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Water quality standards, Iom manual hbh series heat controller, inc, Table 3: water quality standards – Comfort-Aire HBH Series 6-10 Tons User Manual

Page 18: Scaling potential - primary measurement, Index limits for probable scaling situations, Iron fouling, Corrosion prevention, Erosion and clogging

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IOM Manual

HBH SERIES

Heat Controller, Inc.

17

Water Quality Standards

Table 3: Water Quality Standards

Water Quality

Parameter

HX

Material

Closed

Recirculating

Open Loop and Recirculating Well

Scaling Potential - Primary Measurement

pH/Calcium Hardness

All

-

pH < 7.5 and Ca Hardness <100ppm

Method

Index Limits for Probable Scaling Situations -

(Operation outside these limits is not recommended)

Ryznar

All

-

6.0 - 7.5

Stability Index

If >7.5 minimize steel pipe use.

Langelier

All

-

-0.5 to +0.5

Saturation Index

If <-0.5 minimize steel pipe use. Based upon 150°F [66°C] HWG and

Direct well, 85°F [29°C] Indirect Well HX

Iron Fouling

Iron Fe

2+

(Ferrous)

All

-

<0.2 ppm (Ferrous)

(Bacterial Iron potential)

If Fe

2+

(ferrous)>0.2 ppm with pH 6 - 8, O2<5 ppm check for iron bacteria.

Iron Fouling

All

-

<0.5 ppm of Oxygen

Above this level deposition will occur.

Corrosion Prevention

pH

All

6 - 8.5

6 - 8.5

Monitor/treat as

needed

Minimize steel pipe below 7 and no open tanks with pH <8

Hydrogen Sulfide (H

2

S)

All

-

<0.5 ppm

At H

2

S>0.2 ppm, avoid use of copper and copper nickel piping or HX's.

Rotten egg smell appears at 0.5 ppm level.

Copper alloy (bronze or brass) cast components are OK to <0.5 ppm.

Ammonia ion as hydroxide, chloride,

nitrate and sulfate compounds

All

-

<0.5 ppm

Maximum

Maximum Allowable at maximum water temperature.

Chloride Levels

50°F (10°C)

75°F (24°C)

100°F (38°C)

Copper

-

<20ppm

NR

NR

-

<150 ppm

NR

NR

304 SS

-

<400 ppm

<250 ppm

<150 ppm

316 SS

-

<1000 ppm

<550 ppm

< 375 ppm

Titanium

-

>1000 ppm

>550 ppm

>375 ppm

Erosion and Clogging

Particulate Size and

Erosion

All

<10 ppm of particles

and a maximum

velocity of 6 fps [1.8 m/s].

Filtered for maximum

800 micron [800mm,

20 mesh] size.

<10 ppm (<1 ppm "sandfree” for reinjection) of particles and a maximum

velocity of 6 fps [1.8 m/s]. Filtered for maximum 800 micron [800mm,

20 mesh] size. Any particulate that is not removed can potentially

clog components.

Notes:

Rev.: 6/2/2010

• NR - Application not recommended.

• "-" No design Maximum.

• Closed Recirculating system is identified by a closed pressurized piping system.

• Recirculating open wells should observe the open recirculating design considerations.

Above the given limits, scaling is likely to occur. Scaling indexes should be calculated using the limits below

Scaling indexes should be calculated at 150°F [66°C] for direct use and HWG applications, and at 90°F [32°C] for indirect HX use.

A monitoring plan should be implemented.