There are different delivery and supply
methods developed by the industrial gas industry to meet the needs of a wide
variety of industrial gas users. There are a number of parameters specifying
different combinations of production and distribution methods, which can
give the optimum service for a particular user at a given time. A complete
range of industrial gas supply options are provided by manufacturers and
suppliers of gas plants which include on-site cryogenic and non-cryogenic
systems, pipelines, liquid cylinders etc.
Factors Affecting the Choice of Supply and Delivery Options
There are different factors affecting the choice of supply and delivery
options for users of oxygen, nitrogen, hydrogen or other industrial gas
products. These are as follows:
- The average consumption rate
- Short term usage rate variation patterns
- Longer term usage rate variation patterns
- The purity of the final output required to meet the needs of customer
applications
- Location
- Cost
Categories of Gas Users
- Very small volume users
- Small to medium size customers
- Bulk Liquid Users
Supply and Distribution Modes
Cylinders
Cylinders are used by very small volume users. Especially those users who
use small quantity but in various locations or the application areas need to
be periodically located, the cylinders are preferred. Cylinder gases
distribution is basically a locally-focused business. Cylinders are majorly
distributed by independent distributors, which can be of varying sizes. They
buy gases in bulk liquid form from manufacturers and package the gases into
cylinders in their facilities. It is seen that cylinder gases, specially
oxygen and oxygen mixes are being widely used for home medical uses and
laboratories. Depending upon customers needs , the cylinders are delivered
to the customer's site or customers can return used cylinders and buy new
ones at a specialty store. Gas cylinders are used for relatively low gas
consumption requirements.
Storage
Tank and Vaporizer
Storage tanks and vaporizers are usually preferred by the small to medium
size customers. They use vaporized liquid as their source of oxygen,
nitrogen and argon. In such mode of distribution, trucked-in bulk liquid
product is transferred from delivery vehicles to a storage tank on the
customer's premises, then vaporized into a local distribution system. In
other words, storage tanks or vaporizers are specially designed
super-insulated containers to store or transport gases in liquid form or
cryogenic gases. The cryogenic storage tank and vaporizer system is
installed on the user site usually near the usage point and is referred to
as a customer station, which can typically hold as little as about 300
gallons or as much as 15,000 gallons. These tanks provide a reserve gas
supply and enable much greater self-sufficiency than cylinders.
Tube Trailers
Tube trailers are used to meet large but temporary requirements. Tube
trailer are a cluster of high pressure cylinders permanently mounted on a
wheeled platform. Tube trailers are usually demanded in situations of
process development, testing of new equipment, and plant maintenance
demands, to provide an extra level of backup to delivery systems that serve
very crucial operations. However, such type of distribution is comparatively
more expensive than liquid deliveries or on-site gas production.
Gas
Pipelines
Gas pipelines are used in on-site supply distribution. For large,
continuous and uniform supply of gases, gas production plants are erected on
or close to the customer's site and these plants are linked directly to the
customer through in-plant or local multi-plant distribution pipelines.
Pipeline Components
Gas pipelines have a number of components which ensure the reliability and
efficiency of gas distribution.
- Pipes: Pipes are made of steel or metal which are covered
with a specialized coating and can measure anywhere from 6 to 48 inches
in diameter
- Compressor Stations: It is very essential that the gas that
flows though a pipeline must be able to maintain a regular temperature.
Gas is highly pressurized, especially natural gas as it travels through
an interstate pipeline. Similarly cryogenic gas must flow at the
required cryogenic temperature. Compression of gas is required
periodically along the pipe. Hence compressor stations are placed,
usually at 40 to 100 mile intervals along the pipeline, to reduce the
volume of the gas and push it through the pipe. The gas enters the
station, where it is compressed by either a turbine, motor, or engine.
- Metering Stations: Metering stations are placed along gas
pipelines at regular intervals. These stations allow pipeline companies
to measure the flow of gas along the pipeline, manage and monitor the
natural gas in their pipes.
- Valves: Valves are integral component of pipelines , which
work like gateways and they are kept open to allow gas to flow freely.
Valves are also needed to stop gas flow along a certain section of pipe.
Supply
of Industrial Gases 
