Frequently Used Pipe Material

There are two types of pipe material which is frequently used either in oil and gas industry, power plant and other industries:

1. Carbon Steel

Carbon Steel is one of pipe material and it is the most widespread of use in the oil and gas Industry, power plant and other industries. Almost all of these pipe materials have specifications issued by ASTM (American Society for Testing and Materials) and ASME (American Society of Mechanical Engineering.

There are three types of Carbon Steel are the most widely used, namely:

-          ASTM A106, This type has three grades, namely Grade A, B, and C. This grade refers to the amount of Tensile Strength materials. The amount of Tensile Strength of ASTM A106 are:

·         Grade A: 48 ksi

·         Grade B: 60 ksi

·         Grade C: 70 ksi

Among the third grade, pipe material which is usually used is ASTM A106 Grade B.

-          ASTM A 53: This material is also often used by elements of pipe that are coated by zinc (galvanized), or often used as an alternative for the A106 type. Grade A53 has three grades, namely Grade A, B, and C. In addition, A53 also has three types, namely:

·         Type E: Electric Resistance Weld

·         Type F: Furnace Butt Weld

·         Type S: Seamless

A53 Grade A and B have same Tensile Strength with ASTM A106 Grade A and B.

-          ASTM A 333: This material is often used on the fluid having low temperature, ranging from -50^oF.

2. Stainless Steel

Pipes are often categorized in Stainless Steel pipe is actually having the full name of austenitic stainless steel. But this pipe material is more often known by the name of Stainless Steel.

Stainless Steel has Grade 18, but type 304L is often used. In essence, Type 304 is the type that has low carbon content with the aim of strengthening the ability to withstand corrosion. With the addition of L letters behind his name, the 304L, it shows that this type has lower carbon content, much lower than just 304.

Thus, in application, there are two types of stainless steel that is commonly known and used in oil and gas industry and other industries as follow:

-          ASTM A312: This standard is used for pipe sizes under 8 inches.

-          ASTM A358: This standard is used for pipe sizes above 8 inches.

There are many other types of pipe material is quite often used beside two pipe materials above (carbon steel and stainless steel) such as:

-          Chrome-Moly Pipe: namely Chromium-Molybdenum Alloy Pipe, which consist of 10 grades, and refer to ASTM A335.

-          Nickel and Nickel Alloy Pipe: example that is widely used is Inconel, Incoloy and Monel.

-          Piping Cast iron, Cooper Piping

-          Plastic Pipe, concrete pipe.

Pipe Material

Piping systems we often encounter in our lives, whether in the office, buildings, power plants, offshore plants, and so forth. Pipes can also easily be found on the construction of a fertilizer factory, or in refineries processing crude oil, both for the processing of oil on land and at sea.

Most often we find and see is the pipelines system to deliver water to the houses made almost entirely of metal and sewerage pipes from plastics material or also commonly called Polyvinyl chloride (PVC).  Pipe has certain size, ranging from the smallest with diameter of ½ inch to an enormous size so that people can enter into it, that is a pipe with a diameter of 72 inches or approximately 1.8 meters.

In general, pipe materials that are widely used for piping and its components are divided into two main categories namely:

-          Metallic pipe material

-          Non-metallic pipe material

Especially for metallic pipe material, this pipe material can be subdivided into two main groups namely Ferrous and Non-Ferrous pipe material, including nickel, alloys, copper and aluminum. Finally, from the manifold types of ferrous materials, the pipe material can again be divided into two general categories:

-          Wrought iron, cast iron

-          Steel

Almost all pipe materials are widely used in oil and gas industry is made of steel, with the following main characteristics:

-          Chemical: major elements (iron for Ferrous Metal), alloying elements (nickel, chromium, etc.), impurities, and others.

-          Physical properties; density, modulus of elasticity, coefficient of thermal expansion, and others.

-          Micro Structure: atomic structure, phase metallurgy, type and grain size.

-          Mechanical Properties: strength (yield strength, ultimate strength, elongation) and toughness.

Evaluation Parameter of Pipe Material Selection

Operation of piping system will receive variety of loads from the operating condition and environment. The right and suitable selection of pipe material for operating condition and environment will be initial guarantee that failure will not occur in the operation. The following below are some of key information that can be used to evaluate the selection of pipe material in order to achieve safe condition during operation:

1.      Maximum operating pressure which working on the piping system.

2.      Calculation to determine diameter and thickness of pipe.

3.      Material strength needed to hold the weight of fluid contained therein, the weight of component piping, insulation and the weight of pipe itself.

4.      Maximum and minimum operating temperature.

5.      Production method on special order condition.

6.      Composition of fluid either gas phase or liquid phase which flow inside pipe.

7.      Erosion problem due to the flow of sand which is carried in the fluid process.

8.      Corrosive particle that potentially cause corrosion in the pipe such as H₂S, CO₂, O₂, etc.

9.      Design lifetime of piping system during operation.

In piping system can be found technical terms such as SMYS (Specific Minimum Yield Strength) and SMTS (Specific Minimum Ultimate Tensile Strength) which show yield strength and tensile strength for pipe material respectively. Naming grade in code API 5L, on some types of pipe material can be sorted by SMYS value to make easier in the analysis of pipe material selection. But on other grade, naming system does not depend on SMYS value. The following table below show pipe material in Code API 5L where the naming of its grade in accordance with SMYS value.

Table 1: Standard API  for Pipe Material Grade 5LX

Pipe Material Selection

Metallic materials began to be used for piping system regularly in 1950s as implementation of Code API 5L about steel material selection for piping system. At the end 1980s there were various kinds of steel material for pipe based on the grade which was set by API such as grade A25, A, B, X42, X46, X52, X56, X60, X64, X70 and X80. In each grade there are differences in mechanical properties depending on chemical content and its containing material. Specifications steel material in the manufacturing process generally refers to chemical composition, material strength, and manufacturing tolerance.

Some criteria should be determined to get right material and suitable for piping system design. The following below are the criteria that can be used in the analysis of pipe material selection:

-          Mechanical properties, include:

Material strength to resist static load

Material toughness to resist dynamic load

Material ductility due to installation piping system process

-          Weld ability

Ability of material pipe to be easily welded or not.

-          Corrosion resistance

Material pipe ability to resist corrosion.

-          Cost, relating to the price of material pipe to be used.

-          Availability

Relating to availability of material pipe on the market in large numbers, this condition should be analyzed to avoid special order that allow high price for the production.