Gravity | Gas Regulator
CORRECTIONS FOR GRAVITY For gases with specific gravity other than 0.6, apply correction factor from Table 3. Divide desired flow by factor to get equivalent flow of natural gas. Select regulator with appropriate capacity and discharge pressure.
Table 3. Gravity corrections
Gas
Example
gravity
Factor
Gas
0.4 0.6 1.0 1.5 2.0
1.22 1.00 0.774 0.632 0.547
Coke Oven
Natural
Air
Multiply regulator’s natural gas capacity by gravity factor to get its capacity with different gas.
Propane Butane
Bug screen above roof (if vent)
(Install gauge if used for cross-connection)
Bug screen above roof
½ " Vent or cross- connection line
15 D Recommended to ratio or other regulator to avoid hunting due to interaction between regulators.
1837D Needle valve
10D Minimum
3D Minimum to next fi tting
Weld ¾ " half coupling to top or side of pipe. Drill ¾ " hole thru pipe wall. Remove burrs from inside.
Minimum 3⁄8 " pipe or ¾ " OD tubing
7335
D — Pipe size (See Fig. 4)
Items in dotted lines not by Fives
Reducing coupling (not a bushing)
Drip leg or strainer
Figure 3. Detail of regulator and relief valve installation.
When necessary to dampen pulsation, use a fixed orifice, or an 1837D Needle Valve with internal bypass, which allows on-line "tuning out" of outlet pressure pulsation. Use pipe unions to simplify regulator removal for repair or replacement.
Bulletin 7335 Page 4
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