Quite often, high accuracies are required, possibly ±0.1-0.2 psi. Regulating valves used in conjunction with spring or dome loaded pilots enable the achievement of this accuracy. The pilots act as narrow band proportional controllers.
Flow control, level control or temperature control can be accomplished using dome loaded regulators quite easily. Integration with a computer system is very simple. Using a pilot provides a high degree of accuracy.
The Burling Model OR-A can be utilized as a pneumatic output temperature controller by establishing a temperature set point, and used in conjunction with a Burling BD dome loaded regulator one can achieve control of the cryogenic fluid so that only gaseous product is introduced into the plant.
Spring Loaded Differential Pressure Regulators are used to maintain lubrication or seal media on rotating or reciprocating equipment. The differential is maintained relative to internally sensed turbine or compressor pressures.
Pressure building regulators used to maintain pressure in vapor space above cryogenic liquid in Dewar vessels. By using a light spring with low “droop” assisted by gas pressure, a highly accurate pressure of 275 psig or more is attained.
Set-point is capable of accuracies of ± 2 psig.
By using a small stabilizing regulator, a simple Dome Loaded configuration can achieve ± 1-2 psig accuracy, either upstream or downstream.
By using a simple spring loaded back pressure regulator, constant pump discharge pressure can be generated regardless of demand.
By using a spring-loaded regulator with remote sensing, constant discharge pressure after a filter can be achieved regardless of cake buildup.
Accuracies of ± 1-2 psig are achievable with dome loaded regulators. If greater accuracy is required pilot operated dome loaded regulators are utilized. Since pilots are narrow band proportional controllers, accuracies of 2”-3” of W.C. are possible. Pilots can be dome loaded as well as spring loaded.
Typical pilot actuated dome loaded regulator for regulator accuracies of ± 0.1-0.2
With the selection of the sensing element such as a pressure transducer, pH meter, level control or other, coupled with a controller and I/P (extended range, if necessary) the functionality of a control valve is accomplished.