Presentation is loading. Please wait.

Presentation is loading. Please wait.

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

Similar presentations


Presentation on theme: "Trade of Plumbing – Phase 2 Module 3 – Unit 2 Module 3: Domestic Heating/MMA Welding Unit 2 – Domestic Heating Systems Duration – 10 Hours."— Presentation transcript:

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

2 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.

3 Trade of Plumbing – Phase 2 Module 3 – Unit 2 Key Learning Points  Rk Principles of domestic heating systems.  Rk Types of heating systems.  Rk Components of heating systems.  RkPipework layout.  D Drawing of domestic heating systems.  Rk Location and function of safety valves. Location and function of vent pipe, cold feed pipe.  RkPrimary flow and return pipework, cylinders.  ScGravity circulation.  RkFully pumped circulation.  RkFunction, location, components of circulation pumps.  RkTypes of radiators and radiator valves.  ScHeat transfer in heating systems.  PFilling arrangement for sealed systems.  RkFunction, location, size of expansion vessel in sealed systems.  RkSources of heat energy, solid fuel, gas, oil.  RkAlternative sources of energy  PCommunication.

4 Trade of Plumbing – Phase 2 Module 3 – Unit 2 Wet Central Heating Fire Extinguishers  Pipework Problems  Sealed Systems  Boiler Types

5 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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

24 Trade of Plumbing – Phase 2 Module 3 – Unit 2 Heat Emitters  Radiators  Convectors

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

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

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

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

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

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

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

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

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

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

35 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

36 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

37 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.

38 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

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

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

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

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

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

44 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)

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

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

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

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

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

50 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

51 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

52 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

53 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.O.E. - Top and Bottom Opposite End T.B.S.E. - Top and Bottom Same End

54 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

55 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

56 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

57 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

58 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

59 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

60 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

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

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

63 Trade of Plumbing – Phase 2 Module 3 – Unit 2 Sizing of Expansion Vessels System LoadSize of VesselInternal Gas PressureSafety Valve Pressure (kW)(Litres)(Bar)(Bar) – – – – – 1.03

64 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

65 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

66 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 Flow Return

67 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

68 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

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

70 Trade of Plumbing – Phase 2 Module 3 – Unit 2 Assembling Oil Fired Boilers Flow Flue Cleaning Door Waterways Fire Brick Return 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 11.Burner control box

71 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

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

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

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

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


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

Similar presentations


Ads by Google