| 摘要 |
There is disclosed a gas regulator valve of the conventional, diaphragm pressure controlled operation which has an internal bleed cavity and a bleed passageway communicating through a snap-acting valve responsive to a heating demand electromagnet and a regulator valve that responds to the regulator outlet pressure. This valve structure is modified in accordance with this invention to provide a step opening characteristic. The step opening characteristic provides an initial low pressure supply of gas and, within a constant and relatively short time interval thereafter, an increased gas supply which is maintained at a substantially constant pressure by the regulator valve. The valve structure is modified to provide the stepped operational characteristic by a by-pass passageway from the inlet to the bleed cavity, bypassing the bleed orifice. The bypass passageway includes a valve with a diaphragm valve actuator in an internal cavity within the valve housing. The operator diaphragm subdivides this cavity into first and second pressure chambers, one chamber in open communication with the bleed chamber and the second chamber communicating through a delay orifice with the bleed passageway.
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