Negative Regulation Gas Train Operation Overview

Negative Regulation Gas Train Operation Topics
The difference between positive and negative regulation.
How negative regulation technology works.
Size and location of regulators.

[@nebbrooklyn5966]

Great video thanks

[@DThinker123]

Some comments: With regards to the Sigma 848 diagram explanation- Pint is not the signal pressure, it's actually the Inlet pressure. From my experience inlet pressure on combination valves does not have to be stable, so long as it is above the minimum pressure (typically 6" WC). I've seen inlet pressure swing from 16" to 6" with out impacting CO2 % at all. Note- with a premix blower (blower located downstream of the venturi) you will not need the rubber signal hose since pressure upstream of the venturi will be equal to atmospheric pressure. Another benefit of leaning out the mixture at low firing rates- in the event of restricted air flow, your furnace will fail lean versus rich causing high CO concentrations.

[@lastnameavailableok]

Great video there FIA Inc. Question; The pilot air connection to the reg will pull a negative pressure signal, mixing with main gas through to burner head ('flows through the zero reg as there is a 'small calibrated' hole in teh diaphragm?) Or is pilot air only acting on the regulator diaphragm and 'stops' (not 'flow through'), and then main gas flow is now initiated? And can the fan is 'pulling' the main gas through without a negative pressure on the pilot air signal?