Description of BS 6891:2015+A1:2019 2019

This British Standard specifies the design, installation, commissioning and maintenance of gas installation pipework carrying 2nd and 3rd family gas of up to 35 mm (R 1¼) on premises, including residential park homes (2nd and 3rd family gas) and caravan holiday homes (2nd family gas) (see Table 1 and examples in Figure 1 to Figure 3; see also Figure 4).

NOTE 1 The principles of the standard can also be applied to the design, installation, commissioning and maintenance of gas installation pipework carrying 1st family gas.

NOTE 2 Annex A gives a method for calculating pipe sizes. Annex B discusses the sulfidation of natural gas installations, while Annex C summarizes the conclusions of a report on gas in intermediate floors. Guidance on determining whether an area can be deemed a “protected area” is given in Annex D. Requirements for LPG final stage regulator and safety devices are specified in Annex E. Annex F discusses the need for gas pipework design and installation for commercial installations to satisfy regulatory requirements regarding explosive atmospheres.

This British Standard is not applicable to:

1. service pipework and distribution systems;

2. pipework contained within an appliance;

3. bulk storage vessels;

4. LPG pipework installed in leisure accommodation vehicles and for accommodation purposes in vehicles in accordance with BS EN 1949;

5. boats, yachts and other vessels;

6. gas pipework supplying or within appliances having their own gas supply, such as mobile heaters; or

7. gas pipework supplying or within catering establishments covered by BS 6173.

Table 1 Pipework covered by BS 6891

^A) Dependent upon material type.

^B) 1 bar = 105 N/m² = 100 kPa.

NOTE Unless stated otherwise:

a) the diameter for pliable corrugated (stainless-steel) tubing refers to the inside diameter; and

b) the diameter for carbon, stainless-steel tubing, copper and polyethylene (PE) refers to the outside diameter.

Figure 1 2nd family gas installation with an internal meter

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Figure 2 3rd family gas installation with cylinders

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Figure 3 3rd family gas installation with bulk storage vessels

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Figure 4 Selection of applicable standard(s) for gas installations

* Industrial and commercial

NOTE For commercial premises less than 35 mm, IGEM/UP/2 [12] may also be utilized.

About BSI

BSI Group, also known as the British Standards Institution is the national standards body of the United Kingdom. BSI produces technical standards on a wide range of products and services and also supplies certification and standards-related services to businesses.