Thermal Expansion in Plumbing

Which metal is more cathodic than iron in the electromotive series?

• Zinc

• Lead

• Tin

• Cadmium

Which components are protected by the sacrificial anode in a hot water cylinder?

• Plastic components

• Steel components

• Rubber components

• Glass components

What happens to brass fittings when zinc is leached out?

• They become stronger

• They become weak and brittle

• They change color to blue

• They become magnetic

What is the role of zinc in the galvanising process?

• To add color

• To prevent oxygen from reaching the ferrous material

• To make the metal heavier

• To increase electrical conductivity

What is the base metal commonly used in chrome plating and galvanising?

• Aluminum

• Steel or brass

• Gold

• Silver

What is the main benefit of galvanising?

• It makes metals shiny

• It prevents corrosion

• It increases flexibility

• It reduces weight

What does a galvanised coating protect LCS from?

• Heat

• Water pressure

• Environment and oxygen

• Electrical interference

What is the lifespan of Denso tape protection for LCS pipes?

• 5 years

• 10 years

• 15 years

• 20 years

What type of maintenance is required for painted cast iron guttering?

• Occasional

• Regular

• Annual

• None

How does painting help in maintaining plumbing systems?

• By increasing water pressure

• By protecting from atmospheric corrosion

• By reducing pipe diameter

• By enhancing thermal insulation