Trade of Plumbing Phase 2 Module 3 Unit

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Module 3: Domestic Heating/MMA Welding Unit 2 – Domestic Heating Systems Duration – 10 Hours

Trade of Plumbing – Phase 2 Module 3 – Unit 2 In unit 2 we learn how to: _Describe the working principles and types of domestic heating systems. _List the basic components of domestic heating systems and describe their function. _List common and alternative sources of heat energy. _Draw schematic representations of domestic heating systems.

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Key Learning Points _Rk _Rk _D _Rk _Sc _Rk _Rk _Sc _P _Rk _Rk _P Principles of domestic heating systems. Types of heating systems. Components of heating systems. Pipework layout. Drawing of domestic heating systems. Location and function of safety valves. Location and function of vent pipe, cold feed pipe. Primary flow and return pipework, cylinders. Gravity circulation. Fully pumped circulation. Function, location, components of circulation pumps. Types of radiators and radiator valves. Heat transfer in heating systems. Filling arrangement for sealed systems. Function, location, size of expansion vessel in sealed systems. Sources of heat energy, solid fuel, gas, oil. Alternative sources of energy Communication.

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Wet Central Heating Fire Extinguishers _Pipework Problems _Sealed Systems _Boiler Types

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Operator Protection _ No open-neck shirts; Ultra-violet rays will burn the skin. It is most definitely not similar to sun tanning. _ Regulation inflammable overalls only; Arc-welding produces large amounts of hot sparks which will set flammable clothing alight. _ No trainers/runners to be worn; The steel metal plate used are heavy and sharp. Wear steel toe-cap boots. _ Overalls not around waist; Sparks will set casual tops alight _ Always wear protective clothing; Arc-welding produces heat, glare, sparks, ultra-violet & infra-red rays and harmful fumes. Welding gauntlets must be worn at all times. Face masks are designed to deflect fumes and should therefore be held close to the face. Gas welding goggles will not afford protection for the face against the light intensity or the radiation and must not be used. Shade 11 EW filters are required in the face mask for manual metal arc welding. Always wear protective goggles when chipping slag.

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Basic Pipework Layouts Gravity Circuit

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Gravity Hot Water and Pumped Central Heating

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Fully Pumped DHW and CH System

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Cow Feed and Open Vent Positions

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Cold Feed and Open Vent

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Feed and Vent Pipes as Part of the Heating Circuit

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Close Coupled Systems

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Position of the Pump - Negative, Positive, Neutral

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Pump on Return

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Pump on Return/Cold Feed on Pump Inlet

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Fully Pumped System

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Open Vent as Part of the System

Trade of Plumbing – Phase 2 Module 3 – Unit 2 High Resistance Boiler

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Close Coupled System

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Removal of Air from the System

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Single Pipe Heating Circuits

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Two Pipe Heating Circuits

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Minibore or Microbore System

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Heat Emitters _Radiators _Convectors

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Radiator Controls _ Lockshield _ Customer Control

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Thermostatic Radiator Valve (TRV)

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Possible Radiator Problems _ Reverse Circulation

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Possible Radiator Problems. . continued _ Commoned Returns

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Sealed Or Pressurised Systems _ Typical Sealed System

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Expansion of Heated Water

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Interlinking of Solid Fuel to Automatic Boiler

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Pressure and Temperature Safeguards _ Pressure Release Valve & Discharge Pipe

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Filling and Maintaining the System Water _ Temporary Filling Loop

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Maintaining the Water Level _ Automatic Top Up Bottle

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Common Problems _ _ Temporary Filling Loop Checking and Recharging Expansion Vessels Overfilling a System Defective Expansion Vessel

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Domestic Central Heating Main Equipment The main equipment required in a domestic heating system consists of: _ A Boiler _ An Indirect Cylinder _ A Feed and Expansion Cistern or Expansion Vessel _ A Circulating Pump _ Radiators

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Domestic Central Heating Systems The are two main types of domestic central heating systems: _ The Open Vent System - This system incorporates a feed and expansion cistern, vent pipe, and cold feed. _ The Sealed System - In this system the expansion of water is taken up by an expansion vessel.

Trade of Plumbing – Phase 2 Module 3 – Unit 2 The Open Vent System The basic equipment in an open vent system: Feed & Expansion Cistern Indirect Hot Water Storage Cylinder Boiler

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Cold Feed to the Heating System Standard Gate Valve

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Primary Flow to the Cylinder

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Open Vent or Expansion Pipe

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Primary Return

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Radiators

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Radiator Valves Each radiator is fitted with two valves: _ A Handwheel valve on the flow _ A Lockshield valve on the return Handwheel Radiator Valve (Flow) Lockshield Radiator Valve (Return)

Trade of Plumbing – Phase 2 Module 3 – Unit 2 The One Pipe System of Central Heating Ring Main Circuit Flow Return

Trade of Plumbing – Phase 2 Module 3 – Unit 2 The One Pipe System of Central Heating

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Pump, Safety Valve, and Drain Cock Safety Valve Drain Pump

Trade of Plumbing – Phase 2 Module 3 – Unit 2 The Two Pipe Heating System of Central Heating Flow

Trade of Plumbing – Phase 2 Module 3 – Unit 2 The Two Pipe Heating System of Central Heating Return Flow Return

Trade of Plumbing – Phase 2 Module 3 – Unit 2 The One Pipe System of Central Heating Advantages: _ Only one pipe is necessary to convey hot water to the radiators _ Cheap to install Disadvantages: _ Hot water passing through the first radiator is cooled and returns to the main flow pipe _ This water then supplies the next radiator and has the effect of producing a lower temperature _ Only suitable for small single storey buildings

Trade of Plumbing – Phase 2 Module 3 – Unit 2 The Two Pipe System of Central Heating Advantages: _ Hot water from the boiler supplies each radiator and then returns via the return pipe without passing through any more heat exchanges _ Ensures a quick heat up time and a more positive flow to the radiators

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Radiators There are three main types of radiator: _ Panel _ Column _ Hospital Radiators can be manufactured from any of the following materials: _ Mild Steel _ Aluminium _ Cast Iron _ Copper

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Radiator Connections All radiators are threaded with female B. S. P. T. (British Standard Pipe Thread) connections. The location of the connections are: B. O. E. - Bottom Opposite End T. B. S. E. - Top and Bottom Same End T. B. O. E. - Top and Bottom Opposite End

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Radiator Valves _ The flow connection to a radiator should be fitted with a manually operated HAND WHEEL control valve _ The return connection should be fitted with a LOCKSHIELD radiator valve _ A Thermostatic Radiator Valve (TRV) is used to control the temperature of a radiator

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Positioning of Radiators _ Whenever possible, the radiator should be installed under a window _ If the radiator cannot be fitted under the window it should be on an adjacent wall _ The worst position is opposite the window as the convection currents will encourage the cold down flow of air

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Circulation Pumps _ These devices, sometimes known as accelerators, are fitted to the pipework to assist water circulation _ The pump is a very important part of the modern central heating system _ It enables the use of smaller diameter pipes and boilers than would be the case if a conventional gravity system was used _ The pump provides pressure inside the system which in turn forces water to circulate throughout the whole system of pipework and heat emitters _ The location of the pump within the system can be on the FLOW PIPE (now generally accepted as the best position) or on the RETURN PIPE

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Safety Valves _ It is essential that a safety valve is fitted in all heating installations _ Safety valves should be fitted directly on top of the boiler in the hottest part of the system with no intervening valve or restriction Safety Valve

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Safety Valve and Flow Pipe _ In the case of solid fuel wrap around boilers the previous arrangement may not be possible and the usual practise is to fit the safety valve on the FLOW PIPE as near as is practical to the boiler _ The safety valve should always be accessible for testing Safety Valve Flow Pipe

Trade of Plumbing – Phase 2 Module 3 – Unit 2 The Sealed System of Central Heating In the sealed system the water is supplied from either: _ The Incoming Water Main _ A Top Up Bottle When filling the system from the incoming water main a “FILLER LOOP” may be used. This is a device which incorporates: _ A Check Valve (Non-Return Valve) _ An Isolating Valve _ A Flexible Pipe For Disconnecting

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Expansion Vessel _ An expansion vessel is a gas/air filled vessel used to take up the expansion of water in sealed central heating systems _ The gas or air is separated from the system water by a rubber diaphragm or washer _ The vessel is charged with gas or air equal to the static head of the system _ In a domestic situation this pressure should never exceed 1 bar _ In a domestic central heating system the water temperature should never exceed 80ºC

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Sealed System of Central Heating with Top Up Bottle NRV AAV Safety Valve Drain Gauge Sealed Expansion Vessel

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Sealed System of Central Heating with Filler Loop AAV Safety Valve Drain Gauge Sealed Expansion Vessel Double Check Valve and Temporary Connection

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Sizing of Expansion Vessels System Load Size of Vessel Internal Gas Pressure Safety Valve Pressure (k. W) (Litres) (Bar) 3 4 0. 5 – 1. 0 3 6 4 0. 5 – 1. 0 3 12 8 0. 5 – 1. 0 3 18 12 0. 5 – 1. 0 3 24 18 0. 5 – 1. 0 3

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Advantages of the Sealed System _ There is no loss of water through evaporation because there is no F&E cistern, and therefore there is less risk of oxygen entering the system _ The vessel can be located close to the boiler and therefore monitored on a regular basis _ Pumping over or pitching into the F&E cistern is eliminated _ The boiler can be located anywhere in the installation _ In industrial situations the system can be operated at high temperatures _ There is a cost saving in time and material due to the elimination of pipework to the F&E cistern _ The danger of frozen pipework is greatly reduced because there may be no pipes in the attic

Trade of Plumbing – Phase 2 Module 3 – Unit 2 The Sealed System in Industrial Installations _ In systems which need to be designed to operate at or over 100ºC, the pressures must be higher than 1 bar _ In large installations where excessively long pipe runs are common, and the criteria for domestic situations were applied (i. e. max. water temperature of 80ºC), the temperature drop over the long run could be such as to make it impossible to achieve the required heat output _ A “PRESSURISED” sealed system is used to overcome this difficulty _ The higher the internal pressure of the system the higher the temperature of the circulating water

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Automatic Air Vents An automatic air vent is a valve designed to release air automatically from the high point of a central heating system Automatic Air Vent Return Flow

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Commissioning of Wet Central Heating Systems _ The pump should be removed and replaced with a suitable piece of pipe to bridge the gap _ The system should then be drained down and receive a flush through to remove any wire wool, flax, PTFE tape, flux, solder, etc. _ At this stage the boiler can be commissioned for correct operation _ Close all lockshield valves and go round the system balancing the heat emitters to each room _ Check the operation of the programmer, room thermostat, and cylinder thermostats, etc. _ Recheck for leaks _ Refill and vent the system, adding an inhibitor, if applicable

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Handing Over _ The working of the system should be demonstrated to the user and the best methods of economic and efficient usage explained _ All documentation supplied with equipment should be left with the owner/occupier

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Identification of Circulating Pumps Impeller Stator Rotor Windings

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Assembling Oil Fired Boilers Flue Flow 1. Adjustable boiler thermostat 2. Oil pump 3. Ignition transformer 4. Solenoid valve 5. Photo electric cell 6. Boiler limit thermostat 7. Temperature gauge 8. Burner motor and fan 9. Nozzle 10. Ignition electrodes Cleaning Door 11. Burner control box Waterways Fire Brick Return

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Assembling Oil Fired Boilers 1. Reset button 2. Control box 3. Ignition transformer 4. Ignition cables 5. Nozzle assembly 6. Nozzle 7. Brake plates 8. Blast tubes 9. Ignition electrodes 10. Connecting pipe 11. Air damper 12. Solenoid valve 13. Pump 14. Drive coupling 15. Indication, air damper 16. Fan wheel 17. Adjustment, air damper 18. Photoresistor 19. Motor

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Radiator Identification B. O. E T. B. O. E IN OUT T. B. S. E Double Panel Single Panel Treble Panel High Output

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Types of Radiator Wall Radiator Classic Wall Radiator Hospital Radiator Royal Radiator Narrow Pattern Hospital Radiator

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Fitting of Expansion Vessels Water Connection Air or Gas When the heating is cold, the air or gas charge completely fills the vessel Air or Gas Valve Water When the system starts to heat up, the expanding water begins to compress the air or gas charge Water When the system is at full temperature, the water has reached its maximum expansion and the air or gas charge is fully compressed

Trade of Plumbing – Phase 2 Module 3 – Unit 2 Expansion Copper Cylinder Identification Hot water supply Expansion pipe leveled off to prevent one pipe circulation Expansion connection Gate valve Drain cock Cold feed connection Copper cylinder heated by immersion only Indirect cylinder with immersion heater Copper cylinder with immersion heater Twin coil indirect cylinder with immersion heater