With our comprehensive range of GEMÜ products, we meet the demands of applications such as sea water desalination and water treatment of WFI (water for injection).

The pressure range used for membrane filtration or ultra-filtration is between 0.2 and 6 bar. For nano-filtration or reverse osmosis, the operating pressure can be up to 80 bar depending on the salt concentration. The size of membrane systems varies from small systems, for example a water supply for few consumers, right up to large industrial parks for the treatment of industrial water or larger water supplies for thousands of people.

Water is precious – and we supply the technology to handle it sustainably.

Subdivision between the major areas of application: Process water, ultra pure water and industrial water treatment for reusing water.

The purification of process water and waste water is a high priority in production processes, since almost nothing is made without water. Reusing water plays an ever-more important role in the current climate and requires various valves and components to ensure the optimal treatment of the water for reuse.

For boiler feed water, it is important to have a lower level of dissolved salts such as lime, NaCl, etc. To produce boiler feed water, the water is first pre-filtered. Depending on the source, this may require a simple bag filter or an elaborate multi-layer filter. Then, reverse osmosis removes the majority of the dissolved salts. For fresh water the pressure for reverse osmosis is usually < 20 bar. Ball valves and butterfly valves are frequently used. Stainless-steel globe valves can be used for pressure regulation. 

The subsequent ion exchanger is usually designed as a mixed-bed exchanger. However, it is also possible to construct cation exchangers and anion exchangers separately. The remaining dissolved salts are absorbed into the ion exchanger and regularly regenerated.  Diluted acids such as hydrochloric acid and sulphuric acid are used for regeneration in cation exchangers. Anion exchangers usually use sodium hydroxide for regeneration. 

GEMÜ products: 

Ion exchanger = diaphragm valves or butterfly valves, EPDM or PTFE gasket, PVC body, PP or coatings made from hard rubber, Halar or PFA are also possible. 

Modern sea water desalination plants work with multiple process steps. The first step is sieving out large particles. The second filtration stage also removes fine particulate and organic matter such as algae. The actual desalination takes place in high-pressure reverse osmosis systems. The ultra-filtration stage is usually carried out at a low pressure under 6 bar. One special feature is the frequent backwashing processes to avoid blockages in the diaphragms. The UF diaphragms are also regularly cleaned using diluted chemicals. Acids such as citric acid, hydrochloric acid or sulphuric acid eliminate any inorganic contaminants. Organic impurities are eliminated using alkalis. This frequently takes place in combination with disinfection using a sodium hypochloride solution.

GEMÜ products:

Ultra-filtration = butterfly valves with discs coated with Rilsan or Halar, gasket is usually EPDM

Chemical dosing = solenoid valves or diaphragm valves