Pipefitters, sometimes simply called fitters, install and maintain pipes that carry chemicals, acids, and gases. These pipes are used mostly in manufacturing, commercial, and industrial settings. Fitters install and repair pipe systems in power plants, as well as heating and cooling systems in large office buildings. Some pipefitters specialize as gasfitters, sprinklerfitters, or steamfitters.
Master plumbers on construction jobs may be involved with developing blueprints that show the placement of all the pipes and fixtures. Their input helps ensure that a structure’s plumbing meets building codes, stays within budget, and works well with the location of other features, such as electric wires. Many diagrams are now created digitally with the use of Building Information Modeling (BIM), which allows a building’s physical systems to be planned and coordinated across occupations.
Most plumbers wont mess with the septic tank. We deal mostly with components inside the house. Did you have a vent pipe in the yard (often looks like a candy cane made of PVC) before the repair but not after? If all he did was replace the line it shouldn't cause a smell inside the house. All plumbing fixtures inside the house should have properly functioning traps. Those traps would create and maintain a water seal against the sewer gases. You should have at least one vent through the roof to equalize pressures within the drainage system. This prevents positive pressures within the system (caused by fixtures discharging into the lines, ie toilet flush) from pushing gas out through the traps, and negative pressures (the waste in line will pull air behind it like your finger over the end of a straw) from sucking water out of the traps.
The straight sections of plumbing systems are called "pipes" or "tubes". A pipe is typically formed via casting or welding, whereas a tube is made through extrusion. Pipe normally has thicker walls and may be threaded or welded, while tubing is thinner-walled and requires special joining techniques such as brazing, compression fitting, crimping, or for plastics, solvent welding. These joining techniques are discussed in more detail in the piping and plumbing fittings article.
When a person has a blockage in their sewage system they often try to fix it themselves by adding an acid or a base such as Drano in an attempt to dissolve or dislodge the problem. These chemicals can get into the plumbers eyes when the sewage is splashed during the repair. The plumbers skin during the repair does come into contact with the sewage water. The owner of the toilet might not report to the plumber they have already tried Drano a highly caustic base .