With water presence sensor
Constant dosing, activated automatically when water flows in the discharge pipe.
Components and diagram →
Swimming pool systems
Dechlorination of discharges
Filter backwash water and pool drain-down water must be dechlorinated before discharge: a dosing pump injects the dechlorinating agent into the pipe, with constant dosing or dosing proportional to the volume discharged.
- Backwash and drain-down
- Constant or volumetric dosing
- Limits of D.Lgs. 152/2006
0.2mg/lFree active chlorine in surface water
0.3mg/lFree active chlorine in sewers
2Systems: constant or volumetric
Why
Two systems: constant or volumetric
Filter backwash water and drain-down water must be dechlorinated before discharge: Italian Legislative Decree 152/2006 (D.Lgs. 152/2006, Annex 5 to Part Three) sets a limit for free active chlorine of 0.2 mg/l in surface water and on soil and of 0.3 mg/l in sewers, unless stricter regional limits apply. A dosing pump injects the dechlorinating agent (for example sodium metabisulphite or hydrogen peroxide) into the discharge pipe.
With pulse-output water meter
Dosing proportional to the volume of water discharged, measured by the water meter.
Components and diagram →Types of water, discharge limits and treatments: swimming pool water discharges.
With sensor
With water presence sensor
The capacitive sensor detects water in the pipe during the discharge phases and activates the pump, which doses a constant quantity of dechlorinating agent (0 – 800 or 0 – 8,000 g/h). The quantity is determined on the basis of the total chlorine in the pool, the flow rate of the recirculation pump and the quantity of product required to reduce the chlorine by 1 mg/l, stated on the label.
Water presence sensor
Capacitive, with no contact with the water: it is installed on the outside of the pipe with a clamp saddle and a 3/4" fitting. Sensitivity adjustable by trimmer, signal LED, IP 67 protection rating.
Dosing pump
Activated by the sensor, it doses a constant quantity of dechlorinating agent set with the knob, from 0 to 800 or from 0 to 8,000 g/h; product level probe.
Dosing pumps → Tank with safety bund
In PE, with safety bund against spills and suction lance with level probe.
Tanks →
With water meter
With pulse-output water meter
Dosing is proportional to the volume measured by the water meter on the discharge. The settings are the pulses per litre (turbine meters) or the litres per pulse (Woltmann meters), the total chlorine, the concentration of product to be dosed and the strength of the product.
Pulse-output water meter
Turbine or Woltmann type, 1” 1/2 or 2”, on the discharge pipe: it sends the pump a pulse for every set volume of water.
Water meters → VMS MF dosing pump
Multifunction pump in volumetric proportional control: it doses the dechlorinating agent in ppm according to the pulses from the water meter. Versions of 3 bar / 10 l/h or 2 bar / 15 l/h; product level probe included.
VMS MF → Tank with safety bund
In PE, with safety bund against spills and suction lance with level probe.
Tanks →
Applications
Where it is used
In public, collective-use and private swimming pools: the discharge of backwash and drain-down water must comply with the legal limits.
Public swimming pools and pools for collective use
Type 1, 2 and 3 pools according to UNI 10637:2024 (Italian standard): automatic measurement and control of pH and free chlorine.
Public swimming pools → Private swimming pools
Residential pools, where free chlorine, Redox, hydrogen peroxide and salt are all options.
Private swimming pools →
Installations
Installation examples
Systems are supplied pre-assembled and tested, in the form best suited to the plant room: on a panel, in a cabinet or on a skid (with cover, in a box or on a frame), also tailor-made. Some examples.
On a panel
Controller, pumps, probe holder and accessories mounted and wired on a wall panel.
In a cabinet
System panel and chemical tanks housed in a single cabinet.
Wall cabinet
Pipework, pumps and electrical panel in a wall cabinet with door.
Skid with cover
Skid with raised stainless steel frame and protective PMMA cover.
Skid in a box
Skid enclosed in a box with door, with the chemical tanks at the base.
Skid on a frame
Skid on a frame with doors, pre-assembled and ready for connection.
On the tank
Dosing pump mounted directly on the tank: the most compact solution.
In the plant room
Wall installation in the plant room, with the chemical tanks on the floor.
Pumps, controllers or components supplied by the customer can also be fitted, with custom dimensions, back panel and electrical panel. Dosing stations and skids →
Which one to choose
From the simplest to the most complete solution
For chlorine and other disinfectants the basic solution is the dosing station; to dose according to the concentration actually present in the water, measuring controllers are used.
Dosing station
The simplest solution: the pump doses at a constant rate or in proportion to the volume of water measured by the pulse-output water meter.
Details →
LDsRh
Dosing based on the Redox potential of the water: an economical solution, based on an indirect measurement.
Details →
LDsCL
The amperometric cell directly measures the disinfectant concentration in mg/l, ensuring maximum dosing accuracy.
Details →
LD Dual Parameter
Simultaneous management of two parameters, for example pH and chlorine, with a single controller.
Details → Centurio PRO
Management of up to 10 parameters and of all the pumps in the installation, with touch screen and remote control as standard.
Details →Technical consultancy
Tell us the flow rate of the recirculation pump, the total chlorine in the pool and the type of discharge: we will size the pump and the activation system.