BS 8499:2009 pdf free download – Specification for domestic gas meter boxes and meter bracket.
4.4 Semi-concealed boxes
COMMENTARY ON 4.4
Subcla use 4.4 specifies the dimensional requirements for a semi-concealed meter box and incorporates the core dimensions of those box designs in use at the time of publication. However, in order to allow the fitting of the full range of meters covered by this Standard, it is recognized that existing designs might require modification when new tooling is introduced.
Therefore, when a manufacturer designs a new semi-concealed meter box, it should conform to both 4.4 and Figure 4. It is anticipated that the dimensions recommended in Figure 4 will become requirements when this Standard is revised.
4.4.1 The meter box shall have:
a) a method of restraining the meter from tilting by more than 30°, which can be achieved by either the design of the box or the use of a meter bracket that has been fitted to the box;
NOTE 1 A meter with dimensions of 136 mm deep (excluding the
depth of the meter index) x 188 mm wide x 218 mm high (including the
meter connections) is to be assumed when verifying this requirement.
NOTE 2 On existing semi-concealed meter installations the method of restraining the meter has been the responsibility of the meter asset manager where the meter box itself or a meter bracket has held the meter in its correct position.
b) a hole, with a diameter between 40 mm and 42 mm, reinforced to a thickness between 5 mm and 6 mm, positioned on the left hand side of the base of the box (when viewed from the front) to allow the service pipe to enter the box and be secured using the meter box adaptor. The centre of this hole shall be not less than 55 mm from the front internal surface the box and 70 mm from the left hand side internal surface of the box (box side/front/back);
c) a hole, with a diameter of not less than 40 mm, positioned near the top rear right side of the box to allow the installation pipework to exit the box;
d) fixing holes and fixings to secure the box to the wall;
e) a ground level line indicated on the external surface of the box;
4.4.2 The box shall incorporate, either by design or by the provision of purpose provided spacers, a gap of not less than 50 mm between the rear of the box and fixing area, e.g. brick wall.
NOTE When attaching a meter box extension, this dimension can be reduced by the thickness of the extension, i.e. 5 mm.
4.5 Universal boxes
4.5.1 The meter box shall meet the dimensional requirements of Figure 5, incorporating the following features:
a) a fitted meter bracket conforming to Annex B;
b) at least one thin-edged knockout to allow the service pipe to enter the box and be secured using the meter box adaptor. The area around this knockout shall be reinforced to a thickness of between 5 mm and 6 mm. Where a second knockout is provided, it shall be reinforced to the same thickness and positioned in accordance with Figure 5;
c) a hole to allow the installation pipework to exit the box;
d) fixing holes to secure the box to the wall;
e) a ground level line indicated on the external surface of the box.