Suspended particles in the natural gas transmission and distribution network of the city of Kerman, Iran were investigated. Particle concentration and size distribution were measured in different locations of the natural gas pipeline network. Particle samplings were carried out in two seasons: summer, when there is the lowest consumption, and winter, when there is the highest consumption of natural gas. Additional particle characterization was carried out by scanning electron microscopy coupled with energy dispersion X-ray (SEM/EDX) and X-ray diffraction(XRD) analyses. Particle concentration was found to be significantly higher in winter as compared to summer. The range of particle concentrations in summer was from 0.12 mg/Nm(3) at the end of the pipeline to 4.7 mg/Nm(3) at the network entrance, and from 0.30 mg/Nm(3) to 22.1 mg/Nm(3) in winter. Particle size distribution showed a higher frequency of smaller particles in winter than in summer. Larger particles were more likely to exist at the network entrance as compared to the exit. The average particle size ranged from 181 mu m at the network end to 253 mu m at the entrance in summer, and from 74 mu m to 209 mu m in winter. Particle characterization confirmed the presence of corrosion products in the suspended particles. (C) 2011 Elsevier B.V. All rights reserved.