DG Series Regulators
7
Table 7. Dimensions and Estimated Weight
BODY DIMENSION, mm / In. WEIGHT, Kg / Lbs
A B C D E
DN NPS DOA 180 DOA 330 DOA 180 DOA 330 DOA 180 DOA 330 PN16 PN25/40 CL150 CL300 DOA 180 DOA 330 DOA 180 DOA 330
Pressure Reducing Regulator
25 1 680 / 26.8 685 / 27 580 / 22.8 585 / 23 115 / 4.53 120 / 4.72 184 / 7.24 197 / 7.76 184 / 7.24 197 / 7.76 180 / 7.09 330 / 13 29 / 63.9 38 / 83.8
50 2 707 / 27.8 712 / 28.0 591 / 23.3 596 / 23.5 127 / 5.00 132 / 5.20 254 / 10.0 267 / 10.5 254 / 10.0 267 / 10.5 180 / 7.09 330 / 13 39 / 86 48 / 105.8
80 3 753 / 29.6 758 / 29.8 609 / 24.0 614 / 24.2 145 / 5.71 150 / 5.91 298 / 11.7 317 / 12.5 298 / 11.7 317 / 12.5 180 / 7.09 330 /13 59 /130 68 /150
100 4 816 / 32.1 801 / 31.5 639 / 25.2 624 / 24.6 175 / 6.89 180 / 7.09 352 / 13.9 368 / 14.5 352 / 13.9 368 / 14.5 180 /7.09 330 /13 83 /183 91.5 / 202
Backpressure Regulator
25 1 700 / 27.6 684 / 26.9 638 / 25.1 622 / 24.5 172 / 6.77 177 / 6.97 184 / 7.24 197 / 7.76 184 / 7.24 197 / 7.76 180 / 7.09 330 / 13 29.5 / 65.0 38 / 83.8
50 2 739 / 29.1 725 / 28.5 656 / 25.8 642 / 25.3 192 / 7.56 197 / 7.76 254 / 10.0 267 / 10.5 254 / 10.0 267 / 10.5 180 / 7.09 330 / 13 40.5 / 89.3 48 / 105.8
80 3 796 / 31.3 780 / 30.7 691 / 27.2 675 / 26.6 225 / 8.86 230 / 9.10 298 / 11.7 317 / 12.5 298 / 11.7 317 / 12.5 180 / 7.09 330 / 13 59.5 / 131 68 /150
100 4 855 / 33.7 846 / 33.3 727 / 28.6 718 / 28.3 262 / 10.3 267 / 10.5 352 / 13.9 368 / 14.5 352 / 13.9 368 / 14.5 180 / 7.09 330 / 13 83.5 / 184 92 / 203
Table 8. Maximum Differential Pressure of PRV
GAS LIQUID
Ratio range of inlet pressure over setting pressure: 1.2:1～20:1
Ratio range of inlet pressure over setting pressure:
1.2:1～10:1, need to meet the following at the same time:
Differential Pressure of PRV≤ (Inlet pressure + standard atmosphere pressure) x
Recover Factor Km(Km=0.7).
Table 9. Wide-Open Flow and IEC Coefficient
BODY SIZES WIDE-OPEN FLOW COEFFICIENT VALVE RECOVERY FACTOR, Km
DN NPS CvCg
25 1 16 529 0.7
50 2 59 1797 0.7
80 3 148 4345 0.7
100 4 240 6590 0.7
DG Series PRV is a direct-operated pressure reducing regulator. When operating, fluid flows from the inlet chamber, up
through the seat ring and cage and exits the outlet chamber. Downstream pressure is registered at the underside of the
diaphragm through an external sensing line that is connected to the lower diaphragm casing. The pressure under the actuator
diaphragm is balanced by the spring force acting at the topside of the diaphragm, through the action of the actuator stem,
the valve plug moves to or away from the seat ring to achieve pressure reducing and retaining. Downstream pressure is set by
turning the adjusting screw.
When downstream flow demand decreases, downstream pressure increases and the pressure registered under the actuator
diaphragm also increases. Spring force moves the diaphragm upward and the valve stem together with the valve plug move
towards the seat ring, decreasing fluid flow and downstream pressure is maintained at a new equilibrium state.
When downstream flow demand increases, downstream pressure decreases and the pressure registered under the actuator
diaphragm also decreases. Spring force now moves the diaphragm downward and the valve stem together with the valve plug
move away from seat ring, increasing fluid flow and downstream pressure is maintained at a new equilibrium state.
DG Series BPV is a direct-operated backpressure regulator. When operating, fluid flows from the inlet chamber through the
seat ring and cage and exits on the outlet chamber. Inlet pressure is registered at the underside of the diaphragm through an
external sensing line that is connected to the lower diaphragm casing. The pressure under the actuator diaphragm is balanced
by the spring force acting at the topside of the diaphragm. Through the action of the actuator stem, the valve plug moves to
or away from the seat ring to achieve pressure retaining. Upstream pressure is set by turning the adjusting screw.
When the inlet pressure is above the set pressure, the pressure registered at the actuator diaphragm increases. Spring force
moves the diaphragm upward and the valve stem together with the valve plug move away from seat ring, increasing fluid flow
and then it opens the backpressure regulator. Inlet pressure is maintained at a new equilibrium state.
When the inlet pressure is below the set pressure, the pressure registered at the actuator diaphragm decreases. Spring force
now moves the diaphragm downward and the valve stem together with the valve plug move towards the seat ring, decreasing
fluid flow and then it closes the backpressure regulator. Inlet pressure is maintained at a new equilibrium state.
3. Principle of Operation
