I don't do much in the way of “rack” refrigeration. However, I recently had a conversation with experienced rack refrigeration tech Jeremy Smith, and he got me thinking about EPR valves. I've heard EPR (evaporator pressure regulator) valves called suction regulators or hold back valves. In essence, they hold back against the suction line to […]

To maintain combustion (burning), you need three things: fuel, heat, and oxygen. If you have all three in the proper proportion, you can maintain a continuous state of combustion. Remove one (or reduce one sufficiently), and the triangle of combustion can collapse. In a common natural gas (NG) furnace, the heat is the igniter, the […]

We've been getting many questions on micron gauges that are ”going haywire” or reading in the micron range, even at atmospheric pressure. First, micron gauges measure absolute pressure, so you can’t ”zero” them out. They use tiny, very sensitive sensors that are calibrated to air, not refrigerant, so anytime refrigerant gets into the gauge, it's […]