|
|
|
|
COLLISION WITH GLAZING
(P2.2) The requirements of P2.2 will be met where glazing is in accordance with BS 6262: Part 4: 1994.
CLEANING OF WINDOWS AND ROOFLIGHTS
(P2.3) The requirements of P2.3 will be met where external and internal glazed surfaces can be cleaned safely from -
a. inside the building in accordance with the requirements of Clauses 10.2, 10.3 and 10.4 of BS 8213: Part 1: 1991; or
b. a loadbearing surface, eg balcony, catwalk, roof surface etc to which safe access can be obtained; and
i. which has a protective barrier not less than 1.1 m high, where any edge of the surface or access is likely to be dangerous; and
ii. where no part of the glazing is more than 4 m above the surface.
c. a window access system mounted on the building in accordance with Clause 9 of BS 8213: Part 1: 1991.
(P2.4) The requirements of P2.4b.ii. will be met by -
a. a loadbearing surface, eg balcony, catwalk, roof surface etc to which safe access can be obtained; and
i. the access is suitable for carrying a portable ladder; and
ii. which has a protective barrier not less than 1.1 m high, where any edge of the surface or access is likely to be dangerous.
EMERGENCY STOPPING OF ESCALATORS AND PASSENGER CONVEYORS
(P2.5) The requirements of P2.5 will be met where the location of the devices and the stopping of the equipment complies with the requirements of BS EN 115: 1995.
(P2.8) The requirements for access will be met by stairs, ladders and walkways complying with BS 5395: Part 3: 1985 and the requirements for the visible warning will be met by sign A2.4 of BS 5378: Part 3:1982.
UNVENTED HOT WATER STORAGE SYSTEM
(P3.1) The requirements of P3.1 will be met where the storage vessel of an unvented hot water storage system meets the following requirements.
1 Hot water storage system having a storage vessel of not more than 500 litres capacity having a power input not more than 45 kW.
In this specification -
UNIT means a vessel for heating water or storing hot water, factory fitted with the safety devices described in 1b below and incorporating other operating devices to stop primary flow, prevent backflow, control working pressure, relieve excess pressure and accommodate expansion all fitted on the unit by the manufacturer; and
PACKAGE means a vessel for heating water or storing hot water, factory fitted with the safety devices described in 1b below and supplied by the manufacturer with a kit containing other operating devices to stop primary flow, prevent backflow, control working pressure, relieve excess pressure and accommodate expansion, to be fitted to the system by the installer.
a. An unvented hot water storage system must be in the form of a proprietary unit or package which is:
i. the subject of a BBA Certificate; or
ii. Kitemarked to BS 7206: 1990.
SAFETY DEVICES
b. A unit or package must have, subject to the requirements of 1c below, a minimum of 2 temperature activated devices operating in sequence comprising —
i. a non self-resetting thermal cut-out; and
ii. a temperature relief valve.
The 2 devices are additional to any thermostatic control which is fitted to maintain the temperature of the stored water.
c. In indirectly heated units and packages the non self-resetting thermal cut-out should be wired up to a motorised valve, or some other device specified in the BBA Certificate or British Standard, to shut off the flow to the primary heater. If the unit incorporates a boiler the thermal cut-out may be on the boiler.
d. Where an indirect unit or package has any alternative direct method of water heating fitted a non self-resetting thermal cut-out device will also be needed on the direct source(s).
e. In both directly and indirectly heated units and packages, the temperature relief valve referred to in 1b above should be located directly on the storage vessel. The valve should be sized to give a discharge rating at least equal to the power input to the water. The valve should not be disconnected other than for replacement or relocated in any other position nor the connecting boss used to connect any other device or fitting. Each valve should discharge via a short length of metal pipe of a size not less than the nominal outlet size of the temperature relief valve either directly or by way of a manifold sized to accept the total discharge from the discharge pipes connected to it, through an air break over a tundish located vertically as near as possible to the valve.
f. The discharge pipe from the tundish should be of suitable metal and be at least one pipe size larger than the outlet pipe on the safety device. The pipe should be laid to a continuous fall and be no longer than the equivalent in hydraulic resistance of a pipe 9 m long unless the bore is increased. The pipe should terminate in a visible but safe place such as a gully, where there is no risk of contact with the discharge by persons.
2 A hot water storage system having a storage vessel of over 500 litres capacity or having a power input more than 45 kW.
REQUIREMENTS
a. These systems will generally be for projects specified to unique designs.
SAFETY DEVICES
b. An unvented hot water storage system with a storage vessel of more than 500 litres capacity and a power input not more than 45 kW should have safety devices in accordance with the recommendations of Section 2 Clause 2.4 in BS 6700: 1997.
c. Any unvented hot water storage vessel with a power input of more than 45 kW should have the appropriate number of temperature relief valves either to BS 6283: Part 2: 1991 or Part 3: 1991 to give a combined discharge rating at least equal to the power input or equally suitable temperature relief valves marked with the set temperature in °C, and the discharge rating marked in kW, measured in accordance with Appendix F of BS 6283: Part 2: 1991 or Appendix G of BS 6283: Part 3: 1991, at least equal to the power input. The valves should be factory fitted to the storage vessel and the sensing element located as described in 1e.
INSTALLATION
d. Non self-resetting thermal cut-outs appropriate to the heat source should be incorporated in the system and installed as described in 1d.
e. Discharge pipes to convey any discharges from safety devices should be installed as described
in 1f.
|
|
|