Cold Water Storage Cisterns

Question 0

Define a cold water storage cistern? (Cwsc)

Answer 0

It is defined as an open topped vessel designed to hold a supply of cold water.

Question 1

What is the name given too a vessel used to store cold water in the attic?

Answer 1

Cold water storage cistern

Question 2

Should it ideally be fitted at high or low level? Give a reason for your answer

Answer 2

It should be fixed as high as possible to give adequate pressure flow

Question 3

List 3 materials used it the manufacture of cold storage cisterns?

Answer 3

Galvanised mild steel
Plastic materials
Glass fibre sections

Question 4

List 3 reasons for fitting a cover on a cold water storage cistern?

Answer 4

To prevent the access of dirt, dust, vermin or light

Question 5

Is it ok to fit a wooden cover?? Explain your answer

Answer 5

Wooden covers are not ideal as wet rot can occur and a tight fit is not possible

Question 6

Should you drink the water from a cold water storage cistern?

Answer 6

No you can’t due to the possibility of stagnation

Question 7

Give 3 reasons why the cold water storage cistern should be insulated?

Answer 7

1) Water could freeze in cold weather
2) if the water gets too cold it will require more energy too raise the temp of this water in the hot water cylinder it supplies
3) in hot weather the water can become too warm and allow the multiplication of bacteria

Question 8

What is the purpose of screening vents?

Answer 8

the purpose of screening vents are to stop dirt particles getting inside the cistern

Question 9

What is galvanising of cold water storage cisterns?

Answer 9

When it is dipped into zinc

Question 10

List two methods of good practise that can prolong the life of a galvanised cold water storage cistern?

Answer 10

Removing the swarf and spreading two coats of good quality bituminous paint on the inside of the cisterns

Question 11

Give 3 advantages of using plastic cold water storage cisterns over galvanised?

Answer 11

They are strong and resistant to corrosion
Virtually ever lasting
Very light in weight

Question 12

Is it ok too cut holes in plastic cisterns using hot pipework?

Answer 12

No because it will lead to failure around the joint

Question 13

Can jointing compound be used on plastic cisterns? Give an example for your answer?

Answer 13

No because it softens the materials and makes it break down

Question 14

What is a suitable material for jointing to a polythene cistern?

Answer 14

Plastic washers

Question 15

Why are plastic cisterns black?

Answer 15

Too prevent algae growth

Question 16

How are holes cut in a plastic cold water storage cistern?

Answer 16

They are drilled with a holesaw

Question 17

Can boss White be used on a polythene cistern?

Answer 17

No it cannot

Question 18

We’re are glass fibre cisterns used?

Answer 18

We’re more amounts of water is able too be stored like hotels

Question 19

What is the actual capacity of a cold water storage cistern?

Answer 19

The actual capacity refers to the amount of water measured from the base of the cistern up to the water line.

Question 20

What is the nominal capacity of a cold water storage cistern?

Answer 20

The nominal capacity indicates the amount of water it would hold if filled up too the top edge.

Question 21

What is the usable capacity of a cold water storage cistern?

Answer 21

The usable capacity is the amount of water which can be drawn off through the distribution pipe connections.

Question 22

What is the approximate weight of a polythene cistern with an actual capacity of 500 litres?

Answer 22

Half a ton

Question 23

Where should the ball valve be fitted on a cold water storage cistern? Give reason for your answer?

Answer 23

Ball valves should be fitted as high as possible to gain the maximum storage of water

Question 24

What is the purpose of an overflow pipe?

Answer 24

The purpose of an overflow pipe is too prevent floods

Question 25

Where should the overflow pipe be fitted on a cold water storage cistern? Give reason for your answer?

Answer 25

It should be located 40mm below the ball valve connection to ensure the ball valve will never become submerged

Question 26

We're should the cold distribution be fitted on a cold water storage cistern? Give a reason for your answer?

Answer 26

65mm from the bottom of the cistern and to prevent possible scalding in the event of mains failure

Question 27

Where should the feed too the cylinder be fitted on a cold water storage cistern?

Answer 27

It should be fitted just above the cold water feed

Question 28

What size should an overflow pipe be?

Answer 28

It should be one size larger than the cistern supply pipe

Question 29

Why is the ball valve sites 40mm above the overflow?

Answer 29

If it becomes in contact with the overflow it can cause back siphonage

Question 30

What is the purpose of a ball valve backplate?

Answer 30

It is used to protect the cistern wall from fatigue

Question 31

How should two or more cisterns be connected?

Answer 31

When connecting two or more cisterns each cistern must have a mains water inlet to prevent the top layer becoming stagnant each cistern must have an overflow and an opposite side exit on each cistern

Question 32

How is stagnation prevented on a single cold water storage?

Answer 32

All cisterns should be installed to best practise to prevent stagnation