MATERIAL SPECIFICATION FOR STEEL PIPES

DO NOT CONFUSE SPECIFICATION WITH STANDARD  DIMENSIONS.

 IN CASE OF PIPES ARE THE MOST COMMON SPECIFICATIONS:

•  Carbon steel
  • A-53
  • A-106
  • A-120
   
•  stainless steel
  
  
  
  

  	C% (máx)	Mn%	Si% (Mn)	Break (Kg/mm2)	Flow (kg/mm2)
  Grade A Grade A (Low Carbon) Grade B (Medium carbon) Grade C (Medium carbon)	0,25 0,30 0,35	0,27- 0,93 0,29 – 1,06 0,29 – 1,06	0.10 0,10 0,10	34 41 48	20 24 27

  Example table for ASTM A-106
   
  

COMPARE COSTS OF MATERIALS

The cost comparison should be made by comparing the cost / or mechanical strength, comparison should be made between the adjusted prices to be multiplied by the price per kg weight divided by the specific allowable stress of each material.

 
When comparing costs of materials should also be taken into
consideration the following points:

1.  Resistance to corrosion;
2.  More or less difficulty in welding;
3.  More or less ease of shaping and working; 
4. Whether or not need stress relief;

  

ON COST OF MATERIALS

Materials                                                         Relative Cost
                                                

Carbon Steel Structural                                       1.00
Cast iron                                                           0.95
Qualified carbon steel                                         1.15
aluminum                                                          2.5
Alloy Steel 1.25 Cr - 0.5 Mo                                  3.1
Aluminum brass                                                  7.6
Stainless steel type 304                                     11.5
Monel Metal                                                      31.8
Stainless steel type 316                                     15.0
titanium                                                           41.0

  

CARBON STEEL PIPES

 LOW COST

 EXCELLENT QUALITY MECHANICAL     

 WELDING AND EASY TO CONFORM

Represents 90% of Pipe Industries

 USED ​​FOR:
Fresh water, steam, condensate, compressed air, oil,
gases and many other slightly corrosive fluids.

 LIMITS OF TEMPERATURE FOR WORK

•  450 º C for severe service
•  480 º C for service  not severe
•  520 º C maximum peak
  
• 370 ° C creep flow begins
• 530 ° C severe oxidation (scaling)
• -45 ° C becomes brittle

THERE ARE SPECIAL CARBON STEEL FOR LOW TEMPERATURES
MORE WITH LESS CARBON AND MANGANESE;

FOR TEMPERATURES BELOW 0 º C and 400 º UP IS RECOMMENDED THE USE OF CARBON STEEL calmed (1% Si).

The CARBON STEEL EXPOSED TO SUFFER THE ATMOSPHERE UNIFORM CORROSION (rust) AND DIRECT CONTACT WITH THE GROUND CONCERNED PENETRATING  PITTING.

A GENERAL METHOD HAS LOW CARBON STEEL CORROSION RESISTANCE (use with coated or play with higher thickness)

 WASTE OF CORROSION OF CARBON STEEL ARE NOT TOXIC BUT MAY AFFECT THE COLOR AND TASTE OF FLUID DRIVEN.

 The CARBON STEEL is attacked violently from MINERAL ACIDS, diluted or ESPECIALLY WHEN HOT AND REASONABLY SUPPORTS THE SERVICE with alkali.

THE CARBON STEEL TUBES ARE SOLD WITHOUT TREATMENT (BLACK TUBE) OR PROTECTED WITH ZINC COATING DEPOSITED HOT (GALVANIZED PIPE).

 LEAGUE STEEL PIPES AND STAINLESS STEEL 

 Pipes alloy steels and stainless steels are much more expensive than carbon steels, in addition to welding, forming and assembly are also more difficult and more expensive.

 GENERAL EMPLOYMENT CASES
high temperatures
low temperatures
high corrosion
Need for non-contamination
security

 Definitions:

 The alloy steel are all other steels containing elements other than those which comprise the carbon steel.

 Alloy steel, piping, stands out two important classes:

•  Improves creep resistance at high temperatures;
  
•  Improved oxidation resistance at low temperatures;

Stainless steels are those containing at least 12% chromium which give them the property not to rust even on prolonged exposure in a normal atmosphere.

 

 Stainless steels can be;

•  AUSTENITIC (non-metallic)
  
  • Intergranular corrosion by the precipitation of Cr carbonetode - sensitization (T> 450)
  •  Corrosion caused by alveolar ion chloride (chlorides, hypochlorite etc.). 
   
•  FERRITIC (magnetic)

 

 

 

 

 

 

COMMENTS ON THE SELECTION OF MATERIALS

To solve the problem of choice of materials, experience is essential and irreplaceable ie material to be good may have been used by someone previously. Following the experience is the safest, although not always lead to more economical solution.

 
In short, you can indicate the following procedure for selection of materials:

 

1. Knowledge of materials available in practice and their physical limitations and manufacturing.
   
2. Select the most appropriate group for the case with a view to working conditions, corrosion, etc. voltage level.
    
3. Compare the various materials selected economically, taking into account all cost factors.

 

FACTORS INFLUENCE THE SELECTION OF MATERIALS

The proper selection is a difficult problem because in most cases, the determinants may be conflicting. If corrosion is typical versus cost.  

The main factors that influence are:

1. Fluid Driven -
   Nature and concentration of impurities or fluid
   contaminants, pH, velocity, Toxicity, resistance to corrosion; chance
   contamination;
   
2. Terms of Service -
   Temperature and pressure. (given the extreme conditions, even if transient conditions or possible);
   
3. Stress level of the material -
   The material must have mechanical strength compatible with the magnitude of these efforts. (Fluid pressure, weight, wind loads, thermal expansion reactions, overloads, assembly efforts, etc);
   
4. Nature of Mechanical stress -
   Traction, compression, bending, static or dynamic efforts; s shock, vibration, etc. Efforts cyclical;
   
5. Availability of materials -
   With the exception of carbon steel materials has limited availability;
   
6. System calls -
     Appropriate for the type of material and the type of mounting;
   
7. Cost of materials -
   Often a decisive factor. You should consider the direct cost and indirect costs also represented by the lifetime, and the resulting replacement costs and system downtime;
   
8. Security -
   The greater or lesser degree of security required will depend on the strength and lifetime;
   
9. Easy to fabrication and assembly -
   Among the limitations include the weldability, machinability, ease of shaping, etc.;
   
10.  Previous Experience -
    It is risky to decide on a material that does not know any previous experience in similar service;
    
11. Expected life -
    The lifetime depends on the nature and
    importance of the pipe and the time of return on investment. time
    life for the purpose of project is approximately 15 years;

MATERIALS FOR PIPE

It is a very large variety of materials currently used for
manufacture of pipes. Only ASTM specifies more than 500 types.

 METALLIC

 FERROUS

 

• Carbon steels 
• Alloy steels  
• Stainless steels 
• Cast iron 
• Wrought iron
• Irons attached 
• Ductile iron

 NON-FERROUS

• Copper 
• Brasses 
• Copper-nickel 
• Nickel and alloys
• Monel Metal
• Lead
• Titanium, zirconium

NON-METALLIC

 

PLASTICS

• Polyvinyl chloride (PVC) 
• Polyethylene Acrylics 
• Cellulose acetate 
• Epoxy Polyesters 
• Phenolics, etc..

 ASBESTOS CEMENT

 

 CONCRETE

 

 STONEWARE

 

 ELASTOMERS (rubbers)

 

 GLASS

 

 CERAMICS, PORCELAIN, etc..

 

 The selection and specification of the material most suitable for a particular application can be a difficult problem of the solution depends several factors.

PIPE MANUFACTURING PROCESSES

1. SEAMLESS TUBES
   
   • Rolling Large Diameter
   • Extrusion Small Diameter
   • Foundry
2.  TUBES WITH SEAM
   
   • Manufacture by welding

Pipes Industrial: General, rating.

INDUSTRIAL PIPES

 
Definition: 

 A set of pipes and fittings

 
Applications: 

Distribution of steam for power and / or heat; Distribution of drinking water or industrial processes;

Distribution of fuel oils or lubricants;

Distribution of compressed air;
Gas distribution and / or industrial liquids.

 
Cost:  

In process industries, chemical plants, oil refineries, petrochemical industries, much offood and pharmaceutical industries, the cost of piping may represent 70% of the cost of equipment or 25% of total installation cost.

CLASSIFICATION OF PIPES

 

1. Pipelines within industrial plants
   Process piping
   
   Pipes Utilities
   
   Piping instrumentation
   
   Drainage pipes
2. Pipes outside industrial plant
   
   Pipes Transport
   
   Pipes Distribution

Structure of Learning Modules

Program and Lesson Plan

      

1. Tubing & Pipes  - Definitions
   Pipes: Materials, Manufacturing Processes and Standards Exposure Theory dimensional
2. Means of Connecting Tubes, Pipe Fittings and Joints
   expansion
3. Valves
4.  Steam Traps, Separators and Filters
   Recommendations for Material Services
5. Heating, Insulation, Painting and Protection
6.   Disposition of Buildings in an Industrial Installation
   Piping Layout and Detailing
7.  Special Systems Pipeline
   Pipe Stands
   Assembly and Test Pipes
8. Drawings Piping
9. Pipes Design
10. Assessment Exercise

Online Training Course

The material in this course, organized in 10 modules called Class 1 to Class 10, contains all the procedures that are used for each class and summaries correspond to the respective chapters of the Textbook.
In the organization of each course module, besides the Book Text, tables and graphs were used in the book help as well, figures and data from several catalogs of manufacturers of pipes, fittings, expansion joints, valves, steam traps, etc. ...
To ensure effective use in the course, students should start using transparencies with summaries of the book text. Text only through the book is that it will achieve full understanding of the abstracts presented in this material.