Types of Pipes

Over the years, plumbing and drainage have evolved a lot, moving from the clay pipes that ancient plumbers used to supply water and carry sewage, all the way to the variety of materials we use now. Today, we use different types of pipes for plumbing and drainage systems.

You’ll commonly find seven major types of water supply pipes in houses these days: PEX, PVC, ABS, Flexible Copper, Rigid Copper, Cast Iron, and Galvanized pipes. When it comes to changing the existing plumbing system in your old house, or installing one in your new house, choosing among the types of pipes available in the market can feel confusing

What Types of Pipes Are Used In Homes Based on Application

1. Water supply

Plumbers use pipes to transport drinking water. Water distribution networks use them too, where treatment plants treat and chlorinate the water before distribution to prevent contamination. Types of water supply pipes include PEX, UPVC, CPVC, rigid and flexible copper pipes, and galvanized steel pipes.

• Plumbers widely use PEX, or Polyethylene cross-linked pipes, for water supply in residences and small business establishments.
• Installers use Unplasticized PVC (UPVC) for cold water supply, while Chlorinated PVC (CPVC) pipes withstand higher temperatures and carry hot water.
• Homes commonly use rigid copper pipes for water supply, since they don’t carry any health risks.
• Plumbers use flexible copper pipes in final runs to water refrigerators, water heaters, and sinks.
• Homes have used galvanized steel pipes for decades for water supply, gas supply, fire fighting installations, and other purposes. Galvanized steel pipes are extremely strong.

2. Drainage

Drainage pipes are pipes that carry wastewater from one place to another. Residential and commercial buildings need them to dispose of wastewater. Drainage systems commonly use the following pipes:

• Corrugated Polyethylene drainage pipes, PVC, concrete, clay, and cast-iron pipes.
• Polyethylene drainage pipes are strong, durable, and cost-effective solutions for an efficient drainage system. They are chemically inert plastic and are highly corrosive and abrasion-resistant.
• PVC Drainage Pipe – Polyvinyl chloride pipes are the most common choice, and drainage systems widely use them. These pipes are affordable, durable, and easy to install. Toilet drain lines use them a lot.
• Concrete drainage pipes are cost-effective, strong, and durable. They are eco-friendly and are non-flammable, unlike plastic pipes.
• Clay drainage pipes are strong and eco-friendly. The only drawback is that you have to replace them over time, since they tend to develop cracks when extreme weather conditions and water pressure put them under stress.
• Homes use cast iron pipes in sewer applications. They are tough and durable. Municipalities widely use cast iron pipes because they require low maintenance and can last more than a hundred years.
• Drainage systems have used galvanized pipes since the early 1900s. These pipes are cost-efficient and easily available. However, plastic or PVC pipes later replaced them due to high maintenance, discoloration, and leakage problems.

3. Chemicals

The chemical industry widely uses stainless steel pipes. Stainless steel is a versatile material made of a steel alloy and a small percentage of chromium. Manufacturers add chromium to make the material resistant to corrosion. Apart from SS pipes, the chemical industry can also use Polyvinyl Chloride (PVC) or Unplasticized Polyvinyl Chloride (UPVC) pipes, based on the chemical resistance chart the manufacturer provides.

4. Pneumatics

Compressed air systems use plastic and metal pipes. Pipes and fittings are the components that connect everything in a compressed air system.

• Manufacturers make ideal plastic pipes for compressed air from Acrylonitrile Butadiene Styrene (ABS), Polyethylene (PE) piping, and High-density polyethylene (HDPE) piping.
• Air compression systems use metal pipes like black steel pipe, galvanized steel pipe, copper pipe, aluminum pipe, and stainless steel pipe.

5. Pressure vs. Non-Pressure Application

Pressure Applications
Pressure piping uses ABS, PE, PVC, cast iron, steel, cement concrete, and asbestos cement pipes. It covers a wide range of applications, including water supply, sewerage, gas reticulation, compressed air, mine and slurry pipelines, coal seam gas collection, irrigation, and drainage.

Non-pressure applications
Non-pressure applications like storm water drainage pipelines, ocean outfalls, road culverts, gravity sewer mains, and ventilation ducts use Polyvinyl Chloride (PVC), Polypropylene (PP), and PE pipes.

6. Material

Metal pipes
Metal pipes include Cast-iron pipes, Galvanized Iron pipes, Copper, Aluminum, and Stainless Steel (SS) pipes.

Non-metal pipes
Non-metal pipes include cement and ceramic pipes. Manufacturers make Asbestos Cement pipes from asbestos paste and cement, compressed by steel rollers to form a laminated material. This material has great strength and density.

Plastic Water Pipes:
Some of the plastic pipes available in the market are
PVC – Polyvinyl Chloride Pipes, HDPE- High-density polyethylene (HDPE) piping. LLDPE – Linear low-density polyethylene (LLDPE), MDPE – Medium-density polyethylene, CPVC- Chlorinated Polyvinyl Chloride, PP- Polypropylene,
PPR – Polypropylene Random pipes, PEX – Polyethylene cross-linked pipe, PERT – Polyethylene of Raised Temperature, PVDF – Polyvinylidene Fluoride, ABS – Acrylonitrile Butadiene Styrene, PU – Polyurethane Pipe, FPVC – Fusible PVC pipes and Rubber pipes.

7. Structure

Solid Wall
Solid wall pipes are those extruded pipes consisting of one layer of a homogeneous matrix of thermoplastic material ready for use in a pipeline.

Structured wall
Manufacturers design structured wall pipes to develop maximum pipe stiffness and meet other physical, mechanical, and performance requirements.

Multi-layer pipes have four layers. The first layer uses PEX and contacts the liquid being transported. The second layer is an aluminum layer, and the third layer is the external protective PE (Polyethylene) layer. Between each layer, the pipe has two intermediate adhesive layers that keep them joined.

8. Stiffness

Flexible Pipes:
Flexible pipes are the type of water supply pipes that connect the plumbing fixtures and appliances. Instead of connecting directly to the water supply pipe, flexible pipes connect to a fixture shutoff valve attached to the water supply pipe. Types include braided nylon flex tubes, stainless steel braided flex tubes, PVC flex tubes, and polymer-coated flex tubes.

Rigid Pipes
Manufacturers make rigid pipes from plain concrete, reinforced concrete, vitrified clay, cast iron, and asbestos cement. They have the strength to support more load.

Types of pipe jointing systems

Threaded joint

It is the mechanical joint between threaded pipes or between a threaded pipe and threaded fitting.

It is a joining process that joins together different types of metals by melting solder.

Metal Heat welding

It is a fabrication process that joins metals or thermoplastics by using high heat to melt the parts together.

Plastic heat welding

It is the process of creating a molecular bond between two thermoplastics.

Solvent cement

It comes in either liquid or gel form. Installers use it to join PVC pipes and other types of plastics. Solvent cement is very convenient to use.

Rubber ring

In this technique, compressing a rubber ring housed in the socket of a pipe or fitting provides a fluid seal when the spigot passes into the socket.

Crimping is a device used to join two pieces of metal. This process deforms either or both metals so they hold each other.

It is an assembly method used to attach flexible parts, especially plastics, to form the final product. Installers push the interlocking components of the parts together.

Installers use this technique to connect two pipes, or a pipe and a fixture or valve.