Bulkhead means an airtight structure separating the working chamber from free air or from another chamber under a lower pressure than the working pressure;
Pipe or “Piping” means a hollow cylinder or tubular conduit that is constructed of non-earthen materials.
Diameter means the diameter of the stem of a tree measured outside the bark at a specified point of measurement.
Sump means any pit or reservoir that meets the definition of tank and those troughs/trenches connected to it that serve to collect hazardous waste for transport to hazardous waste storage, treatment, or disposal facilities; except that as used in the landfill, surface impoundment, and waste pile rules, “sump” means any lined pit or reservoir that serves to collect liquids drained from a leachate collection and removal system or leak detection system for subsequent removal from the system.
Wax means a material or synthetic thermoplastic substance generally of high molecular weight hydrocarbons or high molecular weight esters of fatty acids or alcohols, except glycerol and high polymers (plastics). “Wax” includes, but is not limited to, substances derived from the secretions of plants and animals such as carnuba wax and beeswax, substances of a mineral origin such as ozocerite and paraffin, and synthetic polymers such as polyethylene.