Ulvac RFP-N - Cooling Water Quality Standards

RF POWER SUPPLY and MATCHINGBOX
2. Overview
6
2-4. Cooling water quality standard
Table 2-2 Cooling water quality standard*
Item
Substance
Water quality standard
Water temperature
25°C or lower (no condensation)
Specific resistance
5 kΩ∙cm or higher
pH
7.0 to 8.0
Chlorine ions
Cl
－
100 ppm or lower
Acid consumption (pH 4.8)
CaCO
3
100 ppm or lower
Total hardness
CaCO
３
50 ppm or lower
Calcium hardness
CaCO
3
50 ppm or lower
Ionic silica
SiO
2
20 ppm or lower
Iron
Fe
0.5 ppm or lower
Copper
Cu
0.3 ppm or lower
Sulfide ions
S
2-
Not detected (ppm)
Ammonium ions
NH
4
+
Not detected (ppm)
Residual chlorine
Cl
0.3 ppm or lower
Free carbonic acid
CO
2
4 ppm or lower
Stability index (Ryznar index)
-----
6.0 to 7.0
Mattsson ratio
HCO
3
-
/SO
4
2-
1 or higher (SO
4
2-
/HCO
3
-
< 1)
Oxygen amount (DO)
-----
0.1 ppm or lower
Aluminum
Al
0.2 ppm or lower
Manganese
Mn
0.1 ppm or lower
Nitrate ions
NO
3
-
100 ppm or lower
Sodium ions
Na
+
20 ppm or lower
Phosphate
PO
4
3
−
2 ppm or lower
Ammonia
NH
3
0.5 ppm or lower
Manganese ions
Mn
+
10 ppm or lower
Hydrogen sulfide
H
2
S
0.05 ppm or lower
Dissolved solids
-----
50 ppm or lower
Turbidity
-----
2 degrees or lower
Mixture
Must pass through a 50 mesh filter, not form deposits or scale in a water temperature of 60°C.
Total amount of solid material is 250 mg/l or less
* Water quality test is compliant to JIS K0101 or a test conforming to that standard.
* Using cooling water that does not meet these conditions may shorten the service life of the RF Generator or cause malfunctions.
* Avoid using deionized water.
(If deionized water is exposed to the atmosphere, it absorbs atmospheric carbon dioxide which becomes free carbonic acid in the
water and lowers its pH. If the water temperature and the flow rate are high when the pH is low, erosion
*1
and corrosion
*2
may
occur.)
*1: Erosion
A phenomenon where solid particles in the fluid collide with a material. The material is damaged or material is removed from the
surface of the material that was hit.
*2: Corrosion
Rust (green rust) forms due to free carbonic acid that occurs from water and carbon dioxide. This phenomenon degrades the
system's mechanical properties by the formation of rust
* Caution
Always ensure that the water temperature and water volume follow the specifications.