BS EN 15848:2010 pdf download.Water conditioning equipment inside buildings – Adjustable chemical dosing systems – Requirements for performance, safety and testing.
4 Design requirements
4.1 General
The dosing system shall function to maintain a specific concentration of the chemical in the treated water.
4.2 Dosing system components
A dosing system comprises the following elements:
a) storage tank or chemical container which contains the chemical as a liquid that will be dosed into the water pipe;
b) suction device which comprises a suction hose and a foot valve;
c) low level detection avoiding the pump to work when storage is empty;
d) dosing pump that pumps the chemical as a liquid from the storage tank or container and doses it into the main water flow;
e) overpressure valve as safety apparatus to avoid overpressure in the injection device:
f) injection device which comprises the hose between the pump and the mains, the injection valve and the backflow preventer;
g) water meter in the main water flow which transmits a control signal to the dosing pump.
4.3 Materials of construction
Parts in contact with drinking water shall comply with national regulations.
The temperature resistance of the injection system shall be specified.
4.4 Venting
The dosing system shall be designed so that accumulation of air or other gases is prevented.
Compliance with this requirement shall be checked by examination of the detailed technical design documents
supplied with the system.
4.5 Radio interference and electrical safety
The dosing system shall conform to EN 12100-1, EN 12100-2, EN 55011, EN 60204-1, EN 60335-1 and EN 60335-241, following the provisions of Directive 891336/EEC [2] and Directive 73123/EEC 131.
4.6 Accessibility
All parts which have to be accessed for replenishing of the dosing agent and for operat,or, or servicing shall be
easily accessible,
4.7 Nominal size
If the dosing pump is controlled by signals from a water meter. the nominal size of its connection shall correspond to the flow rates given in Table 1. The inlet connection size of the water meter may be one size larger or smaller than the nominal size. For flange connections the inlet flange shall conform to the nominal size.
4.8 Manual mode
The dosing system shall have an indication when a manual mode is activated, for example, for maintenance.
5 Performance requirements
5.1 Chemicals
The documentation shall define which chemicals are compatible with the dosing system and at which maximum concentration.
All the dosed chemicals shall conform to the relevant European Standards.
5.2 Dosing system components
5.2.1 Storage tank or chemical container
Materials selected for the manufacture of the dosing tank shall protect the contents against contamination or degradation by corrosion, light, dust, particles or any external pollutant. The design of the connection between the dosing tank and the dosing pump shall exclude any
— accidental contamination of the contents during either normal operation or chemical replacement:
leakage of the chemical to the external environment of the system.
The normal working capacity of the chemical storage tank or container shall not exceed three months based
on the minimum dosing rate for the designated chemical.
5.2.2 Suction device
The suction device shall have a backflow preventer.
5.2.3 Low level detection
The low level detection shall as a minimum stop the pump when the storage is empty.
5.2.4 DosIng pump
The manufacturer shall specify the dosing pump operating characteristics (maximum volume per stroke at maximum and medium specified operating pressure), all of which shall be tested separately. Measurements shall be carried out in accordance with to 6.2. Parameters are given in Table 2.BS EN 15848 pdf free download.