Archive for: ‘January 2012’
The wall thickness associated with a particular schedule depends on the pipe size as can be seen from the charts below for some of the more common sized carbon steel pipes encountered.
Abbreviations used: NB - nominal bore, STD ... Read More...
For all pipe sizes the outside diameter remains relatively constant. Therefore any variation schedule i.e. wall thickness, affects only the inside diameter. As the schedule number increases, the wall thickness increases, and the ... Read More...
In the oil and gas and related down stream industries the the most common standards are
- API 5L
- ASME/ANSI B 36.10 Welded and Seamless Wrought Steel Pipe
- ASME/ANSI B36.19 Stainless Steel Pipe
Related posts:What is a pi... Read More...
Pipes are designed to carry fluid, therefore their internal diameter is their critical dimension. This critical dimension is referred to as the nominal bore, appreviated as NB. Obviously, for pipes containing pressurised fluids t... Read More...
Applies for plain carbon and low-alloy steels and cast steel and to a limited extent for high-alloy and/or work hardened steel.
Hardness Conversion Table
Tensile
Strength
(N/mm2)>
Brinell Hardness
(BHN)
Vicke... Read More...
Material
Density
(g/cm3)
Liquids
Water at 4 °C
1.0000
Water at 20 °C
0.998
Gasoline
0.70
Mercury
13.6
Milk
1.03
Solids
Magnesium
1.7
Aluminum
2.7
Brass
8.55
... Read More...
The various Titanium Grades as defined by ASTM and ASME are numbered from 1 and upwards where all numbers except 6 and 8 are represented.
Most of the grades are of alloyed type with various additions of for example aluminium, va... Read More...
The proportional limit is the highest stress at which stress is linearly proportional to strain. This is the same as the elastic limit for most materials. Some materials may show a slight deviation from proportionality while stil... Read More...
The elastic limit is the highest stress at which all deformation strains are fully recoverable. For most materials and applications this can be considered the practical limit to the maximum stress a component can withstand and st... Read More...
Strength has several definitions depending on the material type and application. Before choosing a material based on its published or measured strength it is important to understand the manner in which strength is defined and how... Read More...
Creep is slow, temperature aided, time dependent deformation. Creep is typically a factor in materials above one third of their absolute melting temperature or two thirds of their glass transition temperature. Creep resistance is... Read More...
Thermal conductivity
The thermal conductivity is the rate of heat transfer through a material in steady state. It is not easily measured, especially for materials with low conductivity but reliable data is readily available for ... Read More...
Copper have good resistance to corrosion in urban, marine, and industrial atmospheres. The major factors that control the initial rate of attack on copper are moisture, temperature, and the level of pollution. Soon after exposure... Read More...
Galvanic corrosion occurs when two dissimilar metals having different electrical potentials are electrically connected.
Aluminum and Aluminum alloys become the anode in galvanic cells with most metals. The rate of galvanic corro... Read More...
The methods for avoidance of galvanic corrosion are in general suggested by the above descriptions of the conditions necessary for its occurrence.
Don’t Mix Metals. If only one material is used in a construction the problem is... Read More...
Stainless steel naturally form passive surface films this is what makes them “stainless”. This film also reduces the amount of current available for corrosion, so slows the corrosion rate down compared to some other galvanic ... Read More...
The relative area of the anode and cathode has a pronounced effect upon the amount of corrosion that occurs due to Galvanic Corrosion. A small anode (the less noble metal, such as aluminium) joined to a large cathode (the more n... Read More...
For galvanic corrosion to occur there are three conditions which must be met:
Condition 1. Metals must be far apart on the galvanic series
The galvanic or electrochemical series ranks metals according to their potential, gen... Read More...