Gas Manifolds

Wall mounted gas delivery panels

Gas supply panels operate in a similar way to cylinder pressure regulators. The difference is that they are mounted on the wall and connected to the cylinder with a hose or pigtail, whereas the cylinder regulator is connected directly onto the cylinder. The panels are the more typical option to select for use in a gas store where the gases are piped to the point of use with gas delivery pipe work. The cylinder regulators tend to be used if the cylinder is used at the instrument or in the laboratory.

Gas manifolds are generally used in combination with a point-of-use regulator, which is wall-mounted inside the laboratory where the gas is being used at the analytical instrument. For this reason, the most common panels are single-stage pressure reduction panels because there is a second stage of pressure reduction at the point-of-use regulator in the laboratory.

Typical gas manifold applications include

• Calibration gas supply and instrumentation gas supply in cylinder gas stores that are close to manned operations
• Automotive emissions testing laboratory gas supply rooms
• General laboratory gas supply rooms for high purity gases

Continuity of supply

At Coregas, we can help you go digital to ensure continuity of supply. We offer gas supply panels with alarm signals that are connected to our online system using 3G mobile phone-type communications. The alarm triggers delivery of a new product and also sends a message to the end user.

If a continuous flow of gas is required and flow interruption during cylinder change over is not acceptable, then an automatic changeover panel should be specified.

Product selection guidance

Select chrome-plated brass for the following gases:

• High purity inert gases such as Helium 5.0 grade or Nitrogen 5.0 grade
• High purity flammable gases such as Hydrogen 5.0 grade or Methane 3.5 grade
• Inert calibration gas mixtures such as 8% Oxygen in Nitrogen
• Flammable calibration gas mixtures that do not contain corrosive components such as 10% Methane in Nitrogen

Select stainless steel for the following gases and usage environments:

• Offshore for all gases (salt sea spray would corrode a chrome-plated brass regulator)
• Refinery and natural gas processing operations for all gases (H₂S in the air will would corrode a chrome-plated brass regulator)
• Water treatment facilities and biogas reactors for all gases (H₂S in the air will would corrode a chrome-plated brass regulator)
• Pharmaceutical or food processing applications where hygiene is critical
• Calibration gas mixtures that contain any concentration (ppb, ppm or % level) of corrosive components such as NOx, SO₂, H₂S
• Pure carbon monoxide, or mixtures containing carbon monoxide, to avoid the potential for metal carbonyl formation through reactions with the chrome-plated brass regulator metallic coating

Automatic changeover panels

For uninterrupted gas supply from cylinders, it is recommended to use an automatic gas changeover valve unit. They switch from an empty cylinder to a full one when required. The empty cylinder can then be replaced and the system can be reset by the operator.

Typical applications include:

• Automatic switch over of CEMS system calibration gas mixtures to ensure an uninterrupted supply of calibration gas and to avoid the risk of non-calibrated emissions monitoring readings. This is especially useful at remote site locations or unmanned sites.
• Automatic switch over of ambient air quality monitoring system calibration gas mixtures to ensure an uninterrupted supply of calibration gas and to avoid the risk of non-calibrated air quality readings. This is especially useful because many of these air quality monitoring stations are at remote, unmanned sites.
• Automatic switch over of process control instrumentation calibration gas mixtures to ensure an uninterrupted supply of calibration gas and to avoid the risk of non-calibrated process control instrument readings. This is especially useful for instrumentation shacks in remote site locations or unmanned sites.
• Automatic switch over of GC carrier gases (Helium 5.0 grade or Hydrogen 5.0 grade), zero gases (Nitrogen 5.0 grade or Zero Air) or detector instrumentation gases (Helium 5.0 grade, Hydrogen 5.0 grade or Zero Air) to ensure an uninterrupted supply and to avoid the risk of non-calibrated analyser readings. This is especially useful for instrumentation located in remote corners of a large site or unmanned sites.

Product selection guidance

Our automatic gas changeover panels can be supplied with a single-stage of pressure regulation, or with two stages. In large laboratory installations, it is common to use wall-mounted point-of-use regulators downstream of the changeover unit at the location where the gas flows to the analytical instrument in the laboratory. In this case, where it will generally be sufficient to specify a single stage of pressure regulation in the changeover unit, model BM55-2U applies.

Another common application of the changeover unit is in unmanned process control instrumentation shacks, CEMS gas and instrument shacks, and air quality monitoring stations. In these situations, the cylinders and the instrumentation are located within a few metres and when using high purity gases or instrumentation gases where continuous flow at a stable pressure is required, the second stage of pressure regulation is generally built in to the automatic changeover panel so model BM56-2U is recommended. For use with calibration gas mixtures in such applications, it will also be recommended to specify dual stage pressure regulation because, unlike cylinder mounted calibration gas regulators, the operator is not present to adjust the outlet pressure as the content in the cylinder reduces.