Unit 305 session 5 PT2 (Plastics)

​Properties of materials Part2

Plastics

Word Cloud

Where do you think we use plastics in plumbing systems?

​Just as plumbers should know their metals, they should also know their plastics if mistakes during installation are to be avoided.

There are many different plastics that plumbers use in their day-to-day work for installing hot and cold water supplies, central heating, guttering and rainwater pipes, and above-and below-ground drainage systems.

​Did you know Plastic was invented over 100 years ago, its original purpose was to replace ivory billiard balls.

​There are two basic types of plastics:

Thermoplastics
and
Thermosetting plastics

​Thermoplastics:

A thermoplastic is a type of plastic made from polymer resins that becomes liquid-form when heated and hard when cooled.

When frozen, however, a thermoplastic becomes brittle and subject to fracture.

These characteristics are reversible and it can be reheated, reshaped and frozen repeatedly.

This quality also makes thermoplastics recyclable.

​Thermosetting:

thermosetting plastics, are rigid plastics, resistant to higher temperatures than thermoplastics.

Once it has set, a thermosetting plastic cannot be remoulded.

Its shape is permanent and it does not melt when heated.

They are not normally recyclable.

Poll

Which do you think is best?

• Thermoplastic

• Thermosetting plastic

​In truth we need both:
thermoplastics for flexibility and recyclability, and thermosetting plastics for durability and heat resistance.

Labelling

Which plastic do you think the bottle trap is?

Drag labels to their correct position on the image

Thermosetting plastic

Thermoplastic

Labelling

Which plastic do you think the solvent weld waste tee is?

Drag labels to their correct position on the image

Thermoplastic

Thermosetting plastic

Labelling

Which plastic do you think the push fit elbow is?

Drag labels to their correct position on the image

Thermoplastic

Thermosetting plastic

Labelling

Which plastic do you think the toilet seat is?

Drag labels to their correct position on the image

Thermosetting plastic

Thermoplastic

Labelling

Which plastic do you think the soil tee is?

Drag labels to their correct position on the image

Thermosetting plastic

Thermoplastic

Labelling

Which plastic do you think the push fit waste elbow is?

Drag labels to their correct position on the image

Thermoplastic

Thermosetting plastic

Open Ended

Use the internet to find out where we use 'PEX Tubing' in plumbing

Open Ended

Use the internet to find out where we use 'PVC Pipes' in plumbing

​Thermoplastics in Plumbing:

PVC Pipes: Commonly used for drainage, waste, and vent systems due to their lightweight, corrosion resistance, and ease of installation.

CPVC Pipes: Used for hot and cold water distribution, offering higher temperature resistance than standard PVC.

PEX Tubing: Flexible and durable, used for residential water supply lines, allowing for easy installation in complex layouts.

Thermosetting Plastics in Plumbing:

Epoxy Resins: Used for sealing joints and coatings on pipes, providing strong adhesion and resistance to chemicals and moisture.

Polyester Resins: Commonly used in the fabrication of plumbing fixtures, like sinks and bathtubs, due to their durability and finish.

Phenolic Resins: Utilized in the production of pipe fittings and valves, offering excellent heat resistance and structural integrity.

Multiple Choice

What is the primary use of PVC pipes in the plumbing industry?

• Electrical wiring

• Water supply and drainage

• Basins

• Sinks

Multiple Choice

Which of the following is a common type of plastic fitting used in plumbing?

• Copper elbow

• PVC coupling

• Steel flange

• Brass tee

Multiple Choice

How do plastic pipes impact the overall cost of plumbing installations?

• They increase the cost due to high material prices

• They have no impact on cost

• They reduce the cost due to lower material and installation expenses

• They increase the cost due to specialised tools required

Multiple Choice

What is a significant environmental concern associated with plastic plumbing materials?

• They are biodegradable

• Some are difficult to recycle

• They are more expensive than metal pipes

• They corrode easily

Multiple Choice

Which of the following is an advantage of using plastic pipes over metal pipes?

• Higher thermal conductivity

• Greater weight

• Resistance to corrosion

• Higher melting point

Multiple Choice

What is the typical lifespan of PVC pipes used in plumbing?

• 5-10 years

• 20-30 years

• 50-100 years

• 100-150 years

Multiple Choice

What is a common disadvantage of using plastic fittings in plumbing systems?

• They are prone to rust

• They can become brittle over time

• They are heavier than metal fittings

• They conduct electricity

Multiple Choice

How does the use of plastic pipes affect the thermal efficiency of a plumbing system?

• They improve thermal efficiency due to better insulation properties

• They decrease thermal efficiency due to high thermal conductivity

• They have no effect on thermal efficiency

• They require additional insulation to maintain efficiency

Multiple Choice

What is a key benefit of using plastic joints in plumbing systems?

• They require welding for installation

• They are more flexible and easier to install

• They are more expensive than metal joints

• They require specialised tools for installation