Gas cabinet

These gas cabinets are used for inert, non-reactive and non-toxic gases. There are automatic gas cabinets also available and thus these cabinets are less useful when compared to automatic cabinets.

These cabinets are available for corrosive, toxic and reactive gases. They provide safe and clean delivery of ultra-high purity gases. Such systems are designed to monitor a huge number of facility inputs and process sensors as per requirements.

These gas cabinets are useful when uninterrupted gas flow is required. Auto changeover gas cabinets can be defined by mass or pressure inputs. There is software also available for multiple cylinder scales on each joint or bank. Purge down and purge up processes can also be performed without any interruption of connected cylinders.

Gas cabinets may be distinguished by the types of valves used to control flow. Manual valves. Valves are manually adjusted or deployed via a control knob, lever, or other manual device. Solenoid valves. Valves are opened and closed via a solenoid magnet deployed by an electrical signal. Air pilot valves. Valves are deployed via a pneumatic signal.

Ports are openings in the manifold or distribution system where the inlet and outlet connections are produced. Each opening is either an inlet (supply) port or an outlet port. The number of each corresponds to the requirements of the application. The quantity of supply ports specifies the number of independent fluid supplies that could be interfaced with the manifold or manifold system.

The number of outlet ports establishes the number of outlets in the system. This is frequently specified as number of ports or valves that are or can be attached to the manifold. For example, an 8-point manifold has 8 ports or valves. Ports are sized based roughly on tube or pipe size with some important choices. For industrial gases it is possible to purchase manifolds made of Stainless steel pipe or copper and brass although both these materials are giving way to Stainless steel tubing. (Note differences between Tubing and Pipe). Connection choices might be NPT, VCO, Flare or other types.

For gas service that is "Clean For Oxygen Service (CFOS)" or for Ultra Pure service, manifolds and change over assemblies are typically made from 1/4" OD, 316 L, Electropolished tubing (the ID is Electropolished). The fittings used for ports and other connections are exclusively the "VCR" fitting. Training is needed to properly handle and install VCR connections using a variety of non-resuseable crushable metal gasket materials. Metal gaskets are essential in order to achieve high helium leak ratings.

Pressure describes the amount of force exerted on a system by the contained and pressurized gas. Most compressed gases will not exceed 2,000 to 2,640 pounds per square inch gage (psig), but some can reach pressures of 6,000 psig. The system's weakest point determines the pressure limit, so any parts weakened by heat, corrosion, or stress may potentially lower the maximum pressure of the system or cause the vessel to rupture. Many times this is at the point of welds.

Flow rate details the maximum rate of flow of the gas through the operation, typically measured in standard cubic feet per minute (scfm).

Temperature range is the full mandated range of safe ambient or fluid operating temperatures, given in degrees Fahrenheit or degrees Celsius.

Size dimensions specify the physical size of the gas cabinet, distribution system, or its components. Cabinet size - Indicates the physical size of the gas cabinet or the body of the distribution system. Port/tube size - Indicates the physical size of the tubing or exhaust port connections in the system, typically given in inches based on a sizing standard such as National Pipe Thread (NPT). Sizing is important, as an undersized tube line will result in high pressure drops, while an oversized line will be unnecessarily expensive to install.

A light and fairly corrosion resistant metal which is most often anodized for increased corrosion and wear resistance. Aluminum is never used for tubing or fittings in modern industrial gas control & distribution systems since 316L stainless steel (optimum choice) is so available. Aluminum is not an ideal choice for purity. Aluminum in any form is never used for ultra pure industrial gas systems.

A soft, ductile metal with low hardness and excellent corrosion resistance. Copper is used commonly in tubes and pipes for its inertness and resistance to corrosion. Copper can be used for low air, oxygen and other inert non-critical gases such as medical CFOS systems. For ultra pure gasses 316L Stainless steel remains the optimum choice for many reasons.

Any of numerous thermoplastic or thermosetting polymers of high molecular weight. Different grades (such as nylon, acetal, and polycarbonate) have varying properties, but most have strong chemical and corrosion resistance.

General purpose industrial metal with high physical strength and hardness. Steel is typically coated or finished to increase its corrosion resistance properties. Steel is used in the petroleum and petro-chemical industries.

316L Stainless steel became industry standard for fittings, piping and controls in gas cabinets and distribution systems in the early 1980s. The material is further improved by electropolishing to render wetted surfaces extremely impervious to the most reactive gasses creating a non-shedding surface. A large industry has grown around supplying these ultra-specialized components and materials.