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The course you are attending is: PLUMBING AND GAS FITTING Sizing of consumer piping

Introduction to the Course Aims: To be able to size gas pipework correctly http://farm4.static.flickr.com

All must be installed to current standards and legislation Assessment criteria Locate, interpret and apply relevant information, standards and specifications to for the determination of requirements and the design of consumer piping systems Apply safety requirements throughout the work sequence, including the use of personal protective clothing and equipment As a minimum, from scaled plans/drawings, size consumer gas piping systems of at least one of them being a two stage LP gas system, ensuring: Correct identification of sizing requirements of proposed piping system Correct selection and use of appropriate processes, tools and equipment Completing all work to specification Compliance with regulations, standards and organisation quality procedures and processes. Communicate and work effectively and safely with others. All must be installed to current standards and legislation

Importance of correct pipe sizing The procedure set out is for pipe sizing specifically for Gas. This section deals with pipe sizing. As you maybe aware it is very important to achieve correct combustion at the appliance; this is achieved by having the correct amount of air/gas ratio. By making sure the pipe size is correct in the first place, you have a good chance of having the correct flow of gas. If you have an incorrectly sized gas pipe this could cause the appliance to be inefficient and therefore not meeting the customer’s expectations, and worse case scenario incomplete combustion causing CO. To avoid these situations we need to take into account the gross heat inputs of all appliances fitted on the system. There is an allowable pressure loss due to resistance within the pipe work this loss is dependent on type of tube and pressure available. Natural Gas appliances are designed to operate with an inlet pressure of 1.25KPa and LPG 2.75KPa

Information Required Prior To Pipe Sizing 1. The type of gas to be used in the installation, e.g. natural gas or LPG, 2. The gas consumption of each appliance in Megajoules per hour (MJ/h) 3. The operating pressure of the installation, e.g. 1.25 kPa or 2.75 kPa. 4. The maximum allowable pressure drop in the pipe work from the meter or cylinder outlet to any appliance. (See table below). 5. The proposed layout of the consumer piping system, including all pipe lengths, and the location of each appliance. Gas type Pressure drop Natural gas 0.12 kPa Low pressure gas 0.25 kPa Other gases 0.075 kPa Liquid petroleum gas 3.75 kPa TLP

Typical appliance sizes TYPICAL GAS RATES (MJ/HR)   WARM AIR HEATER 40 COOKER 40 MULTIPOINT WATER HEATER 100 GASFIRE/SPACEHEATER 20 STORAGE WATER HEATER 35

Method Of Pipe Sizing Step I. Sketch The Consumer Piping Layout Step 2. Mark The Position Of The Meter or Cylinders and Appliances showing gas consumption Step 3. Note The Length Of Each Pipe Section and Branch, rounded up to nearest metre, Step 4. Identify The Branch and Appliance Points and mark Use A, B, C, etc. Step 5. Determine The Main Run, see Next Slide

Information Required Prior To Pipe Sizing Step 6. Select the Pipe Material or Materials Step 7. Select the Pipe Sizing Table AS5601

AS5601

Water Heater Cooker 1m Fire 2m M 2m 4.5m 2m 2m

M Combi 1m 2m 1.5m 0.5m Storage water heater Cooker Fire Wall Heater Space Heater Space Heater