LP regulator at altitude
Does a LP regulator maintain a constant 11"+/- WC pressure as altitude increases? It would seem that as atmospheric pressure decreases that less force would be exerted on the diaphragm thereby changi...
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Vapor pressure or container pressure will not exceed 200 psia unless the temperature is above 100F, this happens in some places but not all. ie, container pressure is likely to be way less than 200 psi, especially if there is a need for heat and then the vapor pressure will be less than 100 psia (60F).
The main reason for the vent is to allow the diaphragm to move.
Let's say the the spring tension and atmos pressure is such that the regulator can operate between 9 and 14" wc. At 9" the linkage has the input OPEN and at 14" the linkage is so that the input is CLOSED. Ever heard em hum as the linkage moves open and shut rapidly?
Now lower the atmos pressure, the diaphragm now is slightly further away which causes the linkage to be closer to CLOSED. At the same flow rate this may be lower pressure ie it operates at 9-13" wc.
Pressure drop test done at 8" insures the inlet of the regulator is OPEN.
The main reason for the vent is to allow the diaphragm to move.
Let's say the the spring tension and atmos pressure is such that the regulator can operate between 9 and 14" wc. At 9" the linkage has the input OPEN and at 14" the linkage is so that the input is CLOSED. Ever heard em hum as the linkage moves open and shut rapidly?
Now lower the atmos pressure, the diaphragm now is slightly further away which causes the linkage to be closer to CLOSED. At the same flow rate this may be lower pressure ie it operates at 9-13" wc.
Pressure drop test done at 8" insures the inlet of the regulator is OPEN.
