Handbook of air conditioning and refrigeration / Shan K

CHAPTER 7
WATER SYSTEMS
7.1 FUNDAMENTALS 7.2
Types of Water System 7.2
Volume Flow and Temperature
Difference 7.4
Water Velocity and Pressure Drop 7.5
7.2 WATER PIPING 7.7
Piping Material 7.7
Piping Dimensions 7.7
Pipe Joints 7.13
Working Pressure and Temperature 7.13
Expansion and Contraction 7.14
Piping Supports 7.15
Piping Insulation 7.15
7.3 VALVES, PIPE FITTINGS, AND
ACCESSORIES 7.16
Types of Valves 7.16
Valve Connections and Ratings 7.17
Valve Materials 7.18
Piping Fittings and Water System
Accessories 7.18
7.4 WATER SYSTEM PRESSURIZATION
AND THE PRESENCE OF AIR 7.19
Water System Pressurization
Control 7.19
Open Expansion Tank 7.20
Closed Expansion Tank 7.21
Size of Diaphragm Expansion Tank 7.21
Pump Location 7.23
Air in Water Systems 7.23
Penalties due to Presence
of Air and Gas 7.24
Oxidation and Waterlogging 7.24
7.5 CORROSION AND DEPOSITS IN
WATER SYSTEM 7.25
Corrosion 7.25
Water Impurities 7.25
Water Treatments 7.26
7.6 CLOSED WATER SYSTEM
CHARACTERISTICS 7.27
System Characteristics 7.27
Changeover 7.28
7.7 CENTRIFUGAL PUMPS 7.30
Basic Terminology 7.30
Performance Curves 7.32
Net Positive Suction Head 7.33
Pump Selection 7.33
7.8 PUMP-PIPING SYSTEMS 7.34
System Curve 7.34
System Operating Point 7.34
Combination of Pump-Piping
Systems 7.35
Modulation of Pump-Piping
Systems 7.36
Pump Laws 7.37
Wire-to-Water Efficiency 7.37
7.9 OPERATING CHARACTERISTICS OF
CHILLED WATER SYSTEM 7.38
Coil Load and Chilled Water
Volume Flow 7.38
Chiller Plant 7.39
Variable Flow for Saving Energy 7.40
Water Systems in Commercial
Buildings 7.40
7.10 PLANT-THROUGH-BUILDING
LOOP 7.40
Bypass Throttling Flow 7.40
Distributed Pumping 7.41
Variable Flow 7.41
7.11 PLANT-BUILDING LOOP 7.43
System Description 7.43
Control Systems 7.43
System Characteristics 7.45
Sequence of Operations 7.46
Low �T between
Chilled Water Supply and Return Temperatures
7.49
Variable-Speed Pumps Connected in
Parallel 7.49
Use of Balancing Valves 7.49
Common Pipe and Thermal
Contamination 7.51
7.12 PLANT-DISTRIBUTED PUMPING 7.52
7.13 CAMPUS-TYPE WATER
SYSTEMS 7.53
Plant-Distribution-Building Loop 7.54
Plant-Distributed Building Loop 7.56
Multiple Sources-Distributed
Building Loop 7.57
Chilled and Hot Water Distribution
Pipes 7.58
7.14 COMPUTER-AIDED PIPING DESIGN
AND DRAFTING 7.58
General Information 7.58
Computer-Aided Drafting
Capabilities 7.58
Computer-Aided Design
Capabilities 7.59
REFERENCES 7.60
7.1