Ulvac C30HVRT - Table 2-3 Table

Section 2. Considerations before Installation
2.3.1 Checking chemicals and quality of water
Table 2-3 indicates recommended quality of water. Ensure that cooling water meets the
requirements in the table. If the quality of water is not in allowable ranges, water quality
improvement may be needed.
Table 2-3 Recommended cooling water for compressor
Item Unit Allowable Range
pH (25℃)
※１
pH 6.5 - 8.0
Conductivity (25℃)
※１
mS/m < 30
Chloride ion, CI
-
※１
mg / L < 50
Sulfate ion, SO
4
2-
※１
mg SO
4
2-
/ L < 50
Acid consumption (pH4.8)
※１
mgCaCO
3
/ L < 50
Total hardness
※１
mgCaCO
3
/ L < 50
Total carbonic acid
※１
mg/ L < 10
Calcium carbonate mg/ L < 75
※１ The values of the items are based on the water quality management standards of Japan Refrigeration and
Air Conditioning Industry Association.
Note1: Table 2-3 is based on the water quality management standards of Japan Refrigeration and Air
Conditioning Industry Association. Refer to local standards of water quality management where the
compressor is installed outside Japan. It is necessary to check chemicals and water quality to avoid
corrosion, clogging, and other faults caused by low quality of water and/or chemicals.
Note2: Ground water may contain a great quantity of carbonate acid which facilitates corrosion. Ensure to
perform carbonate check as soon as water is taken from ground without exposing water to atmosphere.
Otherwise the result may be false.
2.3.2 Determining pressure, temperature and flow rate of cooling water
Refer to Table 1-3 in Section 1for typical cooling water requirements.
The pressure of cooling water for supply lines must be 0.7MPaG or less.
Figures 2-3 shows the relation of water flow rate, water temperature, and water pressure
loss. Use the graph in Figure 2-3 to determine the flow rate of cooling water.
For example, from the graphs in Figure 2-3, the allowable range of the flow rate for
C30HVRT is from 9 to 15L/min at water temperature of 30℃. Also you can see the water
pressure drop between the cooling water inlet and outlet is 0.06MPa at a flow rate of
9L/min.
Determine the values for water flow late and pressure loss so that the compressor can be
run with an enough margin to the water temperature change throughout the year.
If the cooling water is cooler than 10°C, stop the water flow when the compressor is
suspended. If the cooling water of below 10°C is kept flowing, it may raise viscosity of
lubricant oil and the compressor may fail to startup when turned on.
CAUTION
2-4
ULVAC CRYOGENICS INCORPORATED