Understanding the Two Types of Specialty Gas Changeover Systems

Gas delivery functionality directly correlates to production ability and product quality at refineries. Companies need to choose a gas delivery system that can provide a continuous supply of specialty gas under specified conditions—the changeover system makes this possible.

There are two ways the specialty gas changeover system can function. This is accomplished through the use of either: 

1. Auto changeover manifolds
2. Manual changeover manifolds

Each of these types has its own unique advantages. Let's discuss these benefits in detail and explore the solutions that Swagelok offers.

Types of Specialty Gas Changeover Systems 

A changeover system facilitates an uninterrupted supply of gas to the production facility. It does so by drawing from a secondary source once the pressure at the primary source depletes. The system can be manual, semi-automated, or automated. When choosing from a semi or fully-automated system, it's important to know the difference between the two types of specialty gas changeover systems.

Auto Changeover Manifolds

Auto changeover manifolds facilitate switching between cylinders without incurring any downtime. The system offers two-stage pressure reduction to ensure uniform pressure at the outlet. The semi-automated manifold switches once it detects the pressure difference, but switching back needs to be done manually. The automatic manifold can perform the back-and-forth switching electronically without requiring any manual intervention. The advantage of this semi or auto changeover mechanism is that, by setting the changeover point at a lower pressure, the maximum amount of gas can be used leaving very little waste in the cylinder.

It is important to understand the role of the specialty gas source in the installation of the changeover manifolds. There are several factors to consider for the efficient installation and operation of the changeover manifolds. These include:

• Pressure and temperature at the gas source
• Type of specialty gas: Some gas may be toxic and corrosive in nature
• Material of the manifold and adjacent piping system: Routine monitoring of wall thickness is necessary to examine corrosion/erosion
• Gas flow rate
• Operational hours

Manual Changeover Manifolds 

Manual changeover manifolds are relatively low-cost to start with but may be less productive compared to auto changeover manifolds. These manifolds can be differentiated into two types—single and duplex cylinder manifolds.

Single-cylinder manifold: The single-cylinder system requires the operator to manually shut off the manifold once the bottle empties. It is then refilled or replaced with a new one. The operation remains completely shut until the replacement is complete, causing a loss of productivity.

Multi-cylinder manifold: Multi-cylinder changeover manifolds can be used when there is more than one bottle used in the process. As the primary cylinder gets exhausted, the operator can shut off the primary valve and refill the bottle while the backup source provides a continuous supply of gas.  

Swagelok Offers High-Quality Changeover System Options

Whether your operation requires manual or automatic changeover manifolds to supply critical specialty gas, Swagelok can help you select, design, and assemble the system as per your requirements. Our solution, the Swagelok Changeover (SCO), allows you to set the changeover pressure to your specification. When set to a lower pressure, SCO offers the benefit of waste reduction and cost efficiency. You can also make a selection of our products like the specialty gas changeover regulator which can assist in making the automatic switch between the specialty gas sources to counter the issues of downtime associated with the use of manual changeover manifolds.

As a local fluid system expert for your Northern California facility, you can rely on us to analyze your new or existing process conditions and help install a standardized or custom plan for the optimal operation of your gas distribution system. With a recommendation for high-quality components, customized design plans, and expertise, Swagelok is here to ensure that your refinery operates seamlessly. 

To find out more about how Swagelok Northern California can help you in the design and installation of specialty gas changeover systems, contact our team today by calling 510-933-6200.

About Morgan Zealear | Product Engineer, Assembly Services

Morgan holds a Bachelor of Science in Mechanical Engineering from University of California at Santa Barbara. He is certified in Section IX, Grab Sample Panel Configuration and Mechanical Efficiency Program Specification (API 682), and he is well versed in B31.3 Process Piping Code. Before joining Swagelok Northern, he was a manufacturing engineer at Sierra Instruments, primarily focused on capillary thermal meters for the semiconductor industry (ASML).