All venting of CNG shall be done outdoors only under conditions that will result in rapid dispersion of the product being released. Consideration shall be given to such factors as distance to buildings, terrain, wind direction and velocity, and use of a vent pipe or stack so that a flammable mixture will not reach a point of ignition. A vent pipe or stack shall have the open end suitably protected to prevent entrance of rain, snow, and solid material. Provision shall be made in vertical vent pipes and stacks for drainage. Prior to and during venting of the CNG cylinders, they shall be properly grounded so as to eliminate any possible static electrical charges.

Source Note:The provisions of this §13.143 adopted to be effective June 1, 1994, 19 TexReg 3170.