One common requirement that unites the most diverse engineering projects is the need to make many decisions and to plan out many details. One of the most important aspects in any job is your choice of materials.
For certain industries, forged metal flanges are essential. They are used to temporarily join elements that make up a piping system, with the addition of bolts and a gasket between the two flanges. They can be made of different materials depending on the environmental conditions and the use they will be subjected to, issues such as temperature, pressure and loads.
What are forged flanges?
Forged flanges, attached with bolts and a gasket at the juntion point, are used to join up pipeline parts in order to ensure that they remain firmly in place and stay watertight, but also to ensure they are easy to dismantle.
Metal flanges have a multitude of applications thanks to their mechanical properties and load-bearing capacity, which is why they are most often found outdoors, as can be the case in industries such as petrochemicals, oil & gas, etc.
In thinking about the function that these pieces are going to take on and the working conditions they may be used under, we consider that:
For moderate temperatures, the most commonly used flanges are made of carbon steel.
Harsher climates require materials that can withstand variations in pressure and temperature, for which alloy and stainless steels, etc. are recommended.
If they are going to be in contact with corrosive liquids or gases, the material must be anti-corrosive and resistant to high temperatures. Therefore, nickel alloys, chromium and molybdenum are usually used.
Use of flanges in the petrochemical industry
Forged flanges play an important role in the petrochemical industry, as this is where a multitude of oil and gas pipelines made up of pipes and other components are found:
Pipelines are systems that are responsible for transporting oil and derivatives such as biobutanol by means of a system of pumping stations that drive the fluid at an average speed of between 1 and 6 meters per second. Given the complexity and dimensions of their structure, studies on the environmental impact must be carried out before construction. They are centered on steel pipes whose diameter varies from ½ inch (12.7 mm) to 144 inches (approximately 360 cm).
Gas pipelines have the same function, transporting materials, but in this case the materials are combustible gases, mainly natural gas. They do this at high pressures. The lines are mostly built underground at a depth of one or two meters depending on the terrain; rarely above ground. It is standard practice that shutoff valves be placed at various points in the pipeline to cut off the flow of gas if necessary.
In both cases, pipelines are used to transport materials that require specific treatment both in their extraction and in their transportation or processing. Oil and its derivatives are very corrosive and contaminating, and natural gas can flow at low temperatures (-161º). The materials that both types of conduits are made from need to be just right for their planned application to avoid negatively affecting the surrounding flora and fauna. This is also why sections of pipe are joined with forged flanges, whose corrosion resistance can be increased thanks to techniques such as cladding / weld overlay, also applied by ULMA.
