BS 6644:2005 Specification for Installation of gas-fired hot water boilers of rated inputs between 70 kW (net) and 1.8 MW (net) (2nd and 3rd family gases)
This British Standard specifies requirements for the installation, including design, inspection and commissioning, of gas-fired hot water boilers of net rated heat inputs exceeding 70 kW but not exceeding a net heat input of 1.8 MW. Groups of boilers with individual net heat inputs of 70 kW or less, but with aggregate net heat inputs in excess of 70 kW, are also covered by this standard.
This standard is applicable to the installation of boilers that are designed to utilize normally distributed gases of Group H of the second family (e.g. natural gas), and gases of Group P (e.g. propane) and Group B (e.g. butane) of the third family. For the purposes of this installation standard, LPG/air mixtures are regarded as third family gases.
This standard is applicable to the installation of gas-fired hot water boilers within the scope of:
a) for boilers supplied as a complete assembly, BS EN 656 or BS 5978 (all parts);
b) for boilers supplied as a complete assembly and used in multiple boiler installations whose total net heat input exceeds 70 kW, BS EN 297, BS EN 483, or BS EN 677;
c) for boilers and burners delivered separately and assembled on site:
1) the boiler shell, BS EN 303-1, BS EN 12952, BS EN 12953 BS 779, BS 855, or BS 2790;
2) the burner, BS EN 676;
3) the assembly, BS EN 303-3 or BS 5987-1 and BS 5978-3.
NOTE 1 For the purposes of this standard, installation includes design, inspection and commissioning. It is recognised that each of these require different levels of competence (see 4.1.2). Where all of these tasks are performed by same person, that person has to have the necessary levels of competence for each task.
NOTE 2 Although this standard does not contain any requirements for industrial processes, the general principles can be applied.
NOTE 3 The general principles of this standard with respect to hot water circuits can be used for boilers exceeding 1.8 MW net heat input (2 MW gross heat input). For installations exceeding 1.8 MW net heat input, see IGE/UP/10 [15].
NOTE 4 The ratio of gross to net heat input is approximately 1.11:1 for Group H (natural gas), 1.09:1 for Group P (propane) and 1.08:1 for group B (butane).
It is also applicable to installations that have been converted from burning other fuels to gas-firing. This standard is not applicable to:
a) the installation of any heating or hot water supply system associated with the boiler installation,
b) the installation of gas cushion systems (non diaphragm expansion vessels) intended to pressurize the hot water circuit, or
c) installations in hazardous areas, as defined in The Dangerous Substances and Explosive Atmospheres Regulations [14].
BS 6644:2005 history
0000 BS 6644:2011(2013)
2011BS 6644:2011 Specification for the installation and maintenance of gas-fired hot water boilers of rated inputs between 70 kW (net) and 1.8 MW (net) (2nd and 3rd family gases)
2005BS 6644:2005+A1:2008 Specification for Installation of gas-fired hot water boilers of rated inputs between 70kW (net) and 1.8 MW (net) (2nd and 3rd family gases
2005BS 6644:2005 Specification for Installation of gas-fired hot water boilers of rated inputs between 70 kW (net) and 1.8 MW (net) (2nd and 3rd family gases)