These valves use two springs in order to set the high and low fire settings. One spring (min.) surrounds the solenoid and is always in contact with the diaphragm assembly. The other spring (max.) is located above the plunger. With zero voltage applied, the minimum and maximum spring's down force, along with plunger weight, pushes down on the diaphragm thereby setting a regulated high fire. A separate pressure regulator is not required.
As voltage is applied, the plunger pulls up sufficiently until all plunger weight and maximum spring force is removed. The pressure is now controlled with the minimum spring setting giving a regulated low fire condition.
Note: This product should be installed by a licensed gas fitter.