scholarly journals LARGE DIAMETER POLYETHYLENE SUBMARINE OUTFALLS

1984 ◽  
Vol 1 (19) ◽  
pp. 210
Author(s):  
L.A. Jackson
Keyword(s):  
High Density Polyethylene ◽  
State Of The Art ◽  
Large Diameter ◽  
City Council ◽  
High Density ◽  
Gold Coast ◽  
Steel Pipes ◽  
Concrete Pipes ◽  
Polyethylene Pipes ◽  
Navigation Channel

This paper presents the state of the art that has now evolved in Australia and shows the trend towards using high density polyethylene pipes for submarine conditions and the varying techniques and materials utilised. Prior to 1981 High Density Polyethylene (H.D.P.E.) was not produced in Australia in diameters larger than 630mm and even in the available sizes submarine outfalls were in the main constructed of mild steel or concrete pipes. In 1980 the Gold Coast City Council called tenders for the supply and installation of a 1500 metre, 1 metre diameter, outfall across the Southport Broadwater which is an active tidal estuary area. The proposed route crossed a main navigation channel and required trenching up to 8 metres into sand and sandstone. After consideration of the special requirements and high tender prices for conventional materials, Council constructed a temporary 400mm diameter H.D.P.E. outfall while the design of the permanent outfall was re-evaluated. The outfall was eventually constructed by day labour utilising a 1 metre diameter H.D.P.E. at a cost saving of approximately $1.5 million over the lowest tender price utilising steel pipes. Manufacturing facilities were imported into Australia for this job and now other large diameter submarine H.D.P.E. outfalls have been constructed in Australia and this material is now gaining acceptance.

Effect of flow forming on mechanical properties of high density polyethylene pipes

2015 ◽  
Vol 19 ◽  
pp. 155-162 ◽  
Author(s):  
Amin Abedini ◽  
Payam Rahimlou ◽  
Taghi Asiabi ◽  
Samrand Rash Ahmadi ◽  
Taher Azdast
Keyword(s):  
Mechanical Properties ◽  
High Density Polyethylene ◽  
High Density ◽  
Flow Forming ◽  
Polyethylene Pipes

scholarly journals MECHANICAL CHARACTERIZATION OF PA 12 AND HDPE PIPES BEFORE AND AFTER AGING IN WATER AT TWO DIFFERENT TEMPERATURES

2021 ◽  
Vol 9 (1) ◽  
pp. 248-256
Author(s):  
J.A. dos Santos ◽  
R.C. Tucunduva ◽  
J.R.M. D’Almeida
Keyword(s):  
High Density Polyethylene ◽  
Mechanical Performance ◽  
High Density ◽  
Effect Of Temperature ◽  
Polyamide 12 ◽  
Polyethylene Pipes ◽  
Before And After ◽  
Different Temperatures ◽  
Deterioration Process ◽  
Combined Action

Polymer pipes are being widely used by many industrial segments. Although not affected by corrosion, the mechanical performance of these pipes can be reduced due to exposure to temperature, UV radiation and by contact with various fluids. Depending on the deterioration process, embrittlement or plasticization may occur, and the service life of the pipe can be severely reduced. In this work, the combined action of temperature and water upon the mechanical performance of polyamide 12 and high-density polyethylene pipes is evaluated. Destructive and non-destructive techniques were used and the performance of both materials was compared. Both polymers were platicized by the effect of water. However, for high density polyethylene the effect of temperature was more relevant than for polyamide. This behavior was attributed to the dependence of the free volume with the markedly different glass transition temperature of the polymers and the temperatures of testing.

scholarly journals Studies and Research on the Behavior of Polyethylene when Electrofusion Welding Fittings to High Density Polyethylene Pipes

2021 ◽  
Vol 58 (1) ◽  
pp. 85-98
Author(s):  
Eugen Avrigean
Keyword(s):  
High Density Polyethylene ◽  
Welding Process ◽  
High Density ◽  
Polyethylene Pipes ◽  
The Way

This aim of this paper is to perform a study on the way the material of the fittings that can be welded through eletrofusion on polyethylene pipes withstands. The process is observed by means of the thermal and fast cameras. Also we intend to analyze the way the assembly consisting of the polyethylene fitting and pipe behaves during welding. The stresses caused by the welding process are observed, as well as the concurrent welding of the tapping tee and the branch saddle tee.

Crack Growth in High-Density Polyethylene Pipes

1984 ◽  
Vol 12 (6) ◽  
pp. 371 ◽  
Author(s):  
KA Peters ◽  
S Gebremedhin ◽  
RL Meltzer ◽  
M Bruce Vieth ◽  
PA Gradin ◽  
...  
Keyword(s):  
Crack Growth ◽  
High Density Polyethylene ◽  
High Density ◽  
Polyethylene Pipes

Behavior of High-Density Polyethylene Pipe with Shallow Cover

1998 ◽  
Vol 1624 (1) ◽  
pp. 214-224 ◽  
Author(s):  
B. M. Phares ◽  
T. J. Wipf ◽  
F. W. Klaiber ◽  
R. A. Lohnes
Keyword(s):  
High Density Polyethylene ◽  
Parallel Plate ◽  
Large Diameter ◽  
Field Tests ◽  
High Density ◽  
Concentrated Loads ◽  
Testing Program ◽  
Flexural Testing ◽  
Longitudinal Strength ◽  
Flexural Tests

In this investigation, a testing program was initiated to gain some understanding of the nature of high-density polyethylene (HDPE) as a structural material and as a buried structure. The testing program consisted of a series of parallel plate tests, a sequence of flexural tests, and field tests of buried pipes under varying backfill conditions. Parallel plate tests were conducted in accordance with ASTM D2412. The flexural testing consisted of applying two point loads to simply supported beam specimens. The field tests completed in this investigation were developed to study the response of large-diameter HDPE to concentrated loads under shallow cover. From the testing, it seems that in cases where high longitudinal stresses may be present (concentrated loads with shallow cover, uneven bedding, uplift, etc.) the pipeline designer should consider the longitudinal strength of HDPE pipes in addition to the circumferential and backfill properties. In addition, the designer must realize that when stresses exist in both directions, the Poisson’s ratio effect must be considered. This finding is supported by the longitudinal failure strains measured during the flexural tests and the field tests. In both types of tests, the pipes failed at approximately the same longitudinal strain level, approximately 1,300 microstrain. On the other hand, in the field tests, the pipes never reached the magnitude of strain associated with failure in the laboratory parallel plate tests.

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