Gas supply sizing (meter and pipe)

posted in: Help guides
Will my new wok cooker work on my existing gas pipe? Is my gas meter big enough?

 

How much cooking equipment can I connect to my gas pipe?
How big does my gas meter and pipework need to be for my new restaurant/takeaway kitchen layout?

 

Who should I contact to install or upgrade my site’s gas supply?

This guide will help you plan a new commercial kitchen or replacements of catering equipment by estimating the capacity of an existing gas supply (both the gas meter and internal pipework), what capacity is required for the gas appliances and cookline you want, and then how to get a new or upgraded gas connection if needed. For new installations start with “Calculating gas loading” kW and then work backwards to see the minimum size pipe and meter required. Undersized gas pipe and supplies can cause improper combustion that is considered Immediately Dangerous (ID) and would stop you from operating the kitchen.

Size and capacity of gas meters

If there is an existing gas meter, you can easily establish the capacity from the small print somewhere near the meter’s readout, stated in cubic feet (ft3/h) or cubic meters (m3/h) per hour. Red outlined on the photo is an example on a modern U6 domestic meter.

U6 domestic, marked as Qmax=6m3/h or 212ft3/h. 64 kW maximum typical capacity.
U16, marked as Qmax=16m3/h or 565ft3/h. 172 kW maximum typical capacity. This is generally the minimum size needed for a commercial kitchen.
U25, marked as Qmax=25m3/h or 883ft3/h. 268 kW maximum typical capacity.
U40, marked as Qmax=40m3/h. 430 kW maximum typical capacity.

Remember: actual capacity in the kitchen can be limited by your internal gas pipes, you should complete that section too


Calculating gas loading

Add up the existing load, and/or proposed load in kW. Each appliance should have a data plate or specification sheet that will state its power (in kW, if you see BTU convert to kW by dividing by 3412). Because dataplates can be difficult to access or you may not have finalised your gas catering equipment choices, we have a handy table of typical values for catering equipment you can use to estimate. Remember to include boilers that may be in other rooms.

Appliance type Gas power (loading)
Boiler (heating or combi) 25-42 kW
Chargrill (600 width) 16 kW
Combi steaming oven (gas 10 grid) 22 kW
Duck roast oven 16 kW
Fryer (300 wide medium duty) 9 kW
Fryer (500 wide heavy duty) 28 kW
Griddle (600 wide) 9 kW
Appliance type Gas power (loading)
Range (4 burner) with oven 30 kW
Range (6 burner) with oven 42 kW
Salamander grill (wall) 6 kW
Steamer (dim sum atmospheric) 35 kW
Stockpot range (single) 37 kW
Wok burner (front, each) 19 kW
Wok burner (rear, each) 11 kW
Wok burner (turbo, each) 34 kW

Size and capacity of internal gas pipes

The below table gives the circumferences (the distance around the outside) of common gas pipe sizes, and their capacity (kW). You can measure circumference by placing string around the pipe and then flattening the length needed to do one full loop on to a tape measure or ruler. Always round up pipe lengths and remember to include the vertical parts. Do not worry about the connection sizes on individual appliances, the table is concerned with the pipe size into the kitchen area. Far East wok cookers normally need a minimum of 28mm gas pipe, but frequently 35 or 42 mm is required because of distance from the gas meter or other gas burning appliances on the line.

Pipe description Circumference (mm) Capacity (kW) at pipe length:

Note: each bend typically adds 0.5-1.0m to the straight length.

Figures are approximate and valid for UK natural gas only. Always consult an appropriate qualified Gas Safe engineer before proceeding.

Remember: capacity can be limited by the gas meter, you should complete that section too.

 

 

 

 

 

 

5m / 16′
10m / 32′ 15m / 49′
20m / 66′
30m / 98′
40m / 131′
22 mm OD copper 69 69 kW 41 kW 33 kW 30 kW 25 kW 22 kW
28mm OD copper 88 141 kW 95 kW 72 kW 63 kW 51 kW 43 kW
35mm OD copper 110 204 kW 151 kW 118 kW 108 kW 86 kW 75 kW
42 mm OD copper 132 344 kW 301 kW 247 kW 204 kW 161 kW 140 kW
54mm OD copper 170 753 kW 527 kW 430 kW 376 kW 301 kW 258 kW
2″ (50mm) ID steel 185 409 kW 301 kW 247 kW 204 kW 161 kW 140 kW
2 1/2″ (65mm) ID steel 229 1505 kW 1022 kW 860 kW 699 kW 591 kW 484 kW
3″ (80mm) ID steel 279 2581 kW 1828 kW 1452 kW 1237 kW 968 kW 914 kW

Upgrading or getting a new gas meter, pipe and supply

From the above you should have estimated the capacity of any existing meter and internal pipework, and what capacity is needed for your plans. If the meter is undersized, ask your gas supplier to swap it for bigger one but it’s very likely the supply pipe is undersized and needs replacing too (more on that shortly). The pipework after the meter probably needs to be bigger too, this pipe is your responsibility but Far East can supply and fit this for you, along with a gas interlock. Also consider your vent/extract system may need upgrading, as burning more gas will create more fumes. Alternatively, you can consider powering some of the catering equipment with electricity to reduce the gas requirements to match the existing capacity; note you cannot reduce required capacity by saying “I will never use all the burners at once” because safety testing is done with all gas appliances and burners at full rate.Gas Distribution Network Operator (DNO) map

Great Britain’s privatised gas industry has many layers. Twenty years ago you simply contacted British Gas for a bigger supply, but they no longer own the gas pipes. Today, you should enquire with your gas Distribution Network Operator (DNO) as they own and maintain the gas pipes in most streets and probably up to your gas meter . Do not contact National Grid Transco as they now only handle the very large pipes between towns and cities.

In addition to your DNO you can contact a GIRS UIP firms who is permitted to work on the DNO’s buried pipes but can pass ownership and maintenance to the DNO upon completion, such as Fulcrum, McNicholas, Morrison.

You can ask any gas supplier to quote a new connection or upgrade supply, however it’s likely they will simply take the DNO’s price and then add their own mark up . However, the gas supplier (who you pay your bill to) is responsible for your gas meter so you should still contact them about fitting the meter itself.

There are also independent gas transporters (IGTs) who connect from existing DNO pipes to your premises and could be cheaper, although they may recoup their investment through higher standing charges instead as they will own and maintain the pipe after completion.

There are also many commercial gas consultants who may be able to assist in getting new supply or upgrade and may know which UIP or IGT is likely cheapest for your requirements.

Disclaimer

Far East make no guarantees, provide no warranties and accept no liability for the general information provided, it is NOT to be used as a technical reference. Always consult an appropriately qualified Gas Safe Register engineer before proceeding with any works, in accordance with the Gas Safety (Installation and Use) Regulations (GSIUR) 1998 or other national regulations in force. The information is based on United Kingdom natural gas specification and practice, other countries use different mixtures of gas at different pressures that will invalidate the data provided here.