Typical Cv, Cl value for Blowdown Valves*
Valve Size Flow Characteristic
Type Body Trim Cg Cl
D 1" 1/4" 51.6 31.1
D 1" 3/8" 117 29.1
D 1" 1/2" 192 29.5
D 1" 3/4" 388 31.5
D 2" 1/4" 51.6 31.1
D 2" 3/8" 117 29.1
D 2" 1/2" 192 28.1
D 2" 3/4" 407 28.9
D 2" 1" 672 28.3
D 2" 1-1/4" 1040 30.3
ET 1" 1-5/16" 559 32.5
ET 1-1/2" 1-7/8" 1170 32.8
ET 2" 2-5/16" 1970 33
ET 2-1/2" 2-7/8" 3210 32.3
ET 3" 3-7/16" 4440 32.7
ET 4" 4-3/8" 7540 33.6
ET 6" 7" 13800 35.1
ET 8" 8" 19200 33.8
Notes:

1, Data taken from Fisher Firstvue for
preliminary design.Final data should
be confirmed with manufacture data.

2, Cv=Cg/Cl

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