Pressure Vessels

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APPLICATION
Pressure vessels are used in the metallurgy industry to handle fluids (liquids / gases) at pressures substantially different from ambient pressure. The pressure vessels are designed & manufactured in conformance with various national & international standards. The process parameters such as operating pressure, temperature, operating fluid, corrosion allowance, etc. are used to design the pressure vessel.

NOMENCLEATURE
Pressure vessel, surge vessel, tank, surge tank, LP condensate flash drum, HP condensate flash drum, air receiver, etc.

DETAILS
The pressure vessels are mission critical& the design has to achieve the goal of safely handling the operating fluid at the design pressure & temperature. Due consideration has to be given to the operating fluid & welding requirements (which may affect the mechanical properties). The vessel is generally designed in a cylindrical shape with torispherical ends. Composite pressure vessels are gaining popularity on account of their higher strength. Appropriate design &material selection will help drive process performance.

MATERIALS
The pressure vesselsare generally handling process fluids&are fabricated from high tensile strength carbon steel suitable for this application (stainless &alloy steel can also be used, if suitable). The composition of the process gases is used to identify if the provisions of NACE-MR-0103 are applicable. Depending on the process & safety requirements, various internal & external features may be added to the vessel. Due consideration may have to be given to the operating fluid & the internal surface may be lined to protect the structure of the vessel.

QUALITY CONTROL
The pressure vessel is ND tested to determine weld defects, if any. Radiographic examination of the welds may be carried out, if required. The pressure vessel is then hydro-tested at the desired test pressure for a period of 30 minutes. No leakage / pressure drop is acceptable. After completion of testing, the vessel is painted as per the appropriate painting scheme & various internal such as demister, etc. are installed. The vessel is then filled with nitrogen gas to prevent corrosion &sealed.