The gas train has evolved significantly from a separately piped regulator, strainer, main safety shutoff valve, blocking safety shutoff valve and ratio regulator. The first step to simplify almost any gas train on industrial burners is to maximize the available gas pressure by combining the regulator and safety shutoff valve into one multifunctional valve. This allows the single multifunctional pressure regulator/shutoff valve to be sized for the total pressure drop consumed previously by the separate regulator and shutoff valve.
For example, a 4 million BTU/hr burner may typically have a gas train with 1 1⁄2" or 2" individual regulator and shutoff valves. By combining these functions into a multifunction gas valve, it would be expected that the gas train may only be required to utilize 3⁄4" or 1" multifunction valves. Rule of thumb: Many gas trains will include components that are two valve sizes smaller utilizing multifunctional components.
Servo pressure regulators used on multifunctional valves also provide superior regulator performance. Many conventional, direct-acting regulators not only reduce the pressure to the burner, but have a regulator droop between low and high fire. Multifunctional valves provide a constant pressure to the burner or control valve, with no regulator droop for superior burner performance.
If a standard regulator diaphragm were to rupture, the high gas pressure switch would trip the shutoff valve closed. The regulator would then vent gas through the regulator vent line out to atmosphere continuously. Should the regulator diaphragm burst in a modern combination gas valve, the high gas pressure switch would again trip the shutoff valve closed. In this case however, the regulator is not subject to any gas pressure once the valve closes. As a result there is no hazardous gas leakage to atmosphere. Simplify your gas train through the elimination of a regulator vent and subsequent roof penetration.
Customers utilizing multi-functional valves may eliminate one or more suppliers.
Customers benefit from a partnership that eliminates dissension between suppliers, as one manufacturer assumes responsibility for the compatibility of the various products and the overall performance of the total solution.
The latest advances in multifunction gas valve technology allow for simplified gas trains, while reducing the size, cost and complexity of a burner package including those on oven, dryer and furnace applications.
SidebarWhen simplifying your valve train, safety should not be compromised. Many multifunctional valve designs incorporate a hydraulic-relief system. The hydraulic pressure of the pump closes an internal valve and causes the safety shut-off valve to immediately close after the pump is depowered.
Hydraulic Relief For Safety
A hydraulic-relief system is an intrinsically safe system. No safety shut off valve incorporating a hydraulic-relief system is known to have failed in the open position.