SNiP 2.04.02-84

СНиП на английском языке SNiP 2.04.02-84

6.145. The introduction of chlorine-containing reagents for water disinfection shall be performed
in pipes before purified water tanks.
The need to purify ground water shall be determined by agencies of the sanitary-epidemiological service.
Note: When justified, it is permissible to use special contact tanks to support contact of chlorine-containing reagents
with water.
6.146. The dose of active chlorine required to disinfect water shall be established on the basis of
process testing data. If such data are not available, in preliminary calculations for surface water after
filtration a figure of 2-3 mg/L may be used, for water from underground sources 0.7-1 mg/L.
The concentrations of residual free and bonded chlorine shall be taken in accordance with GOST
2874-82.
Note: When water to be used for drinking and domestic purposes is stored in tanks for the period when one of them
is disconnected for washing and repair in cases when the time of contact of the water with chlorine is not provided,
twice the normal dose of chlorine shall be administered. The increased dose of chlorine may be provided by the use
of reserve chlorinators.
6.147. The chlorine section shall support reception, storage and evaporation of liquid chlorine,
measurement of gaseous chlorine to produce chlorine water.
Chlorine water shall be fed separately to each input point.
The chlorine section shall be located in separately standing chlorine facilities, which shall also
contain the service chlorine storage facility, evaporator and chlorine dosing facilities. The service
chlorine storage facility may be located in separate buildings or may be adjacent to the chlorine dosing
and supplementary chlorine section rooms (compressor and ventilator rooms, etc.); it shall be separated
from other rooms by a continuous wall having no openings.
6.148. Service chlorine storage facilities shall be planned in accordance with Paragraphs 6.211
and 6.212. When justified, a separate chlorine storage facility may not be provided; in this case, one
liquid chlorine storage cylinder with a net mass of not over 70 kg may be present in the chlorine dosing
area.
6.149. Chlorine evaporators shall be placed in the chlorine storage facility or chlorine dosing
area. Chlorine shall be evaporated in special evaporators or cylinders (in which the chlorine is delivered).
The temperature of the water fed into the evaporator shall be within the limits of 10-30°C, and
the decrease in water temperature in the evaporator shall be not over 5°C.
The evaporator shall be equipped with devices to monitor the water temperature and the pressure
of the chlorine and water. When gaseous chlorine is fed outside the building, devices shall be installed
after the evaporator to purify the gas, as well as a valve to maintain a vacuum such that the chlorine will
not condense at the lowest ambient air temperature.
The length of the gaseous chlorine pipe shall not exceed 1 km.
6.150. Chlorine dosing facilities without evaporators, located in facilities connected to other
water supply buildings or supplementary chlorine section rooms shall be separated from other rooms by a
continuous wall having no openings and equipped with two external exits, one of which has a double
door. All doors shall open outward. The floor of the chlorine dosing section, if located above other
rooms, shall be impervious to gas. Chlorine dosing sections may not be located in rooms with floors
below ground level.
6.151. Automatic vacuum chlorinators shall be used for chlorine dosing purposes.
The calculated flow rates and heads of water fed to the chlorinator and the pressure of the
chlorine water downstream from the chlorinator shall be determined based on the characteristics of the
chlorinator, as well as its location relative to the point where the chlorine is added.
It is permissible to use a manually controlled chlorinator in which the chlorine feed is monitored
by weight.