Standard
Track updates
AS 4321:2025
[Current]AS 4321:2025 specifies requirements for factory-applied fusion-bonded medium-density polyethylene coating and lining of pipes and fittings, for protection against corrosion
Published: 16/05/2025
Pages: 41
Table of contents
Cited references
Content history
Table of contents
Header
About this publication
Preface
1 Scope
2 Normative references
3 Terms and definitions
4 Materials
4.1 General
4.2 Polyethylene coating (and lining) compound
4.2.1 Composition
4.2.2 Dispersion of additives
4.3 Polyethylene reinstatement compound
4.3.1 Composition
4.3.2 Dispersion of additives
5 Coating and lining application
5.1 Preparation of surface
5.2 Application
5.3 Cleaning of pipe and fitting ends
5.4 End treatment
6 Test requirements
6.1 Type test
6.1.1 General
6.1.2 Polyethylene coating (and lining) compound
6.1.2.1 General
6.1.2.2 Thermal stability
6.1.2.3 Water absorption
6.1.2.4 Penetration resistance
6.1.2.5 Tensile stress at yield
6.1.2.6 Environmental stress-cracking resistance
6.1.2.7 Density
6.1.2.8 Impact resistance
6.1.3 Polyethylene reinstatement compound
6.1.3.1 General
6.1.3.2 Water absorption
6.1.3.3 Adhesion to steel
6.1.3.4 Adhesion to polyethylene coating compound
6.2 Application process qualification
6.3 Production tests
6.3.1 General
6.3.2 Thickness
6.3.3 Continuity test
6.3.4 Bond strength
7 Reinstatement
7.1 General
7.2 Application of reinstatement
7.3 Reinstatement test requirements
8 Repairs
8.1 General
8.2 Repair limits
8.2.1 Coating repairs
8.2.2 Lining repairs
8.3 Repair test methods
9 Test frequency
10 Effect of FBPE lining on water quality
11 Storage, handling, transport and marking
11.1 Handling and storage of coated pipes and fittings
11.2 Transport of coated pipes and fittings
11.3 Marking
Appendix A
A.1 Scope
A.2 Relevance
A.3 Terms and definitions
A.4 Minimum sampling and testing frequency plan
A.4.1 General
A.4.2 Testing
A.4.3 Retesting
A.4.4 Rejection after retest
A.5 Type testing for re-evaluation
A.5.1 Change in material/compound
A.5.2 Required type tests
Appendix B
B.1 General
B.2 Information to be supplied by the purchaser
Appendix C
C.1 Scope
C.2 Principle
C.3 Apparatus
C.4 Preparation of test piece
C.5 Procedure
C.6 Test report
Appendix D
D.1 Scope
D.2 Principle
D.3 Apparatus
D.4 Preparation of test piece
D.5 Procedure
D.6 Test report
Appendix E
E.1 Scope
E.2 Principle
E.3 Apparatus
E.4 Preparation of test piece
E.5 Procedure
E.6 Test report
Appendix F
F.1 Scope
F.2 Principle
F.3 Apparatus
F.4 Preparation of test pieces
F.5 Conditioning
F.6 Procedure
F.7 Report
Appendix G
G.1 Scope
G.2 Principle
G.3 Apparatus
G.4 Reagent
G.5 Preparation of test pieces
G.6 Conditioning
G.7 Procedure
G.8 Report
Appendix H
H.1 Scope
H.2 Principle
H.3 Apparatus
H.4 Removal of sample from test pipe
H.5 Preparation of test specimens
H.6 Procedure
Appendix I
I.1 Scope
I.2 Principle
I.3 Preparation of coated test pipe
I.4 Procedure
I.5 Report
Appendix J
J.1 Scope
J.2 Principle
J.3 Apparatus
J.4 Preparation of test piece
J.5 Procedure
J.6 Test report
Appendix K
K.1 Scope
K.2 Principle
K.3 Apparatus
K.4 Preparation of test piece
K.5 Procedure
K.6 Test report
Appendix L
L.1 Scope
L.2 Principle
L.3 Apparatus
L.3.1 General equipment
L.3.2 Cathodic disbonding test cells
L.4 Preparation of test sample
L.5 Test procedure
L.6 Report
Appendix M
M.1 Scope
M.2 Apparatus
M.3 Voltage setting and calibration
M.4 Procedure
M.4.1 FBPE coated or lined pipes with exposed steel
M.4.2 FBPE coated pipes with no exposed steel but with a cement mortar lining
M.4.3 FBPE coated and lined pipe completely covered with FBPE
M.4.4 Testing
M.5 Report
Appendix N
N.1 Scope
N.2 Principle
N.3 Apparatus
N.4 Preparation of test piece
N.5 Test conditions
N.6 Procedure
N.7 Report
Cited references in this standard
[Current]
Metal finishing — Preparation and pretreatment of surfaces, Part 2: Power tool cleaning
[Current]
Metal finishing — Preparation and pretreatment of surfaces, Part 4: Abrasive blast cleaning of steel
[Current]
Site testing of protective coatings, Method 3: Determination of dry film thickness