High Flow Regulators for Pipeline and Process Supply

Common questions

What makes a gas regulator high flow?

Its flow coefficient. Every regulator passes gas, but a high flow unit is built to pass a large volume while still holding its outlet setting as demand changes, on the PHF series through a balanced valve. For scale, the other regulators on this site that quote a Cv sit between 0.06 and 1.1, a Kv of roughly 0.05 to 0.95. The smallest PHF unit here is Kv 1.5 and the largest is 25. The three Rotarex in-line regulators on this page, the DC 50, the S 15 and the Mono S 15, do not publish a flow coefficient, so compare those on setting range and connection size.

What is the difference between Kv and Cv?

They measure the same thing, the flow a valve or regulator passes at a fixed pressure drop, in different units. Kv, the metric figure used in EN 60534, is cubic metres an hour of water at a 1 bar drop. Cv, the American figure, is US gallons a minute at a 1 psi drop. Multiply Cv by 0.865 to get Kv, or Kv by 1.156 to get Cv. Rotarex regulator pages elsewhere on this site quote Cv and the PHF pages quote Kv, so convert before comparing.

What is regulator droop, and when is a high flow unit the answer?

Droop is the fall in outlet pressure as the flow through a regulator rises. On a spring loaded unit the valve opens further to pass more gas, the spring relaxes and the setting drifts down, and near its capacity the regulator stops controlling and acts like a fixed orifice. If a unit holds its setting with one outlet open and loses it with three, that is droop, and the fix is a regulator whose Kv sits well above the flow you need. A common rule for self acting regulators is to use no more than about three quarters of the stated Kv.