There are different types of pipes for different types of applications. Every situation has a set of the specific needs to be addressed for that project and the type of pipe to be used. I prefer to use a PVC pipe underground for a water main for the following reasons in California.
1- PVC pipe resists corrosion from the soil it is placed in and will not rust or deteriorate.
2-PVC pipe is much less expensive than copper pipe to install and i can save homeowners money on material costs.
3-PVC resists scale and hard water build up a little better than metal pipe.
4- PVC pipe is easier to install and can bend without the use of fittings for subtle turns or angles.
5-The water will not wear or weaken the PVC pipe. Copper although slowly will weaken with the chlorine and other chemicals found in our water.
6-PVC is not effected by electrolysis unlike copper.
Less conductive I would say.
Iron rusts easily when combined with water, and drain pipes have water flowing through them. If iron was used, the pipes would rust within a few days.
galvanized water lines, cast iron drain lines, sometimes lead pipes, terracotta or clay pipes, and in rare cases wooden pipes.
It is safe, but it will rot out. It is used to prevent electrolysis, but that is pretty much it nowadays. Pex is more commonly used for water pipes.
One reason is because it resists corrosion and another reason is that it can easily be made into pipes for hot and cold water, oil, etc. However, compared to modern plastic materials, copper is much more expensive to use: its ore must first be mined, then the ore has to be smelted and refined into metal pipes, wires, etc. So nowadays, for drainpipes, plastic pipes are used instead of copper.
Cememt lined CI is used for potable water systems
Before copper and plastic pipes became available people used to use lead, iron or steel to make water pipes. Nowadays main water supply pipes for fresh water coming into buildings are made of plastic and pipes within buildings - delivering water to sinks, baths, showers and toilets - are made either of copper or plastic. Within buildings, pipes which take away waste water - which are also called drainage pipes - are usually made of plastic. Outside buildings, modern drainage pipes are mostly made of plastic but older drain pipes may be made of glazed earthenware (which is baked clay) or iron.
I believe they used horse hair and or lead wool.
Copper, iron, and lead are commonly used in construction for pipes and electrical wiring because they are good conductors of electricity and heat, resistant to corrosion, and readily available. Zinc and magnesium are not as commonly used due to their lower conductivity, higher reactivity, and susceptibility to corrosion over time in certain conditions.
The drained material contains acidic materials which are highly reactive towards Iron and Iron is easily corroded by water and oxygen so iron is not suitable for drainage pipes.
Iron is used !
Copper pipes are now most commonly used in plumbing. Lead pipes were used long ago, and the word plumbing is derived from the Latin word for lead (plumbum). Iron pipes were used until relatively inexpensive copper pipes became readily available during the twentieth century.