A
gas regulator or a pressure regulator or simply regulator is a device that
automatically cuts off the flow of gas at a certain pressure. Widely used in
gas plants or gas systems, regulators are meant to reduce the pressure from
a high pressure source to a safe working pressure for use. It is a very
essential equipment to bring about a positive control of the pressure in a
gas stream. A safety tool, it reduces high-pressure gas in a cylinder or
process line to a lower level that is usable and maintain pressure in a gas
delivery system. In other words, regulators are used to control delivery
pressure only. Regulators are suited to most industrial grades of gases and
fluids up to 99.99% purity (which includes helium, hydrogen, acetylene,
argon, oxygen and CO2).
Basic Operating Components
In gas pressure regulators, there are three basic operating components,
which work together to obtain pressure reduction. They are as follows:
- A loading mechanism: The setting of the regulator
delivery pressure depends on loading mechanisms. The loading mechanism
usually make use of a spring and with turning of the regulator's hand
knob, the spring is compressed. Force is applied on the spring and
transferred to both the sensing element and the control element to
achieve the outlet pressure.
- A sensing element: Sensing elements imply the
components which sense the force put on the spring, which in turn set
the delivery pressure. A diaphragm, either constructed of elastomers or
metal, is usually as the sensing element and it is this element which
communicates this change in force to the control element.
- A control element: The control element in gas
regulator is the valve that leads to the reduction of inlet pressure to
outlet pressure. With the turning of the gas regulator's hand knob,
there is compression of the loading mechanism, which displaces the
sensing element (diaphragm) which in turn pushes on the control element,
causing it to move away from the regulator's seat, and provide the flow
and pressure required.
Parts of a Typical Regulator
Types of Regulators
There are four main types of gas pressure regulators:
- Line Gas Pressure Regulators: Line regulators are
point-of-use gas pressure regulators. They serve low-pressure pipelines,
used with high-pressure cylinder regulators. The line pressure
regulators limit the inlet pressure from 250 to 400 psig.
- General-purpose Gas Pressure Regulators: It is a common type
of gas pressure regulators, specially designed for economy and
longevity, and preferred for noncorrosive general plant, pilot plant,
and maintenance shop applications.
- High-purity Gas Pressure Regulators: They provide diffusion,
resistance, and easy cleanup. inboard diffusion eliminated by metal
diaphragms and high-purity seats and seals. · Special service gas
pressure regulators: Specialized regulators are specifically constructed
for specialized applications like high-pressure, ultra high-pressure,
oxygen, acetylene and fluorine service, and corrosion service.
Regulators: Design Types
Regulators are generally classified into 3 design types types:
- With no gauge: They are economical general purpose regulators
and here monitoring of the gas supply and outlet pressure is not needed.
- One gauge: These regulators show the inlet pressure only but
can be supplied to show the outlet pressure instead.
- 2 gauges: This model shows accurate pressure reading of both
inlet and outlet pressures and is the most popular design used today.
On the basis of the above design types, gas regulators can be
classified as follows:
- Single-stage Regulators: They give good pressure and flow
characteristics. Suitable for short run analytical work, engineering and
industrial applications, these regulators are available in a range of
inlet and outlet pressures (up to 6000 psi) to suit most gases.
- Two-stage Regulators: Also referred to as multi-stage
regulators, they have all the features of single-stage regulators.
Besides that with the two gas reduction chambers, they provide
additional safety and specific control over the complete inlet pressure
range. Multi-stage regulators are capable of working with cylinder
pressures up to 300 Bar with safety and precision control. They provide
the ultimate answer to gas pressure requirements, and can be found in
many diverse applications including gas plants, life support systems,
laboratory supply systems, food and drink processing, and high tech
manufacturing.
Buying Tips
With the increasing number of different types of regulators available and
the endless lists of specifications in manufacturer's literature, there is a
problem in selecting the right regulator for the right purpose. The Natural
Gas Regulators Application Guide and the Industrial Regulators Application
Guide is designed to help you in making a right choice for a regulator that
fits your application's specific needs. The following specifications can be
evaluated:
- Product description
- Available sizes
- Maximum inlet and outlet pressures (operating and emergency)
- Flow capacity · End connection styles
- Outlet pressure ranges
- Construction materials
- Temperature capabilities
- Accuracy
- Pressure registration (internal or external)
Gas
Regulators
