Water Softener

The pressure is not the main thing. Instead, you need to focus on whatever minerals or other impurities may be in the feed water. In the U.S., local water treatment specialists are often the best to consult, but I don't know what you would have available.

For sure. As is a proper management regime such as pH correction, blow down arrangements, and periodic washout, Murphy.

I think that the question you are asking is; "where can I get a high pressure water softener to feed an 8 bar boiler?"

You may have to contact someone who manufactures valves and tanks. Most domestic water softeners recommend not exceeding 100 psi or 7 bar pressure. The maximum operating pressure for many fiberglass tanks is just greater than 8 bar but valves are often less. Find a manufacturer who uses steel tanks or steel reinforced tanks with higher than 125 psi or 8.5 bar. Contact a valve manufacturer like Fleckenstein or Autotrol (Pentair). Also be aware that there will be a pressure drop across the softener and that should considered in your design.

From Lenntech specifications.

Water absorbs more heat for a given temperature rise than any other common inorganic substance. It expands 1600 times as it evaporates to form steam at atmospheric pressure. The steam is capable of carrying large quantities of heat. These unique properties of water make it an ideal raw material for heating and power generating processes.
All natural waters contain varying amounts of dissolved and suspended matter and dissolved gases the amount of minerals dissolved in water varies from 30 g/l in sea water to anything from 0.005 to 1500 mg/l in fresh water supplies. Since water impurities cause boiler problems, careful consideration must be given to the quality of the water used for generating steam.
The composition of boiler feed water must be such that the impurities in it can be concentrated a reasonable number of times inside the boiler, without exceeding the tolerance limits of the particular boiler design. If the feed water does not meet these requirements it must be pretreated to remove impurities. The impurities need not be completely removed in all cases, however, since chemical treatment inside the boiler can effectively and economically counteract them.

Feed-water purity is a matter both of quantity of impurities and nature of impurities: some impurities such as hardness, iron and silica are of more concern, for example, than sodium salts. The purity requirements for any feed-water depend on how much feed water is used as well as what the particular boiler design (pressure, heat transfer rate, etc.) can tolerate. Feed-water purity requirements therefore can vary widely. A low-pressure fire-tube boiler can usually tolerate high feed-water hardness with proper treatment while virtually all impurities must be removed from water used in some modern, high-pressure boilers.
Only relatively wide ranges can be given as to maximum levels of alkalis, salt, silica, phosphates etc, in relation to working pressure. The actual maximum levels must be obtained fro the boiler manufacturer, who will base them on the characteristics of the boiler in question.

The following tables are extracts of recommended levels from APAVE (Association of electrical and steam unit owners), up to pressures of 100 bar for medium steaming rates and for volumes of water in the chambers sufficient to properly control the blow down rates, and from ABMA (American Boiler Manufacturers Association) in its standard guarantee of steam purity.

Find information about the main problems occurring in boilers: scaling, foaming and priming, and corrosion.
Check also our general web page about boiler feed water.
Click here for more information about boiler water treatment, in particular through deaeration (deaerating heaters or membrane contractors)

Read more: http://www.lenntech.com/applications/process/boiler/boiler-feedwater-characteristics.htm#ixzz3JitKRq4p

WP

Water softeners are used to treat the raw boiler FEED Water. The make up water used to replace any lost or used up steam. A water softener is not used to treat the recirculating condensate or steam.

Chemical compounds are added to the boiler to do various things to the steam and water/condensate. What is contained in them is determined by the conditions of the water in the system and sufficient blow downs. The major components are oxygen scavengers, coagulants, phosphates, and chelants usually in a sodium hydroxide solution. Each has its own purpose and the mix must be chosen to treat the unique condition of the condensate water. Unless you have the capabilities to test in-house it is best to use your supplier to test the condensate water.

In addition, sufficient blow downs of the boiler must be done to remove the dirt and solid by-products of the chemical treatments.

No, there is no water softener that will operate at 8 bar of pressure for a steam boiler. The softener is for feed/make-up water. Chemical treatment is used for treatment of the condensate and steam.

Good Luck, Old Salt