Mechanism of silicon carbide coating on the internal surface of the graphite tube of dimension Φ3mm IDXΦ10 mm OD x Φ235 mm and surface area ~24.5 cm² has been investigated. Atmospheric pressure chemical vapor deposition (APCVD) method in mass controlled doma in has been applied. Methyltrichlo-rosilane (MTS) as precursor was used in the present investigation. The coating was characterized by X-ray micro tomography (μCT). The coating thickness and composition were analyzed by scanning electron microscopy energy-dispersive spectroscopy (SEM–EDS). The coating phase analyzed by X-ray diffraction (XRD). It has been concluded that silicon carbide coating is a predominantly boundary layer phenomena and the engineering of the same could open up the prospects to accomplish SiC coating on complex pipe line structures on macro scale.