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Theory of pressure reducing regulators |
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Single Stage Pressure Regulators
Theory of pressure reducing regulators
Principle of Operation
Compressed gases are generally not useable until a
pressure regulator is incorporated to reduce the gas pressure to a workable level
that can be safely utilized in equipment and instruments. The basic design and
construction material differ according to the type and pressure of gas as well as
the type of application.
Pressure regulators are of two basic types.
Single Stage Pressure Regulators
Single stage pressure regulators reduce the cylinder gas pressure to the delivery
pressure in one (1) step. This one step pressure reduction results in a slight
change in delivery gas pressure as the cylinder pressure decays.
(In most cases, the delivery pressure will rise.) The single stage regulator is
a satisfactory and cost effective selection if slight variations in delivery pressure
and/or periodic adjustments are not detrimental to the application. In the case of
liquefied gases the cylinder pressure is constant and single stage regulators
are recommended.
Two-Stage Pressure Regulators
Double stage pressure regulators reduce the cylinder gas pressure to a working
level in two (2) steps. The cylinder gas pressure is reduced by the first stage
to a preset, intermediate level which becomes the gas pressure at the second
stage inlet. This allows the second stage to fine-tune the final delivery pressure.
Thus, double stage regulators provide a constant delivery pressure unaffected by
cylinder pressure decay.