Process for pretreating a natural gas under pressure containing hydrocarbons, acid compounds such as hydrogen sulfide and carbon dioxide, and water. The sealing film provides a seal preventing mixing of ink from each of the plurality of ink paths at an underside of the ink distribution support. The spray device further includes an inclined surface, a tightening contact surface provided on an outer surface of a circular head part of the upper body, a working groove to provide an internal thread on the lower body, and a hemispherical mesh which has a convex shape and is provided in a chamber defined at a center position between the upper body and the lower body.