Page 97 - GRINNELL Mechanical Products Catalogue

CiRCuiT BALANCiNG vALvES
MATERIAL SPECIFICATIoNS Body
• Sizes 15mm – 50mm (1⁄2" – 2") solder or NPT threaded connection: brass-resistant to dezincification (DZR)
• Sizes 65mm – 300mm (21⁄2" – 12"), grooved or flanged connection: Cast Iron conforming to ASME ANSI B16 .5
Valve Stem & Disc
• Brass resistant to dezincification (DZR)
o Ring
• EPDM E
Handwheel
• Thermoplastic
For accessories and replacement parts contact GRINNELL Mechanical Products for details .
Valve Sizing
All balancing valves are sized to perform in a normal operation range between 25% and 100% of the full open position, at a minimum differential pressure between 0 .3m – 0 .9m (1 – 3 ft.) of water . It is recommended that for improved accuracy, the valve is set to open 70%+ .
When maximum flow is known but a pressure drop through the balancing valve is unknown, select a balancing valve
for a maximum pressure drop of 0 .6m (2 ft.) water 5 .7 kPa (0.8 psi) in the full open position as shown in the table to the right .
Accurate flow measurement requires that the velocity distribution near the balancing valve remains constant, regardless of the total flow through the pipe . Fittings, such as elbows and tees, disturb the normal flow profile which is established through straight pipe . Pumps create even greater disturbances . Failure to allow water flows around fittings and pumps to normilise can affect measuring accuracy by as much as 20% when the valve is in the fully open position . Minimum lengths (diameters, D) of straight pipe before and after the balancing valve prevent these errors .
Valves are designed for vertical, horizontal, or inclined installation .
1⁄2 3⁄4 1 1-1⁄4 1-1⁄2 2 2-1⁄2 3 4 5 6 8 10 12
0.5 - 4.1 4.1 – 6.1 6.1 – 9.2 9.2 – 20 20 – 29 29 – 40 40 – 102 102 – 125 125 – 210 210 – 300 300 – 430 430 – 760 760 – 1350 1350 -1500
Thread
CB800 Circuit Balancing Valves
Tech Data Sheet: G450
Minimum Pipe Diameters from Fittings
3D 2D Pump 10D 2D
Size
mm
Inches
Flow Rate LPH GPM
Connection Type
15
100 - 1000
20
1.0k – 1.5k
25
1.5k – 2.3k
32
2.3k – 5.0k
40
5.0k – 7.2k
50
7.2k – 10k
65
10k - 25k
80
25k – 31k
100
31k – 50k
125
50k – 76k
Flanged or Grooved
150
76k – 108k
200
108k – 190k
250
190k – 340k
300
340k – 377k
Refer to back cover for country-specific customer care numbers.
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CirCuit BalanCing ValVes