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L2 Plumbing Unit 4 Apply scientific principles within mechanical services engineering

Unit 4: Activity Sheet 4.2

Plumbing materials

Tutor guidance notes

Aims and objectives

At the end of activities 4.2A and 4.2B, learners should be able to:

● state the main standards covering materials● list the materials used for pipes, fittings and components● visually identify and name the materials used for pipes, fittings and components● describe the general properties of materials● explain the various categories of materials● specify the correct types of materials for particular applications● state the methods of protecting materials from damage.

The activity is divided into two parts: a set of questions (activity 4.2A) followed by a multiple-choice exercise (activity 4.2B). They are not intended as formal assessment. However, the answers should be discussed with learners as a group to ensure they fully understand the topic.

The activity can be used in different ways, for example:

● during the session, either individually or in pairs, as a ‘to-the-point’ learning tool● at the end of a session to recap learning● as homework.

Activity 4.2B could be used at the beginning of a subsequent session to link with prior learning.

Whichever teaching method is chosen, it is advisable to set and agree a completion date for each activity.

© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.1


Unit 4: Activity Sheet 4.2

Activity 4.2A Plumbing materials

Answer the following questions.

1 Write in your own words why the plumbing industry needs to haveagreed standards.

Without agreed standards it would be difficult to know the quality of

materials and size of pipes and fittings, which could be different from

one manufacturer to another, making it very difficult to install systems.

2 a Draw the BSI kitemark.

b List the name and number of British Standards that are linked to plumbing.

Examples include: BS 6700 Hot - and cold - water services; BS 1212

Float-operated valves; BS 1566 Manufacturing of copper cylinders;

BS 1010 Taps and fittings for hot and cold water.

Learners may suggest others.

3 What are Approved Codes of Practice (ACoPs)?

An Approved Code of Practice (ACoP) offers practical examples of good

practice to help businesses comply with legislation and is developed after

consultation with the industry concerned. ACoPs are widely used by

specifiers , such as clients and architects. Failure to follow an ACoP is

not an offence.



4 Which regulations cover water run to people’s homes, and the materials that come into contact with that water?

The Water Supply (Water Fittings) Regulations 1999

5 Explain the difference between BS and EN standards?

BS is a standard set by the British Standards Institution (BSI), the

organisation for standards in the UK. A product that is certified to an

EN standard will have been through a series of tests that are regularly

checked under the EC (European) Quality Control scheme.

6 What is the role of the Water Regulations Advisory Scheme (WRAS) and what does it provide as an aid to plumbers?

WRAS tests fittings and produces a Water Fittings and Materials

Directory, which lists all approved fittings to enable plumbers to

comply with the Water Regulations.

7 The Water Supply (Water Fittings) Regulations 1999 cover the materials that come into contact with drinking water. List the various materials plumbers can use and give examples of where you could use them.

Examples include: copper pipe – hot - and cold - water systems; plastic

pipe – hot - and cold - water systems; brass–pipe fittings; bronze –

corrosion-resistant pumps, underground water pipe; stainless-steel

– hot - and cold - water supply pipes. Learners may suggest others.

Learners may suggest others.

8 The materials you listed in your answer to question 7 have a range of different properties. Which is the most essential property?

All are resistant to corrosion.

9 Explain in your own words the mechanical properties of the following terms:

Hardness:

A measure of a material’s resistance to permanent or plastic deformation

by scratching or indentation.

Strength:

The extent to which a material can withstand an applied force or load

(stress) without breaking.



Elasticity:

The ability of a material to be stretched and return to its normal shape.

10 Draw a line matching each of the properties below to its definition.

Property Definition

11 Practical demonstration: Your tutor will show you a selection of pipes, fittings and components made from various materials. Your task is to group them together. It is easy to group them as either metal or plastic but try to differentiate between different metals or a reasonably pure material and an alloy.

12 a What do R250 and R220 mean?

R250 half hard (also called Table X) is the copper tube most commonly

used above ground for plumbing and heating installations; R220 soft

coil (also called Table Y) is a softer copper tube, which is most

commonly used underground for the supply of water.


Tenacity

Malleability

Durability

Plasticity

Thermal expansion

Temper

Fusibility

The exact opposite of elasticity – a material that does not return to its

original shape when deformed.

The ability of a material to withstand distortion without fracture, such as metal

that can be drawn out into a fine wire.

The degree of hardness in a metal.

The melting point of a material, i.e. when a solid changes to a liquid.

The ability of a metal to be worked without fracture.

The material’s ability to resist wear and tear.

A material’s ability to resist being pulled apart.

Ductility

The amount a material expands when heated.


b What do Table W and Table Z mean?

Table W is soft coil copper used for micro-bore pipe work; Table Z

is R290 hard copper tube and cannot easily be bent.

13 a What is the other name for low carbon steel?

Mild steel

b Low carbon steel is available in three grades: light, medium and heavy. How can you tell on site which grade you have?

Light LCS tube has thin walls, a large bore and is colour coded brown;

medium LCS tube has medium walls, a medium bore and is colour coded

blue; heavy LCS tube has thick walls, a small bore and is colour

coded red.

14 Complete the table below by filling in the percentages of each element that makes up stainless steel, and naming the trace elements.

Element Percentage in stainless steel (%)

Iron 70 (approx)

Chromium 18

Nickel 10

Manganese 1.25

Silicon 0.6

Carbon 0.08

Sulfur TracePhosphorus Trace

15 a What should you do if you find lead pipework in a property? Why?

Report it to your supervisor as it could cause lead poisoning.

b Which regulations stopped the practice of using lead pipe, and which regulations must you adhere to if you find lead pipe in a building?

The Model Water Bye-laws 1986 stopped the practice of using lead

pipe. The Water Supply (Water Fittings) Regulations 1999 (the

Water Regulations) have superseded the Bye-laws.

16 Where might you come across cast iron?

In above- and below-ground sanitary pipework.



17 What is a compound?

A mixture of two or more elements.

18 Complete the table below with the name of the metal most suitable for use in each of the situations.

Situation Metal

Exposed pipework in commercial kitchens, where ease of cleaning and strength are crucial

Stainless steel

Tubes for conveyance of gas or water Copper

Sanitary ware in public buildings, where strength is needed

Cast iron

Rigid tube for above ground micro-bore pipework R290 hard copper pipe

Water supply services in domestic premises, where high pressure is involved

Galvanised low carbon steel

19 Categorising plastics is more difficult than categorising metals. Explain the following terms:

Plastic Explanation

Thermosetting plastics

Used for mouldings. They soften when first heated, which enables them to be moulded. They set hard when they cool and their shape is fixed.

Thermoplastics Can be re-softened by heating.

20 Practical demonstration: Your tutor showed you some pipes made of thermoplastics. Look at them again and decide which pipe is made from which type of plastic. Your tutor will explain where you may use each type.

21 Where might thermosetting plastics be used in plumbing systems?

WC cisterns

22 Where might ceramics be used in plumbing systems?

Wash hand basin, sink, etc.

(Note: learners may need to think this answer through from knowing that ceramics produce earthenware pottery and china.)

23 Damage caused to materials can be expensive in terms of replacement costs and time spent seeking replacements. Describe the procedures and safe-site practices that will help protect materials from damage.

Protective coatings, such as plastic and galvanised coatings, are put

around materials to prevent corrosion.



Activity 4.2B Plumbing materialsCircle the correct answer in each of the questions below.

1 What does the abbreviation WRAS stand for?

a Water Rules and Specifications

b Well Regulations and Supply

c Water Regulatory Action Standards

d Water Regulations Advisory Scheme

2 Lead is a very ‘malleable’ metal. What does malleable mean?

a It has a high melting point.

b It is easily worked without fracture.

c It can be drawn out to form wire without fracture.

d It resists being pulled apart.

3 Which metal is used to galvanise low carbon steel?

a Zinc

b Chrome

c Nickel

d Boron

4 Which type of plastic is used most frequently in the manufactureof plumbing materials?

a Thermoplastic

b Thermosetting

c Technoplastic

d Technosetting



5 The following statement describes a thermoplastic and what it is suitable for: ‘Tough plastic with a relatively high melting temperature – it can be used to channel boiling water for short periods of time.’ Which thermoplastic does the statement apply to?

a Polythene

b u-PVC

c Polypropylene

d Polystyrene

6 This material is made from sand and calcium carbonate, what is it?

a China

b Plastic

c Glass

d Low carbon steel

7 What is brass made from?

a Copper and tin

b Copper and zinc

c Copper and lead

d Copper and magnesium

8 What is bronze made from?

a Copper and tin

b Copper and zinc

c Copper and lead

d Copper and magnesium


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