Understand the Gas Characteristics to Design the Right Gas Cabinet
Designing gas cabinets to hold cylinders is an effective way of employing a centralized gas delivery system for workers and ensuring an easier way to change out spent cylinders without hampering production. When considering adding, repairing or improving a gas cabinet, manufacturers need to keep in mind the special characteristics of each type of gas that can impact the materials and operation of the gas cabinet. Some gases, such as cryptogenic gases, are extremely cold and can cause components to become brittle. Other gases can become flammable when exposed to changing temperatures and pressure, causing a fire in the piping system, which can backflow into the gas cabinet.
Following are the characteristics of certain gases that a manufacturer may choose to use in a gas cabinet, as well as the types of gas delivery components that work best for these gases to ensure a safe operation.
Corrosive gases have the ability to deteriorate or destroy other materials on contact or when there is water present. These gases can also irritate and damage the skin, eyes, lungs or mucous membranes. If an OEM has a working environment where any inorganic materials or water may be able to penetrate the gas cabinet, then the gas delivery system should be equipped with traps and check valves to prevent water and other materials from getting sucked back into any cylinders containing corrosive gas. In addition, the manufacturer should have a safety policy in place that mandates workers to wear protective clothing and equipment when changing out the cylinders, as well as situate an eye and body wash station nearby.
Toxic and Poison Gases
These types of gases can come with a range of different characteristics. They can be non flammable, flammable, oxidizing, reactive and high pressure. Their toxic nature will be based on the specific gas. During the design of a gas cabinet utilizing one of these gases, one issue that needs to be addressed is potential leaking of toxic gas during change out of the cylinders. Any time there is the toxic gas lurking in the inline, it could potentially leak into the room when a worker opens the cylinder valve. Purge valve systems should be designed into the gas cabinet to remove toxic gas from the piping manifold. You can purge the lines using an inert gas.
Oxidant gases have the ability to combust, but won’t burn as a typical flammable gas. This type of gas can, except for O2 gas, displace the oxygen that is present in the room. Thus, manufacturers should keep all combustible materials away from the cylinders. A gas delivery system can be built fully enclosed with a small access panel where a person can reach inside to control the valves. Oxidant gases should be used with a regulator that is specifically designed and has a label that says it was cleaned for O2 gas service.
Cryogenic gases have temperatures that can reach a boiling point of -130 degrees Fahrenheit. This extreme coldness can significantly deteriorate many materials, making them brittle and increasing the possibility that they crack under high pressures. Blocks in the inline can also cause temperature fluctuation, and an increase of temperature can make the line burst from pressure buildup. A safety relief valve as well as a vent line should be considered when designing a gas cabinet for these gases.
Pyrophoric gases are commonly used in the semiconductor industry. These gases can spontaneously explode or catch fire without the presence of any materials to ignite them. Some pyrophoric gases can also release an abundance of heat energy. A manufacturer must take as many precautions with pyrophoric gases as they would with flammable gases when designing a gas cabinet for these gases. This includes a purge valve, vents, and a flash arrestor for the delivery system.
Axenics takes every precaution to ensure that a gas cabinet is built to specifications precise to the manufacturing operation, while making sure to use materials and components that are suitable to the characteristics of each gas. Contact our in-house engineers to discuss gas cabinet options and to decide on the type of gas that would be appropriate for your project or application.
If you’re considering working with a contract manufacturing company, it’s important to analyze a variety of factors before making a choice. Above all else, your choice should ultimately be about much more than the cost of the services. It should also be (and maybe even more so) about the value of the services being provided.
We understand cost matters. Everyone wants to get the best quality of products and services for the best possible price. However, there are times when quality takes precedence over price. When it comes to manufacturing, the quality of the products — from individual components to complex assemblies — really matters. If you’re looking for a contract manufacturing partner that values quality as much as you do, it’s worth paying the price.
When reviewing quotes from contract manufacturing providers, you may want to take the following into consideration before making a final choice:
1. What’s Included?
When reviewing a quote from a contract manufacturer, it’s important to understand what is included in the price. Are they just quoting you for materials and labor? If so, it’s possible that there will be some hidden costs that get added on, such as overhead fees for equipment and tooling, as well as any packaging or shipping that they might provide for you as well. Be sure to outline as specifically as possible what you want the company to do for you – beyond the manufacturing – so you can get a clear picture of the total cost. Otherwise, you may think they’re pricing is better than the competitor’s while the services aren’t comparable.
2. What’s Their Skill Level?
Don’t assume that all contract manufacturers provide the same level of skilled labor. It’s important to verify the expertise of the technicians that will be doing the work for you. It’s also important to verify what certifications and processes the company has in place to ensure the project is completed to specification, and on-time. Ask for copies of any applicable certifications, and take a look at online reviews, testimonials and information provided on their website, so you can confirm the expertise of the company you’re considering working with.
3. Do They Offer Quality Testing?
Some contract manufacturers may not clearly indicate whether they offer quality testing services along with – or as a part of – their fabrication services. This is a highly valuable service, because it ensures the quality of the components and/or assemblies produced matches industry standards, as well as any specific requirements your organization may have. If this service is included, it will be reflected in the price.
4. Is it a One-Time Project, or Ongoing?
If you have a contract manufacturer that you use for ongoing work, the price estimate you receive for additional projects may be lower than if you were to price out a new provider for a one-time project. Contract manufacturers often negotiate volume discounts from material suppliers, and will pass on some of that savings to you. If, however, they are being hired for a one-time gig, or one that requires uncommon materials, the estimate may be higher. It’s important to keep this in mind when shopping for a contract manufacturer.
Ask for a Bill of Materials
All of the above can be verified with a detailed bill of materials (BOM), which reputable contract manufacturers should always provide to you. The BOM should include specific information about what is included in the quote, and the factors affecting the total. This empowers you to make an educated decision about which contract manufacturer can best meet your quality needs, while also meeting your budget limitations.
Remember – the lowest quote is not always necessarily the best. Be sure to consider the contract manufacturing services being provided, the expertise of the company, the quality of products and services delivered, and the potential for long-term cost savings opportunities. The value of working with the right contract manufacturing company is often worth a slightly higher price tag.