Penetrator dimensions From Clause
Peter Tuft - Penetration Resistance AS Launch, February Calculation Principles No penetration if resistance > force R P > B F R P = force required to penetrate pipe (for given pipe parameter and tooth dimensions) F = nominal force applied by machine B = multi-purpose correction factor From Appendix M2
Peter Tuft - Penetration Resistance AS Launch, February Pipe Resistance, R P Based on extensive APIA-sponsored research Excellent correlation between tests, FEA and equation: Equation M3
Peter Tuft - Penetration Resistance AS Launch, February Excavator Force, F Also based on APIA-sponsored research Reasonable correlation between excavator mass and bucket force: Equation M4
Peter Tuft - Penetration Resistance AS Launch, February Factor B Multipurpose Bucket force multiplier, empirical experience, safety factor Largely based on Australian field trials Range from 0.75 to 1.3 Original research suggested 1.8 to 2.0 Theoretically sound, but not achieved in practice due to limited reaction force May change as further research progresses
Peter Tuft - Penetration Resistance AS Launch, February B Values CircumstancesB Where WT not governed by penetration resistance <0.75 Adequate resistance to typical excavator, but puncture possible if aggressive 0.75 Reasonable compliance with “No Puncture”1.0 Where penetration must never occur, in some high consequence areas ≥1.3
Peter Tuft - Penetration Resistance AS Launch, February Field Trials
Peter Tuft - Penetration Resistance AS Launch, February … in Action Acknowledgements: Phil Colvin & Alinta
Peter Tuft - Penetration Resistance AS Launch, February … and the Results
Peter Tuft - Penetration Resistance AS Launch, February
Peter Tuft - Penetration Resistance AS Launch, February The Design Scenario Roma - Brisbane duplication DN 400, 450 km Land use ranging from rural to suburban 15.3 MPa, 10.2 MPa from city gate station Assume X80 pipe SMYS = 552 MPa, UTS ≥ 621 MPa
Peter Tuft - Penetration Resistance AS Launch, February The Design Problem Check penetration resistance for: LocationWTExcavatorTeeth Rural roadside4.8 mm20 t Gen purpose (76 x 13 mm) Suburban8.4 mm30 t Tiger (20 x 12 mm) Tooth dimensions from Table M3
Peter Tuft - Penetration Resistance AS Launch, February Rural Location 4.8 mm WT, 20 t excavator, GP teeth R P (pipe resistance)275 kN F bucket 131 kN B (adequate resistance)0.75 B F98 kN R P >> B F Resistance >> machine force No penetration 4.8 mm WT OK for the identified threat
Peter Tuft - Penetration Resistance AS Launch, February Suburban Location 8.4 mm WT, 30 t excavator, tiger teeth R P (pipe resistance)181 kN F bucket 184 kN B (reasonable ‘No Puncture’)1.0 B F184 kN R P ≈ B F Resistance ≈ machine force No penetration, just 8.4 mm WT minimum acceptable for the identified threat
Peter Tuft - Penetration Resistance AS Launch, February Worth 1000 Words …
Peter Tuft AS Launch, February Questions?