3B Components of Domestic Cold Water Systems

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What minimum height should a Cold Water Storage Cistern be installed above the top access for maintenance purposes?

400mm

350mm (correct)

300mm

250mm

Which materials are commonly used for making Cold Water Storage Cisterns?

Plastic, Fiber Glass, Asbestos, and Galvanized Steel (correct)

Fiber Glass, Wood, Stainless Steel, and Asbestos

Aluminum, Steel, Concrete, and Plastic

Wood, Fiber Glass, Plastic, and Copper

What is the primary purpose of the effective inlet control in a Cold Water Storage Cistern?

To filter contaminants

To maintain the correct water level (correct)

To regulate water temperature

To prevent loss of water

Which of the following statements best describes the role of a screened warning/overflow pipe?

It prevents insects and light from contaminating water Signup and view all the answers

What is the purpose of the cold feed in a Cold Water Storage Cistern system?

To supply cold water to the hot water cylinder Signup and view all the answers

Which installation step minimizes the risk of water stagnation in a Cold Water Storage Cistern?

Arranging for adequate circulation of water Signup and view all the answers

What is the minimum size of the cold feed and cold distribution pipes in a Cold Water Storage Cistern system?

22mm Signup and view all the answers

Why should a fullway gate valve be fitted to the cold feed or distribution in a Cold Water Storage Cistern?

To allow for pipework isolation Signup and view all the answers

What is the primary function of a warning pipe in a cistern system?

To indicate a problem with the cistern Signup and view all the answers

Which of the following insulation materials is NOT mentioned as suitable for cisterns?

Wood shavings Signup and view all the answers

For cisterns with a capacity below 1,000 litres, what is required regarding warning and overflow pipes?

Only a warning pipe is needed Signup and view all the answers

What essential action should be taken when drilling a flexible cistern?

Use a hole saw to drill the hole Signup and view all the answers

When two or more cisterns are linked together, what states that the float operated valve and warning pipe should be in the same cistern?

BS EN 806 Signup and view all the answers

What issue can stagnant water in a cistern lead to?

Mold growth and contamination Signup and view all the answers

What is the function of a float operated valve in a cistern?

To keep water levels constant by regulating flow Signup and view all the answers

What should be avoided when using jointing materials in relation to a plastic cistern?

Jointing materials containing oil Signup and view all the answers

What is the legal requirement for plumbers in the UK regarding materials and fittings?

They must use approved materials, fittings, and appliances. Signup and view all the answers

Which isolation valve is commonly used on the incoming mains?

Screw down stop valve Signup and view all the answers

What type of valve is specifically required prior to a float operated valve on certain appliances?

Service valve (slotted) Signup and view all the answers

What is one feature of a Fullway gate valve?

Can have a lock shield fitted. Signup and view all the answers

What does Surestop provide as a solution for water isolation?

An air/water pressure mains isolation system. Signup and view all the answers

Where should a drain off valve be installed in a water system?

At every low point in the system. Signup and view all the answers

Which type of tap maintains a watertight seal by using a packing gland and a fibre washer?

Rising spindle tap Signup and view all the answers

What is the primary feature of a bi-flow mixer tap?

It has two taps in one body. Signup and view all the answers

Which valve can be used for both high and low pressure applications?

Lever arm spherical plug valve Signup and view all the answers

What is the purpose of a service valve (slotted)?

To isolate and control water flow before appliances. Signup and view all the answers

Which of the following is necessary for the correct functioning of a mixer tap?

Equal pressure systems Signup and view all the answers

What distinguishes a non-rising spindle tap from other types?

The tap washer is attached to a moving barrel. Signup and view all the answers

What type of water supply is appropriate for a true mixer tap?

Mixed supply from both hot and cold sources Signup and view all the answers

What feature makes quarter turn taps particularly suitable for less abled people?

They require less force to operate. Signup and view all the answers

Which type of tap uses O-rings for maintaining the watertight seal?

Non-rising spindle tap Signup and view all the answers

What application is specifically associated with bib taps?

Attaching to a wall above a cleaner’s sink Signup and view all the answers

What is the primary function of the float operated valve BS1212 part 1?

Water discharges from the bottom. Signup and view all the answers

Which material is used for the float operated valve BS1212 part 2?

Brass Signup and view all the answers

What can be used to reduce water hammer when using a float operated valve?

Use pressure and flow restrictors. Signup and view all the answers

What characteristic differentiates float operated valves BS1212 part 3 from part 2?

Part 3 is made of plastic. Signup and view all the answers

What is a potential cause of water hammer in a plumbing system?

Loose jumper in a stopcock. Signup and view all the answers

How does the equilibrium diaphragm valve type BS1212 part 4 function?

It allows equal water pressure on both sides of the diaphragm. Signup and view all the answers

What adjustment method is used for the water level in float operated valves BS1212 part 2 and 3?

Bending the float arm. Signup and view all the answers

Which of the following statements regarding float operated valves is incorrect?

Solid silencers are allowed in part 2. Signup and view all the answers

Study Notes

Components Used in Domestic Cold Water

Domestic cold water systems use various components, including isolation valves, taps, and cold water storage cisterns.
Different types of isolation valves are used for different purposes.
Screw down stop valves are typically used on incoming mains (high pressure) and have a specific flow direction.
Service valves (slotted) can handle high or low pressure and are placed before float operated valves on certain appliances, with a determined flow direction.
Washing machine valves connect before washing machine hoses.
Lever arm spherical plug valves handle high or low pressure, following a specific flow direction.
Fullway gate valves function only with low pressure systems, similarly to other valves with lock shields to prevent tampering.

Lesson Intent

Students will identify various components and describe the use of specific isolation valves.
Students will be able to distinguish different tap types and write short descriptions.
Students will provide a list of cold water storage cistern parts.
Students will explain the differences between float-operated valves and their uses.

Legal Requirements

UK plumbers are legally obligated to utilize approved materials, fittings, and appliances.
WRAS (Water Regulations Approval Scheme) standards ensure that used products meet necessary safety, quality and performance standards.
Approved products prevent backflow contamination and corrosion in water systems.

Isolation Valves

Screw down stop valves: Employed on incoming mains, high-pressure systems, and have a stated flow direction.
Service valves (slotted): Can operate with high or low pressure; they're typically fitted before float valves for specific appliances with a clear flow direction.
Washing machine valves: These are installed prior to the washing machine hose attachment.

Isolation Valves (continued)

Lever arm spherical plug valves: Suitable for high or low pressure, with a specific flow direction.
Fullway gate valves: Specific to low-pressure systems, and like other valves, they can have lock shields to prevent tampering or misuse.

Activity 1: Labeling Valves

Images show various valve types (washing machine valve, tap connector isolation valve, lever valve, fullway gate valve).
Students should correctly identify and label each valve.

Surestop

Surestop is a modern main isolation system.
This system uses air/water pressure.
A solenoid type system serves as an emergency isolation valve for possible leaks.
A manual valve should be employed upstream in the system for component failures, and the system might be wired to a control system.

Surestop (continued)

Brass stopcocks often are in inconvenient areas.
Surestop remote stopcocks provide a simple method for turning off water up to two meters away.
Easy installation and water pressure makes it effective.

Drain Off Valve

Drain off valves should be installed at every low point of a water system.
These valves are positioned directly above the incoming stop valve, permitting the safe removal of water.

Screw Down (high pressure) and Fullway (low pressure)

Diagrams display the internal workings of both valves.
Detailed explanations of components (e.g., tap wheel head, rising spindle, packing gland, packing, head workings, jumper and washer for screw down) can be found alongside descriptive labels for their respective components (e.g., wheel head, packing gland, packing, non-rising spindle, rising gate, and olive compression fitting for fullway).

Isolation Valves (Questions)

Students can answer questions regarding types of isolation valves.
Questions can include identification of screw-down stop valve, spherical plug valve, slotted service valve, and gate valve configurations.

Pillars Taps

Pillar taps primarily serve baths, basins, and bidets.
Baths use ¾" BSP tails with 22mm pipes.
Basins and bidets use ½" BSP tails with 15 mm pipes.

High Neck Pillar Taps

High neck pillar taps are specifically designed for use on kitchen sinks.
Taps have a similar look to standard pillar taps, having a larger air gap provided via a longer neck.
A ½" BSP tail is attached to a 15mm pipe for drainage/supply.

Bi-Flow Mixer Tap

Known as a mono-block, bi-flow tap has two taps in a single body.
A single spout divides water flow but allows for independent flow from either tap.
They mix the water flow after leaving the taps only.
These are designed for use on baths, basins, and bidets.

Mixer Tap

True mixer taps combine hot and cold water within their body for mixing.
They are suitable for sinks and baths where equal pressure from hot and cold sources is ideal.
In specific circumstances, they can need specialized installation based on equal pressure system requirements.

Bib Taps

Bib taps require a back plate elbow for wall-mounted installations.
These taps are fitted over sink areas, and in some cases, the tap is outside.

Tap Types

Taps are categorized into three main types, with varying configurations relating to the positioning of the spindle and handle.
These three types contain a rising spindle tap, a non-rising spindle tap, and a quarter-turn tap.
The identification, and in some cases a diagram, of the different components can be found in the respective sections above (spindle tap, non-rising tap, and quarter-turn tap).

Cold Water Storage Cistern

Cold water storage cisterns must meet water regulation standards, offering wholesomeness, cleanliness, and prevention of contaminants.
Piping and control mechanisms should be situated to prevent stagnation and offer accessibility for cleaning and maintenance, following manufacturer guidelines.

Cold Water Storage Cistern (continued)

Cold water storage cisterns are made of materials such as plastic, fibreglass, asbestos, and galvanized steel.
Cisterns should have a minimum of 350mm clearance above the top access point, facilitating maintenance.
Cisterns under and over 1000 liters need either a single warning pipe or a separate warning/overflow pipe, ensuring there is an audible warning for any problems.

Drilling Cisterns

Flexible cisterns need hole saws for drilling.
Avoid heating copper pipes and using oil-based materials when working with plastic cisterns, as either of these can lead to leakage.

Multiple Cisterns

Where two or more cisterns are interconnected, the water regulations and BS EN 806 state that all float operated valves and warning pipes should be in the same cistern.
Stagnation issues are important factors to consider; if separate cisterns interconnect, a separate connecting pipe is necessary to the subsequent cistern.

Stagnation

Stagnation is a potential issue in a single cistern.
To avoid this problem, install the primary outlet on the opposite side to the float-operated valve for optimal flow and prevention of stagnant water.

Incorrect/Correct Cisterns

Images depict scenarios with incorrect installations (e.g., issues with water pooling in cisterns below, lack of adequate support).
Contrasting images suggest correct installations (e.g., well-supported cisterns in lofts with adequate spacing).

Float Operated Valves

A float-operated valve shuts off the water supply to a cistern at a specified level.
It operates on a lever system, where the valve opens when the float is in the lower position.
As water fills the cistern, the float rises and slowly closes the valve.

Float Operated Valves (continued)

Different types of float-operated valves (e.g., Portsmouth valve, diaphragm valve) are defined in given information.
These different types have varying outlet configurations (bottom or top, depending on the design/type).

Water Hammer

Water hammer is a common issue with water pipes that are subjected to high pressure.
Some causes of water hammer include loose jumpers, improper pipe installation, and certain valve configurations.
Specific types of water hammer problems arise from partially blocked valves or insufficient supports and stiffeners.

System Maintenance

Maintaining valves is crucial for proper cistern functionality.
Periodic inspections ensure the water levels are correct.
Maintaining proper flow of water is vital to the efficiency and function of the plumbing system.

Test Your Knowledge (Questions)

Questions covering the functionality and installation of diverse types of valves, taps, cisterns and other elements are included.
Questions are provided about the function of the valve, its location, and its pressure requirements.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz focuses on the various components used in domestic cold water systems, including isolation valves, taps, and storage cisterns. Students will learn to identify the functions of different types of valves and their applications in plumbing. Key concepts include flow direction and pressure handling.