Basic knowledge of pipeline materials

What is a pipeline?

In the most basic terms, pipelines are a system of connected pipes used for transporting liquids, gases, and even solid materials over long distances.

20230519224450 32487 - Basic knowledge of pipeline materials

Why Pipeline Material Matters?

Picking the right pipeline material is not a trivial decision.
Safety Factors
Different pipeline materials have different resilience levels to pressure, temperature, and chemical exposure. Ensuring safety means choosing the material that can withstand the unique challenges of the substance it carries.
Environmental Considerations
Pipeline material choice also has significant environmental implications. A poorly chosen material could lead to leaks, causing environmental damage.

Basic Materials used in Pipelines

(1) Classification of metal pipe materials

The classification of metal pipe materials by materials is
shown in Table 1.

Table.1 Classification of metal pipe materials

Big classification

In
the classification

Subclassification

Example
of pipe name



Metal pipe

Iron
pipe

Cast-iron
pipe

Bearing
cast iron pipe (sand-type centrifugal cast iron pipe, continuous cast iron
pipe)


Carbon
steel pipe

B3F
Welded steel pipe, #10, #20 steel seamless steel pipe, high quality carbon
steel seamless steel pipe

Low
alloy steel pipe

The
16Mn seamless steel pipe

Alloy
pipe

Heat-resistant
steel pipe (15CrMo, etc.)

Stainless
steel pipe

Austenitic
stainless steel pipe (0Cr18Ni9, etc.)

Nonferrous
metal pipe

Copper
and copper alloy pipes

Pull
and squeeze brass pipe, copper pipe, and copper-nickel alloy (Monel, etc.)

Lead
pipe

Lead
pipe, lead-antimony alloy pipe

Aluminum
pipe

Cold-pulled
aluminum and aluminum alloy round pipe, hot extruded aluminum and aluminum
alloy round pipe

Titanium
pipe

 Titanium pipe and titanium alloy pipe
(Ti-2A1-1.5Mn, Ti-6AL-6V-2Sn-0.5Cu-0.5Fe)

(2) Classification of non-metallic pipes and lining pipe
materials

The classification of non-metallic pipes and lining pipe
materials by materials is shown in Table 2.

Table.2
Classification of non-metallic pipes and lining pipe materials

Big classification

Subclassification

Example
of pipe name


Non-metallic pipe

Rubber
pipe

Gas
hose, water suction hose, oil hose, oil suction hose, steam hose

Plastic
pipe

Phenolic
plastic pipes, acid-resistant phenolic plastic pipes, hard polyvinyl chloride
pipes, high and low density ethylene pipes, polypropylene pipes,
polytetrafluoroethylene pipes, ABS pipes, PVC / FRP composite pipes, high
pressure polyethylene pipes

Asbestos
cement pipe

 

Graphite
pipe

Resbon
pipe

Glass
pipe ceramic pipe

Chemical,
ceramic pipe (acid-resistant, acid-resistant, industrial porcelain pipe)

Glass-reinforced
plastic pipe

Poly
FRP pipe, epoxy FRP pipe, phenolic FRP pipe, furan FRP pipe

Liner
pipe

 

 Rubber lining pipe, steel-plastic composite
pipe, coated plastic steel pipe

(3) Comparison Table of Common Pipeline Materials

The comparison of commonly used metal pipeline materials
is shown in Table 3.

Table.3
Control table of common metal pipe materials

Steel grade

Chinese
Industrial Standards GB

The
American Standard, ASTM

The
German standard, the DIN

The
Japanese Standard, JIS

 

Standard

Steel
pipe

Steel
pipe

Steel
products

Steel
pipe

Steel
pipe

 



Carbon
white

steel

GB/T8163GB9948

#10

A53-A

A105

1629-st37

STPG370

 

GB/T8163GB9948

#20

A53-B

A105

1629–st48.4

STPG410

 

GB/T8163GB9948

#20

A106-B

A105

17175–st45.8

STPT410

 

 

 

A106-C

STPT480

 

GB5130

20G

A106-B

17155–st45.8Ⅲ

STS410

 

GB6479

16Mn

17175–17Mn4

STS480

 

GB6479

#10

A105-A

A105

17175–st35.8

STPT370

 

Alloy
steel

GB9948GB6479GB5130

12CrMo

A335-P2

A182-F2

17175–15Mo3

STPA20

 

 

15CrMo

A335-P12

A182-F12

17175–13CrMo44

STPAA22

 

 

 

A335-P11

A182-F11

STPAA23

 

GB6479GB5130

12Cr2Mo

A335-P22

A182-F22

17175–10CrMo910

STPA24

 

 

 

 

A335-P9

A182-9

STPA26

 

Low-temperature
steel

GB/T8163GB6479

16Mn

A333-Gr1,6

A350-LF2

17173–TTSt35N

STPL380

 

No

rust

steel

GB/T14976

0Cr18Ni9

A312-TP304

A182-F304

17458–X5CrNi1810

SUS304TP

 

 

 

A312-TP304H

A182-F304H

SUS304HTP

 

GB/T14976

00Cr19Ni10

A312-TP304L

A182-F304L

17458–X2CrNi1911

SUS304LTP

 

GB/T14976


0Cr17Ni12Mo2

A312-TP316

A182-F316

17458X5CrNiMo1712217458X2CrNiMo17132

SUS316TP

 

 

 

A312-TP316H

A182-F316H

SUS316HTP

 

GB/T14976

00Cr17Ni14Mo2

A312-TP316L

A182-F316L

SUS316LTP

 

GB13296GB/T14976

0Cr18Ni10Ti

A312-TP321

A182-F321

17458

SUS321TP

 

 

 

A312-TP321H

A182-F321H

SUS321HTP

 

 

0Cr18Ni11Nb

A312-TP347H

A182-F347H

SUS347HTP

 

GB/T14976

0Cr19Ni13Mo3

A312-TP317

 

17458X5CrNiMo17133

SUS317TP

 

00Cr19Ni13Mo3

A312-TP317L

 

17458X2CrNiMo18143

 SUS317LTP

 

Note:

  • ① This
    reference table is prepared based on chemical composition and mechanical
    properties having one approximation or one approximation and another basic
    approximation, and the same steel type can be replaced by each other.
  • ② When
    there are special requirements, fashion should be a further detailed comparison
    and determine whether it can be replaced.

(4) Heat
treatment of common metal pipe materials

1. The
heat treatment methods of steel mainly include annealing and regular ignition,
quenching and tempering, quality adjustment, solid solution treatment, etc.

1)
Annealing and ignition

Heat the steel deviated from the equilibrium
state to the appropriate temperature, keep it warm for some time, and then cool
slowly (usually with the furnace) to obtain a heat treatment process close to
the equilibrium state tissue is called annealing. According to the purpose and
requirements of the treatment, the common annealing of steel can be divided
into complete annealing (recrystallization annealing), recrystallization
annealing, and stress elimination annealing.

Complete annealing is a complete customization
of iron-carbon alloy (heated to Ac3 above 20-30℃) and then slowly cooled to
obtain near-equilibrium tissue. Complete annealing is suitable for treating
sub-common and medium alloy steel to improve the mechanical properties of steel
cast iron or hot profiles. Because the heating temperature exceeds the above
critical point, the tissue is completely recrystallized, which can refine the
grain, uniform organization, reduce hardness, fully eliminate internal stress,
and other purposes.

Recrystallization annealing is to heat the
deformed metal above the recrystallization temperature (between 600℃-Ac1), and
maintain an appropriate time, so that the elongated and broken grains by cold
processing can nucleate and grow into normal grains, becoming a new stable
tissue without internal stress, so that the physical and mechanical properties
of steel can restored. For the steel of continuous cold processing many times,
due to the increased processing time, the increasing hardness, and the
declining plasticity, we must arrange a recrystallization annealing between the
two processing to soften it so that the steel can be further processed. This
annealing is also called softening annealing or intermediate annealing.

Eliminating stress annealing is to remove the
heat treatment process to remove the residual stress caused by plastic
deformation processing, welding, and other reasons in the casting, and the
heating temperature of stress annealing is lower than steel’s recrystallization
temperature.

Normal heat is a heat treatment process for
heating the steel to Ac3 (or Acm) above 30℃-50℃and cooling in the air after
heat preservation to obtain the bead body type tissue. It is mainly used to
refine steel grains, improve the tissue and improve its mechanical properties.

The
difference between normalizing and annealing is that the cooling speed of
normalizing is slightly faster, the tissue obtained is thinner than annealing,
and the comprehensive mechanical properties are improved.

2)
Quenching and tempering

Quenching is a heat treatment process in which
the steel is heated to 30℃ above Ac3 (sub-steel) or Ac1 (over-steel) above 30℃-50℃,
then cooled faster than the critical cooling rate. Quenching is generally to
obtain martensite tissue and strengthen the steel; quenching martensite is a
solid carbon solution in α-Fe.

Refire
is a process of heating steel to a certain temperature below Ac 1 and cooling
it in the air after insulation. The ailing is often used as a second heat
treatment after steel quenching to improve quenching organization. Refire is
also often used to eliminate steel’s deformation processing or residual welding
stress. According to the different purposes of steel used, the heating
temperature when tempering is also different. Regaling can be divided into low
temperature, moderate and high-temperature tempering.

3)
Quality adjustment

The heat
treatment process of quenching and high-temperature tempering is usually called
quenching and tempering. The tempered sorbate structure obtained after
quenching and tempering can enable the steel to achieve comprehensive
mechanical properties that match strength and toughness well.

4) Solid
solution treatment

Solid solution treatment is a heat treatment
process of heating the alloy to the high-temperature single-phase zone and
making rapid cooling to dissolve the excess phase into the solid solution to
obtain the oversaturated solid solution. The purpose is to improve the metal’s
plasticity and toughness and prepare the conditions for further
precipitation-hardening heat treatment.

For
non-ultra-low carbon austenitic stainless steel, the excess carbon can be
consolidated in austenite by solid solution treatment to eliminate the
sensitivity of intercrystalline corrosion general; the stainless steel is
usually heated to 1000℃ -1120℃and insulated by 1-2 minutes per millimeter, and
then chilled, so that the excess carbon is too late to migrate to the grain
boundary, to achieve the purpose of eliminating the grain boundary poor chromium.
After the solid solution treatment, the steel should still prevent the heating
at the sensitization temperature, otherwise, the chromium carbide will
re-precipitate along the grain boundary.

2. Common metal pipe materials used in heat treatment state

See
Table 4 for the heat treatment status of commonly used metal pipe materials.

Table.4 Commonly
used metal pipe materials use heat treatment state

Material trademark

As-heat-treated

Material trademark

As-heat-treated

Q-235

Normalization

15CrMo

Positive fire + tempering or the quality
adjustment

#20

Normalization

1Cr5Mo

Positive fire + tempering or the quality
adjustment

16Mn

Normalization

35CrMoA

tempering

12CrMo

Positive fire + tempering or the quality adjustment

0Cr18Ni9

Solid soluble

(5) The common corrosion environment in the process of
petrochemical production

1. Metal material and environmental combination that can
produce stress corrosion and rupture

  • (1) For carbon steel and low alloy steel, the medium is
    the alkali solution, nitrate solution, anhydrous liquid ammonia, wet hydrogen
    sulfide, acetic acid, etc.;
  • (2) For austenitic stainless steel, the medium is chloride
    ion, chloride + steam, hydrogen sulfide, lye, etc.;
  • (3) For molybdenum stainless steel containing austenite,
    the medium is lye, chloride aqueous solution, aqueous sulfuric acid + copper
    sulfate solution, etc.;
  • (4) For brass, the medium is ammonia gas and solution,
    ferric chloride, wet sulfur dioxide, etc.;
  • (5) For titanium, the medium has methanol or ethanol
    containing hydrochloric acid, molten sodium chloride, etc.;
  • (6) For aluminum, the media are wet hydrogen sulfide,
    hydrogen-containing hydrogen sulfide, seawater, etc.

The engineering measures to prevent material stress and
corrosion cracking include the following aspects:

  • One is to reduce the stress level, avoid or reduce the
    local stress concentration, eliminate the processing residual stress and
    welding residual stress;
  • The second is to
    control the sensitive environment, such as: adding corrosion inhibition and
    extrusion, improving the pH value of the medium, using electrochemical
    protection and other measures;
  • The third is the correct material selection to avoid the
    environmental combination of stress corrosion cracking materials.

2. Intercrystalline corrosion of austenitic stainless
steel

Austenitic stainless steel in the welding, the weld on
both sides of the 2-3mm can be heated to 400-910℃; this is the so-called
intercrystalline corrosion sensitization area. The chromium and carbon of the
grain boundary in this region settle with Cr23C6 from the solid solution. The
mobility of chromium is slow and it is not easy to diffuse from the inside to
the crystal boundary, so the grain boundary forms a chromium-poor zone. The
chromium content in steel must be more than 11% to have good corrosion
resistance, the chromium poor area can be reduced to 11% level, in a certain
corrosion solution will form ” chromium carbide (cathode) -chromium poor)
area (cathode) battery, so that the grain boundary chromium poor area
corrosion.

3. Engineering measures to prevent the intercrystalline
corrosion of austenitic stainless steel mainly include:

  • (1) Solidable heat treatment;
  • (2) Reduce the carbon content in stainless steel, and
    reduce the carbon content to less than 0.03%;
  • (3) Austenitic stainless steel with stable elements
    (mainly titanium and niobium) is used.

4. Constitute a wet hydrogen sulfide stress corrosion
environment

1) When the medium contains hydrogen sulfide and meets one
of the following conditions, it constitutes a wet hydrogen sulfide stress
corrosion environment:

  • (1) The partial pressure of hydrogen sulfide in the medium
    that is greater than or equal to 0.000345 MPa;
  • (2) the medium contains liquid water or the operating
    temperature is under the dew point;
  • (3) The medium pH is less than 6, but the pH can be
    greater than 7 when the medium contains cyanide.

2) When the medium constitutes the environmental
conditions of wet hydrogen sulfide stress corrosion cracking, the selected
materials shall meet the following requirements;

  • (1) The yield strength specified in the material standard
    shall be less than or equal to 355MPa;
  • (2) The measured tensile strength of the material should
    be less than or equal to 650MPa;
  • (3) The use state of the material should be ignition,
    ignition, annealing or adjustment;
  • (4) Carbon equivalent limit: for carbon steel and carbon
    manganese steel should be less than or equal to 0.4, for low alloy steel should
    be less than or equal to 0.45;
  • (5) Hardness limit: whether on the material body or weld
    and thermal influence area, the hardness shall be less than or equal to HB 200;
  • (6) Stress heat removal treatment or other equivalent heat
    treatment shall be conducted after welding.

5. Constitute a liquid ammonia stress corrosion cracking
environment

1) When the medium is liquid ammonia and meets one of the
following conditions, it constitutes a liquid ammonia stress corrosion
environment:

  • (1) The medium is liquid ammonia, the water content is
    less than or equal to 0.2% (wt), and may be contaminated by air (oxygen or
    carbon dioxide);
  • (2) The medium operating temperature is higher than-5℃.

2) When the medium constitutes the environmental
conditions of liquid ammonia stress corrosion cracking, the applied materials
shall meet the following requirements:

  • (1) The yield strength specified in the material standard
    shall be less than or equal to 355MPa;
  • (2) The measured tensile strength of the material should
    be less than or equal to 650 MPa;
  • (3) The use state of the material should be ignition,
    ignition, annealing or adjustment;
  • (4) Carbon equivalent limit: for carbon steel and carbon
    fierce steel should be less than or equal to 0.4, for low alloy steel should be
    less than or equal to 0.45;
  • (5) Hardness limit: whether on the material body or to the
    weld and the thermal influence area, the hardness shall be less than or equal
    to HB 185;
  • (6) Stress heat removal treatment or other equivalent heat
    treatment shall be conducted after welding.

6. Stress and corrosion conditions of caustic soda and
alkali liquor pipeline

Under certain conditions, caustic soda pipes can cause stress corrosion cracking (alkali embrittlement) of carbon steel materials. Factors affecting stress corrosion cracking of carbon steel include alkali concentration, operating temperature and residual stress in materials.

In general, the concentration (wt) and the wt) exceeds the
NaOH. As shown in Table 5.

Table.5

Concentration of NaOH (wt)%

5

10

15

20

30

40

50

60

Service
temperature ℃

85

76

70

65

54

48

43

40

Nickel-containing alloy shall be considered when NaOH
concentration (wt) and temperature exceed the following below. As shown in
Table 6.

Table.6

Concentration of
NaOH (wt)%

10

20

30

40

50

Service temperature ℃

105

110

97

82

77

7. Hydrogen
embrittlement and hydrogen corrosion

(1) Hydrogen brittle:
under high temperature and high pressure molecular hydrogen partial
decomposition into atomic hydrogen, or hydrogen in the wet corrosion
environment after electrochemical reaction to generate hydrogen atoms, the
hydrogen atoms into the steel interior, reduce steel atoms between atoms, cause
steel elongation, cross section shrinkage reduced, strength is reduced, this
kind of phenomenon is called hydrogen brittle.

(2) Hydrogen
corrosion: when steel contacts with high temperature and high pressure hydrogen
for a long time, hydrogen atoms or hydrogen molecules will react with carbide
(carburizing body) in steel to form methane (Fe
3C2 + 2H23Fe + CH4). When the
chemical reaction occurs on the surface of steel, it is called surface
decarbonization; when occurring in steel, it is called internal
decarbonization. Internal decarbonization and external decarbonization are
collectively referred to as hydrogen corrosion. For the internal
decarbonization of steel, because the methane gas can not spread out from the
steel, and the accumulation of local high pressure between the grains,
resulting in stress concentration, and then make the steel produce micro cracks
or bubbles, resulting in the decline of the strength and toughness of steel,
that is, the steel becomes brittle.

Hydrogen embrittlement is reversible; hydrogen
corrosion is permanent and irreversible.

The measures to
prevent hydrogen embrittlement in the project include: avoiding the
temperature-sensitive area, selecting materials with low strength, and reducing
the stress level of metal components.

(6) The selection of
pipeline materials

1. Material selection
should pay attention to at low temperature

(1) For carbon steel,
low alloy steel, medium alloy steel and high alloy ferrite steel, the lower
limit of the service temperature of steel is higher than-20℃. When the design
temperature is lower than or equal to-20℃, the summer ratio (type V-gap) low
temperature impact test shall be conducted according to the design provisions
of the low temperature pipeline. The low temperature shock test temperature
shall be below or equal to the minimum design temperature of the compression
element. However, the impact test shall be exempted for those who meet the
following conditions:

① The use temperature
is higher than-45℃, and not lower than the lower limit of the use temperature
specified in the specification, at the same time, the thickness of the material
cannot prepare 5 mm thick sample;

② In addition to
steel and bolt materials with lower limit of tensile strength greater than
540 MPa, the materials used are injected under low temperature and low stress
condition, if the design temperature is 50℃, higher than-20℃.

Note: Low temperature low stress condition
refers to the condition that although the design temperature of the compression
element is lower than-20℃, the film stress is less than or equal to one sixth
of the standard normal temperature yield strength of the steel, and not greater
than 50 MPa.

(2) For austenitic
stainless steel, the lower temperature limit of steel is higher than-196℃. When
the design temperature is lower than or equal to-196℃, the summer ratio (type
V-notch) low temperature impact test shall be conducted according to the design
provisions of the low temperature pipeline. However, if the carbon content of
the material is greater than 0.1% and the design temperature is lower than-20℃,
the low-temperature impact toughness test shall be conducted even if the design
temperature is not lower than-196℃.

2. Under the high
temperature material selection should pay attention to the problem

  • (1) When carbon
    steel, pure nickel steel, carbon manganese steel, manganese vanadium steel and
    carbon silicon steel are used above 425℃ for a long time, the possibility of
    its carbide is converted into graphite, resulting in a decrease in strength.
    These materials should be avoided when the expected operating conditions are
    such.
  • (2) When carbon
    molybdenum steel, manganese molybdenum vanadium steel and chromium vanadium
    steel are used for a long time, the carbide may be converted into graphite,
    resulting in a decrease in strength. These materials should be avoided when the
    expected operating conditions are such.
  • (3) When the chromium
    molybdenum alloy steel and the chromium molybdenum vanadium alloy steel are
    used in the temperature range of 400℃ -550℃ for a long time, it may cause
    tempering brittleness. If this use situation cannot be avoided in the project,
    appropriate protective (preventive) measures should be put forward.
  • (4) Ferite stainless
    steel is used at a temperature above 371℃, will appear brittle at room
    temperature. These materials should be avoided when the expected operating
    conditions are such.
  • (5) Feriron and
    martensitic stainless steel containing more than 12% chromium are used in the
    temperature range of 400℃ -550℃ for a long time, it may produce 475℃ brittle
    problems. These materials should be avoided when the expected operating
    conditions are such.
  • (6) High chromium
    stainless steel containing chromium more than 16% and high chromium nickel
    stainless steel containing chromium more than 18% may produce σ phase brittle
    problems when used in the temperature range of 540℃ -900℃. In this case, the
    ferroite content in the material should not exceed 8%.
  • (7) Generally,
    austenitic stainless steel will produce the sensitivity of intercrystalline
    corrosion when the temperature range is 427℃ -871℃. In this case, the material
    should be avoided in a medium environment that can cause intercrystalline
    corrosion, or using stable or ultra-low carbon stainless steel materials.
  • (8) Austenitic
    stainless steel and some low melting point metals such as: aluminum, antimony,
    bismuth, cadmium, gallium, lead, manganese, zinc and its compounds at high
    temperature (higher than the melting point temperature of these low melting
    point metals) contact, will produce the sensitivity of intercrystalline
    destruction. This environment should be avoided in the project.
  • (9) For austenitic
    stainless steel materials, when the use of temperature is greater than 525℃,
    should consider the use of high carbon (carbon content is more than 0.04%)
    stainless steel. If the carbon content is too low, the steel strength will
    decrease significantly.
  • (10). For carbon
    steel-austenitic stainless steel composite material, with a temperature greater
    than 400℃. These materials should be avoided when the expected operating
    conditions are such.
  • (11) When titanium
    and titanium alloy is used at the temperature above 316℃, there is a
    possibility of quality reduction. These materials should be avoided when the
    expected operating conditions are such.
  • (12) When the
    materials used are used above the creep temperature for a long time, attention
    should be paid to some adverse effects of creep, including excessive
    deformation of pipe components, excessive displacement of pipe nodes and even
    denaturation of materials; the sensitive effects of pipe components, such as
    bolts, can not be ignored.
  • (13) Materials that
    improve their performance through heat treatment. If the material is used at a
    temperature higher than the tempering temperature for a long time, the strength
    of the material will be reduced. Therefore, when this situation is foreseen,
    the high temperature temperature of the material should be limited, or designed
    according to a small allowable stress.

Quality Inspection and Acceptance of Pipeline Materials

In construction and engineering, one of the most pivotal steps toward ensuring safety and efficiency is the quality inspection and acceptance of pipeline materials. Through this, we ensure the system’s integrity, safeguarding lives and properties while guaranteeing smooth operations.
Understanding Pipeline Materials
Pipeline materials are chosen based on many factors, including the nature of the product to be transported, the environmental conditions where the pipeline will be located, and the economic considerations at play. Materials range from steel and plastic to concrete and composite materials, each with unique benefits and considerations.
Quality Inspection: A Rigorous Process
Quality inspection of pipeline materials involves a rigorous process that scrutinizes various aspects. This process is divided into distinct stages, each focused on a particular material component.
Material Receipt Inspection commences as soon as the materials arrive on site. This stage verifies the material’s identity and condition upon receipt, ensuring no visible damages or discrepancies may affect the pipeline’s functionality.
Dimensional Inspection is the second stage, where the dimensions of the material are cross-checked with the specifications. This includes checking the diameter, wall thickness, and length, ensuring they align with the design requirements.
Visual Inspection follows next, with a thorough examination of the material’s surface for any visible defects or deformities. This includes looking for cracks, corrosion, or any signs of wear and tear that could compromise the pipeline’s integrity.
Non-Destructive Testing (NDT) is a crucial step that uses advanced techniques to identify any internal or hidden defects. Methods like ultrasonic testing, radiographic testing, and magnetic particle inspection are commonly employed.
Acceptance: The Final Verdict
Following the quality inspection comes the acceptance process. This is when the materials, having passed all the inspections, are approved for pipeline construction.
Documentation Review is the first step in the acceptance process. Here, we verify that all necessary certifications, test reports, and technical documentation are in order, confirming the material’s compliance with applicable standards and specifications.
Performance Testing is the second step, which validates the material’s ability to withstand operational conditions. This could involve pressure, temperature, and load testing, among others.
Finally, Final Acceptance is granted, signifying that the material meets all requirements and is fit for its intended use. This is a testament to the rigorous quality inspection process and adherence to high safety and performance standards.
In conclusion, the quality inspection and acceptance of pipeline materials is a meticulous process that plays a crucial role in ensuring the safety and reliability of pipeline systems. This is not just a routine protocol but a commitment to excellence and a testament to the importance of delivering quality in our field.

Maintenance and Upkeep of Pipeline Materials

The steps involved in pipeline maintenance can vary depending on the specific pipeline and its environment, but here are some general steps:

  • Planning during the pipeline design phase: Pipelines should be designed and built with future maintenance requirements to ensure ease of maintenance and reduced long-term maintenance costs.
  • Regular inspections and testing: This can involve visual inspections and non-destructive tests like ultrasonic testing, eddy current testing, and leak testing. Drones and robots can be used for inspecting hard-to-reach and remote areas. Underground pipelines may require a preventive maintenance dig before the inspection.
  • Hydrostatic testing: This type of testing is crucial in ensuring pipeline integrity. It involves exerting above-standard pressure on the pipeline using water to ensure it can withstand the pressure exerted by the fluid passing through it. The pipeline segment to be tested is temporarily removed from service by closing the valves at both ends.
  • Tracking pipeline condition: Key parameters such as fluid flow, pressure on pipeline walls, valve pressure, records of inspections, testing records, maintenance records, changes in depth cover, and environmental conditions at different pipeline locations should be recorded and tracked. Condition-monitoring sensors, non-destructive tests, and digital tools such as CMMS can be used to manage this data.
  • Standard operating procedures (SOPs) and checklists can help eliminate common ambiguities and variability in performing common maintenance tasks. They ensure that actions follow best practices and align with health and safety recommendations.
  • Corrosion prevention: Techniques to prevent corrosion, such as using ideal pipe material, corrosion prevention coatings, drying agents, and providing adequate protection from elements, should be actively used to protect the health of pipelines.

There are several challenges associated with pipeline maintenance, including:

  • Pipeline length: Pipelines can run for thousands of miles and across international borders, making them difficult to monitor and maintain.
  • Corrosion: Corrosion is a major health issue for pipelines, which can be located above or below ground and are exposed to various elements.
  • Fluids transported: Pipelines often transport flammable or toxic fluids, which can complicate the repair and maintenance processes, even when the pipeline is shut down .
  • Jurisdiction: When pipelines pass through different jurisdictions, they must adhere to different regulatory standards. Pipelines that go through unstable geopolitical areas can further complicate the process.

As for how often pipelines should be inspected, it depends on various factors such as the type of pipeline, the materials transported, and the regulations in place in a given jurisdiction. In the United States, federal regulations require that pipelines be inspected at least once every five to seven years. Still, some pipelines may be inspected more frequently depending on their age, condition, and the potential hazards they pose.
Preventive maintenance is crucial for avoiding serious problems. For example, a 24-inch pipeline of Energy Transfer LP exploded in Beaver County, PA, in September 2018 due to heavy rain causing a landslide. This disaster might have been avoided with regular checks to ensure the pipelines were in good condition and could withstand the challenges from the terrain.

Choosing the Right Pipeline Material: A Comprehensive Guide

The pipeline construction and operation world is complex and ever-changing, particularly concerning materials selection. As pipelines are integral to our daily lives, spanning sectors from water distribution to oil and gas transportation, making the right choice when it comes to construction materials is paramount.
Traditional Metal Pipelines and Their Limitations
Traditionally, pipelines have been constructed from metal materials. However, metal pipelines face certain challenges. They are susceptible to corrosion, particularly when carrying corrosive fluids, and maintenance can be costly and time-consuming. Furthermore, they are heavy, making transportation and installation arduous tasks.
The Rise of Non-Metallic Pipelines
In recent years, non-metallic pipes, such as plastic (polyethylene, polyvinyl chloride, polypropylene), ceramic, and concrete pipes, have gained popularity in various pipeline networks. Non-metallic pipelines offer several advantages over their metallic counterparts. These include strong anti-pollution ability, lightweight construction, lower costs, resistance to corrosion, and ease of construction and maintenance. Moreover, with advancements in trenchless technology, the construction of urban pipelines has become more practical, economical, environmentally friendly, and secure.
Detecting and Locating Non-Metallic Pipelines
Despite their numerous advantages, non-metallic pipelines pose unique challenges in detection and location. Being non-conductive and non-magnetic, common metal pipeline detectors are ineffective with non-metallic pipelines. However, researchers have developed several methods to accurately and conveniently detect and locate these pipelines.
These methods include electromagnetic induction technologies, where stimulation is placed on a metallic tracer line on the surface of the non-metallic pipeline to produce an induction magnetic field, or a tracer probe is used to locate the position of the non-metallic pipe by the electromagnetic signal intensity generated by a probe placed in the pipe. Ground-penetrating radar and radio frequency identification are examples of electromagnetic wave technologies used for the same purpose. Acoustic technologies, such as pipe excitation, elastic wave, and point vibration measurements, are also employed to locate non-metallic pipelines. Other physics-based technologies, such as infrared thermography, high-density resistivity method, inertial gyroscopes, and electrical capacitance tomography, are used to detect and locate non-metallic pipelines. Lastly, emerging technologies like geographic information systems and in-pipe robot-based inspection are gaining traction.

The Future Trends of Pipeline Materials

Various factors are shaping the future of pipeline materials. As the world moves towards a greener future, there is a growing interest in repurposing existing pipeline networks to transport non-conventional media such as CO2 and hydrogen. This trend catalyzes the industry’s readiness to use modernized techniques and deploy them into operations.
Moreover, the pipeline industry is now adopting more innovations and advanced methodologies, capitalizing on the extensive R&D efforts now invested and the industry’s general shift towards digitalization. This includes using alternative pipe material, welding techniques, modes of inspections, and integrity checks.
To conclude, selecting the right pipeline material involves carefully considering several factors, including the specific application, environmental conditions, costs, and future trends. Material science and technology advancements are continually expanding our options, ensuring that our pipeline networks are efficient, sustainable, and ready for the future.

How to Choose the Correct Supplier of Pipeline Materials

Choosing the right supplier is a key decision that can significantly impact your projects’ efficiency, safety, and financial success.
Understanding Your Requirements
Before embarking on the journey of selecting a supplier, it is crucial to understand your specific needs clearly. This involves identifying the type of pipeline materials you require, the standards they need to meet, and the quantities required. You will be better equipped to evaluate potential suppliers by understanding your needs.
Supplier’s Experience and Reputation
One of the key aspects to consider when selecting a supplier is their experience and reputation in the industry. A well-established supplier with a strong track record of delivering high-quality materials can provide a solid foundation for a successful partnership. Look for suppliers who have been in business for a significant period and have positive reviews from previous clients.
Quality Assurance
The quality of the pipeline materials you procure is a non-negotiable aspect. A supplier committed to quality assurance will likely have robust processes to ensure the materials they provide meet the required standards. This might include certifications such as ISO 9001, API, or others relevant to the industry.
Delivery and Logistics
Another important aspect is the supplier’s ability to deliver on time and manage logistics effectively. You should assess their delivery and logistics capabilities, including their supply chain, transportation arrangements, and contingency plans for unforeseen delays.
Pricing and Financial Stability
While cost should not be the only factor in your decision, it is still essential. However, don’t just focus on the initial cost of materials. Consider the total cost of ownership, including delivery charges, installation costs, and potential maintenance or replacement expenses. Alongside pricing, assessing the supplier’s financial stability is vital to ensure they will remain a reliable partner in the long term.
Customer Service and Support
Finally, a supplier’s customer service and support can significantly influence your overall experience. A responsive supplier who offers technical support and is willing to work closely with you to meet your needs can make the procurement process smoother.
Considering these considerations, you can make an informed decision when choosing the right supplier for your pipeline materials. Remember, this long-term relationship can significantly impact your project’s success. Therefore, taking the time to select the right supplier is well worth the investment.

Source: China Piping System Manufacturer – Yaang Pipe Industry (www.steeljrv.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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