Silver Ion Sterilizer


Separator Spares & Equipment, LLC is an Authorized JOWA Distributor and Service Center.

JOWA AG-S Silver Ion Sterilizer for freshwater disinfection

Treatment of drinking water with silver is a very old method and is used in many parts of the world. This method goes back to the ancient Egyptians. Dosing water with Silver ions kills off bacteria, germs, and algae, and controls their regrowth within the water storage and distribution system. The process by which the bacteria and algae are killed is called oligodynamical sterilization. The silver ions are released by electrolysis from two silver plates within a special electrode unit when a controlled current (DC) is driven through them.

Silver ions do not affect the physical and chemical properties of the water and do not change the taste, smell, or color. The amount of silver ions in the treated water is well below the maximum amounts stated in the directives issued by the World Health Organization (WHO).

The JOWA Ag-S Silver Ion Sterilizer is well-known in the shipping industry with thousands of installations since its introduction in 1970. Due to its simple design and high quality, many of the early units are still in operation and only need periodic replacement of the electrode. Very little maintenance is required as high quality materials are used.

The electrode chamber as well as the common base plate are made of polished stainless steel and need no maintenance. The JOWA Ag-S Silver Ion Sterilizer uses 99.99% pure silver in both of the electrodes and also shifts the current direction once every ten minutes so there is no oxidation or growth on the surface of the electrodes, and so no regular cleaning is required.

The JOWA Ag-S Silver Ion Sterilizer comes as one unit ready to be fitted onto the bulkhead. It consists of an electronic cabinet, an electrode chamber with two shut-off valves, a flow setting valve, and a flow switch. All these parts are mounted on a common electro- polished stainless steel base plate.

An optional flow meter can automate the dosage of silver based on the volume of water generated or bunkered.



  • Treatment capacity max. 15 m³/h
  • Operates on 100 to 240VAC 50/60Hz
  • Automatically adjusts for water conductivity
  • Compact design
  • Continuously monitors Electrode condition
  • Inputs for optional flowmeters
  • Optional Remote Panel (Slave or Master)
  • Remote Start interconnect for the watermaker


  • Chemical Free
  • Alternative to chlorine
  • Long-lasting residual treatment
  • No change in taste, smell, or color of water
  • No change to physical or chemical properties of water
  • Easy to change electrodes
How does JOWA Silver Ion Sterilizer work?

There are many ways to treat water to make it suitable for drinking or to reduce biological growth within a water system. The JOWA Ag-S Silver Ion Sterilizer is a long-term system used for storage tanks where the water is kept for a period of time. After a 4 hour contact time, the silver ions kill bacteria and prevent re-growth.

Silver-Ion-Water-Treatment-SystemThe JOWA Ag-S is a well-known product in the shipping world. Since its introduction in 1970 several thousand ships have installed it. The process by which the bacteria and algae are killed is called oligodynamical sterilization. The silver ions are released by electrolysis from two silver plates within a special electrode unit when a controlled current (DC) is driven through them.

The JOWA Ag-S electrode unit consists of two high purity (99.99%) silver plates. The water passes through the center of the electrode and between the two silver plates. The released silver ions, following the current direction between the plates, are forced by the water to flow out of the electrode chamber and into the piping system. By changing the current direction once every ten minutes the silver ions will be released evenly from both plates over a period of time. The periodic change of current also keeps the plates clean, eliminating otherwise necessary regular cleaning.

Treating drinking water using silver is a very old method and has been used frequently in many parts of the world since ancient times. Before the introduction of penicillin, silver was used in many medical products and has proven to be effective. Today silver is used in thousands of products to prevent biological growth.

JOWA-Silver-Ion-SterilizerThe JOWA Ag-S Silver Ion Sterilizer can have the concentration of silver ions set for any value between 0.025 mg/l (25 ppb) and 0.10 mg/l (100 ppb). The most common settings are either 0.04 mg/l (40 ppb) or 0.10 mg/l (100 ppb) silver. This setting is user-controlled and depends on the ruling administration.

The electronics automatically adjust the silver output dependent upon the volume of water selected, the flow rate of the watermaker, or automatically when an optional flow meter is used. An alarm is activated when the electrode is consumed or any other system problem is detected. An optional audible/visible alarm can also be fitted in the main control room to indicate any malfunction of the unit (e.g. low flow of water, electrode consumed).

The user should measure the concentration of the silver ions annually. Samples should be taken from the outlet of the storage tank(s) and at the extremity of the system. Care must be exercised over the collection and storage of the samples, and it is strongly recommended that the advice of a competent laboratory is sought and followed. Normally such a laboratory will supply full instruction and sterilized bottles.

Required spare parts for JOWA Ag-S Silver Ion Water Treatment System


Part Numbers Description
30002-24209 Silver electrode*
32152-00016 Flow regulator, DN15 2-8 l/min
33026-00002 Connection plug, female
19001-15156  Ball Valve, DN15 female/female
9801010 Flow switch, DN10, G⅜” 2 l/min
9801007 Solenoid Valve, G½”, 24VDC
9400105 Ball Valve, DN10 male/male
2165804 Main Board, PCB Assembly
2165821 Display Board, PCB Assembly
2165801 Membrane Switch
9170302 Fuse, Cartridge, 250V, 1.5A Slow Blow
Optional Parts
92000-00023 Flowmeter, G1” union connection, nominal 6 m3/h rate,
10 L/Pulse

*Silver electrode for the JOWA Silver Ion Sterilizer is the only recommended spare part for two (2) years of operation

Disinfect Drinking Water with Silver Ion Water Treatment System

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