The most common materials used to make gas pipes are steel, black iron, polyvinyl chloride (PVC), high-density polyethylene (HDPE) and copper. Some utilities prohibit some of these materials, so be sure to check with your local utility company to determine what is allowed in your area before installing any. PVC pipes will work well for natural gas lines and water supply. They are usually available in 10 foot and 20 foot sizes, and come in different diameters.
Size ranges from ½ inch to 6 inch to choose one depending on purpose. If you want to fix PVC pipes, you will need solvent cement, primer or a pressure fitting. However, you will have to remember not to install PVC pipes where sunlight flows directly. When exposed to hot water or direct sunlight, PVC can be damaged.
If you use it for natural gas, make sure it flows through a cold or dark area. Remember that these pipes must be installed by professionals who know the work. They usually come in lengths from 2 inches to 10 feet and have a diameter of ¼ to 2 inches. Many people use a black pipe to transfer natural gas to the house from the outside.
People have been using copper tubes for years to transfer hot and cold water. These tubes range in length and are usually between 2 and 10 inches in size. Each dimension from ½ to 1 inch ensures water and gas flow easily. Steel pipes can be used above ground as long as corrosion due to the environment and transport gas is not a problem.
Steel and copper pipes are the most commonly used materials inside buildings. Copper pipes used in gas systems must be L or K type and approved for gas. Yellow brass tubes can be approved for indoor installations. Aluminum tubes should not be used on the ground.
Aluminum is not approved in all jurisdictions. Ductile iron pipes may be approved in some jurisdictions for underground work. Water and gas require piping to supply residential homes and businesses. Gas supplies power to stoves, water heaters, ovens and other devices.
The two most common types of steel pipes used to transport water and gas are black pipes and galvanized pipes. Confusion is common among homeowners, and even some professionals, as to where to use these steel pipes and under what circumstances. Data other than given will be obtained on the size of the gas pipe just above if you are designing a 2 psig gas line. In my experience, both types of pipes work well, and the IRC and the National Combustible Gas Code allow both, along with stainless steel corrugated tubing (CSST) and copper tubing (with some limitations), to be used for natural gas distribution pipelines.
BarbaraA Google Scholar search on rodent damage to gas pipelines and similar phrases came up articles on rodent-proof construction, but no specific article (at least not on the first pages I scanned) reporting an incident of rodents chewing metal gas pipes. You would not use propane gas connectors or other parts on a natural gas barbecue BEFORE reading the specifications of your specific product. There is a large list of types of piping materials approved for use in gas piping systems; the distinctions I have seen concern the application: location above or below ground rather than fuel difference between LP and NG; historically there have been opinions on gas piping and corrosion differences between sources (hence the history of dirt branches in NG piping systems. But natural gas is much cleaner than it was 40 years ago, and almost all fuel gas goes through a sulfur recovery unit before entering the distribution system today.
The piping upstream of the gas meter and the meter itself are usually the responsibility of the gas company. Rather, one needs to make a simple arithmetic, observing the lengths of the pipes, the diameters, the type of fuel AND the input BTUH (or cubic feet of gas per hour) that the appliances in the gas piping system required. I can't answer your question about the gas manifold, as it is a local plumbing decision based on space, convenience and other factors suggested here. Take a look at the materials and also the requirements for converting a propane gas grill to natural gas; my second illustration will be published in a minute.