Control Valve Sizing In Class Examples

On the pages that follow there are reprints of manufactures flow coefficients tables for a number of styles of valves. After that there are a number of valve data sheets with process conditions for different examples of valves to be sized. Using the data from the control valve data sheets and flow coefficient tables, size the valves. Include in your solutions, calculations for the following factors:

1.0 qm mass flow rate of fluid.

2.0 Cv approximate to initially estimate the size of the valve.

3.0 Manufactures data for the initial valve chosen: Cv selected, d, Fl, and Xt where applicable.

4.0 The piping geometry factor (Fp) for the initial valve chosen.

5.0 The valve recovery factor (Flp) if a liquid, or the pressure drop ratio factor (Xtp) if a compressible fluid, for the initial valve chosen, as needed.

6.0 The differential pressure maximum (Pm) if a liquid, or the gas expansion factor (Y) if a compressible fluid, for the initial valve chosen.

7.0 The Cv required for the initial valve chosen.

8.0 Is the initial valve the right choice or is the next larger size the right choice?

9.0 Reevaluation of Cv required with the next larger size, if needed.

Control Valve Sizing In Class Examples

Flow Coefficients (ANSI/ISA/IEC) from Fisher, Cat12, Page 1-89, Oct. 1988

Valve Design ES, Classes 125 to 600 with Equal Percentage Cage

Body size, Inches

Port Dia Travel Valve Opening—Percent of Total Travel

FLIn mm In mm 10 20 30 40 50 60 70 80 90 100

Cv

1 & 1-1/4 1-5/16 33.3 3/4 19 0.78 1.29 1.86 2.71 4.18 6.44 9.54 13.1 15.7 17.4 .95

1-1/2 1-7/8 47.6 3/4 19 1.54 2.52 3.57 4.94 7.41 11.6 17.2 23.5 28.7 33.4 .94

2 2-5/16 58.7 1-1/8 29 1.74 3.15 4.72 6.91 10.6 16.3 25.0 36.7 47.8 56.2 .92

2-1/2 2-7/8 73.0 1-1/2 38 4.05 7.19 10.6 14.5 21.2 31.6 45.5 64.2 77.7 82.7 .93

3 3-7/16 87.3 1-1/2 38 4.05 6.84 10.0 15.0 23.8 37.8 59.0 87.1 110 121 .89

4 4-3/8 111.1 2 51 6.56 11.4 17.3 27.0 42.2 66.4 103 146 184 203 .91

6 7 177.8 2 51 13.2 24.6 41.1 62.5 97.1 155 223 286 326 357 .86

8 8 203.2 2 51 18.8 33.6 53.6 79.8 114 168 242 345 467 570 .85

8 8 203.2 3 76 25.9 53.3 97.8 178 299 461 618 727 768 808 .85

1-1/2 1-5/16 33.3 3/4 19 0.88 1.35 1.89 2.52 3.68 5.52 8.13 12.0 16.5 21.0 .95

2 1-5/16 33.3 3/4 19 0.85 1.34 1.83 2.39 3.43 5.12 7.49 11.2 15.8 20.8 .91

2-1/2 1-7/8 47.6 3/4 19 1.43 2.37 3.34 4.76 7.25 11.3 17.3 24.2 31.8 40.3 .95

3 2-5/16 58.7 1-1/8 29 2.74 3.44 4.86 6.95 10.6 16.5 25.0 37.7 52.7 67.5 .94

4 2-7/8 73.0 1-1/2 38 3.96 7.14 10.6 14.5 21.1 31.7 48.0 69.7 95.6 121 .94

6 4-3/8 111.1 2 51 4.96 9.0 14.0 24.2 39.4 60.8 94.6 144 199 233 .91

XT

1 & 1-1/4 1-5/16 33.3 3/4 19 .754 .794 .763 .670 .652 .621 .630 .677 .718 .721 n/a

1-1/2 1-7/8 47.6 3/4 19 .674 .670 .694 .731 .706 .681 .698 .692 .789 .793 n/a

2 2-5/16 58.7 1-1/8 29 .863 .848 .849 .805 .782 .778 .792 .772 .847 .848 n/a

2-1/2 2-7/8 73.0 1-1/2 38 .747 .768 .745 .779 .764 .744 .783 .802 .841 .878 n/a

3 3-7/16 87.3 1-1/2 38 .768 .757 .761 .757 .758 .571 .754 .756 .758 .757 n/a

4 4-3/8 111.1 2 51 .722 .717 .739 .772 .738 .718 .718 .736 .792 .822 n/a

6 7 177.8 2 51 .723 .737 .767 .846 .803 .781 .808 .826 .847 .816 n/a

8 8 203.2 2 51 .874 .865 .769 .748 .731 .697 .712 .707 .697 .694 n/a

8 8 203.2 3 76 .825 .728 .681 .616 .678 .716 .735 .793 .825 .827 n/a

1-1/2 1-5/16 33.3 3/4 19 .858 .845 .867 .810 .833 .755 .776 .766 .766 .766 n/a

2 1-5/16 33.3 3/4 19 .844 .778 .803 .767 .791 .764 .764 .764 .755 .728 n/a

2-1/2 1-7/8 47.6 3/4 19 .664 .721 .741 .751 .679 .681 .678 .681 .748 .744 n/a

3 2-5/16 58.7 1-1/8 29 .753 .748 .756 .783 .766 .741 .736 .732 .737 .738 n/a

4 2-7/8 73.0 1-1/2 38 .792 .803 .770 .767 .760 .725 .703 .717 .763 .764 n/a

6 4-3/8 111.1 2 51 .842 .792 .778 .709 .723 .739 .729 .706 .719 .806 n/a

Note: Greyed areaa denotes Restricted Trim

Control Valve Sizing In Class Examples

Flow Coefficients (ANSI/ISA/IEC) from Fisher, Cat12, Page 1-75, Sept. 1995

Valve Design ED, Classes 125 to 600 with Equal Percentage Cage

Body size, Inches

Port Dia Travel Valve Opening—Percent of Total Travel

FL In mm In mm 10 20 30 40 50 60 70 80 90 100

Cv

1 & 1-1/4 1-5/16 33.3 3/4 19 0.78 1.54 2.20 2.89 4.21 5.76 7.83 10.9 14.1 17.2 .88

1-1/2 1-7/8 47.6 3/4 19 1.52 2.63 3.87 5.41 7.45 11.2 17.4 24.5 30.8 35.8 .84

2 2-5/16 58.7 1-1/8 29 1.66 2.93 4.66 6.98 10.8 16.5 25.4 37.3 50.7 59.7 .85

2-1/2 2-7/8 73.0 1-1/2 38 3.43 7.13 10.8 15.1 22.4 33.7 49.2 71.1 89.5 99.4 .84

3 3-7/16 87.3 1-1/2 38 4.32 7.53 10.9 17.1 27.2 43.5 66 97 120 136 .82

4 4-3/8 111.1 2 51 5.85 11.6 18.3 30.2 49.7 79.7 125 171 205 224 .82

6 7 177.8 2 51 12.9 25.8 43.3 67.4 104 162 239 316 368 394 .85

8 8 203.2 2 51 18.5 38.0 58.4 86.7 130 189 268 371 476 567 .85

8 8 203.2 3 76 27.0 58.1 105 188 307 478 605 695 761 818 .86

1-1/2 1-5/16 33.3 3/4 19 1.12 1.56 2.22 3.10 4.27 6.17 9.01 13.1 18.2 23.1 .91

2 1-5/16 33.3 3/4 19 0.92 1.42 2.09 2.84 4.11 5.83 8.58 12.8 18.5 24.3 .88

2-1/2 1-7/8 47.6 3/4 19 1.57 2.57 3.82 5.44 7.64 11.5 18.2 26.7 35.1 43.9 .89

3 2-5/16 58.7 1-1/8 29 1.75 3.11 4.77 7.07 10.7 17.0 27.9 41.5 58.0 70.7 .87

4 2-7/8 73.0 1-1/2 38 3.82 7.65 11.4 16.9 25.5 38.2 60.5 85.7 105 112 .89

6 4-3/8 111.1 2 51 5.40 10.1 15.8 26.7 45.2 71.2 111 169 232 274 .88

XT

1 & 1-1/4 1-5/16 33.3 3/4 19 .766 .614 .587 .667 .672 .687 .743 .760 .733 .667 n/a

1-1/2 1-7/8 47.6 3/4 19 .780 .735 .716 .715 .738 .727 .690 .685 .685 .679 n/a

2 2-5/16 58.7 1-1/8 29 .827 .834 .774 .727 .687 .684 .702 .736 .686 .687 n/a

2-1/2 2-7/8 73.0 1-1/2 38 .778 .702 .678 .677 .658 .654 .661 .665 .661 .660 n/a

3 3-7/16 87.3 1-1/2 38 .774 .706 .682 .635 .616 .602 .663 .693 .670 .675 n/a

4 4-3/8 111.1 2 51 .731 .650 .643 .645 .632 .625 .672 .742 .737 .716 n/a

6 7 177.8 2 51 .688 .680 .682 .709 .700 .720 .736 .744 .780 .778 n/a

8 8 203.2 2 51 .727 .623 .600 .588 .580 .587 .599 .611 .671 .724 n/a

8 8 203.2 3 76 .644 .654 .636 .611 .643 .615 .725 .809 .804 .807 n/a

1-1/2 1-5/16 33.3 3/4 19 .821 .864 .820 .703 .721 .679 .665 .639 .650 .700 n/a

2 1-5/16 33.3 3/4 19 .775 .744 .742 .707 .715 .714 .714 .641 .621 .649 n/a

2-1/2 1-7/8 47.6 3/4 19 .801 .756 .713 .677 .648 .672 .628 .635 .706 .710 n/a

3 2-5/16 58.7 1-1/8 29 .944 .840 .803 .757 .735 .642 .531 .613 .629 .702 n/a

4 2-7/8 73.0 1-1/2 38 .746 .700 .694 .669 .640 .627 .591 .644 .735 .813 n/a

6 4-3/8 111.1 2 51 .834 .834 .735 .654 .626 .613 .614 .610 .629 .695 n/a

Note: Greyed areaa denotes Restricted Trim

Control Valve Sizing In Class Examples

Control Valve Sizing In Class Examples

Control Valve Sizing In Class Examples

Control Valve Sizing In Class Examples

Control Valve Sizing In Class Examples

Control Valve Sizing In Class Examples