How are valve plates created so perfectly you may ask? The magic of laser cutting and a chosen type of gas. Learn all about the details below.
The laser cutting process is used in creating metal valve plates that are one of the most important components in a compressor. This process uses assist gas including oxygen, nitrogen, and air, in ensuring that heat is transferred efficiently.
In the laser cutting process, there is a need to choose between a gas that will offer a cost-effective solution and another that will provide a higher-quality cutting.
But first, you need a good idea of what each of these entails, and how laser cutting creates metal valve plates.
This and many more have been outlined below.
What is a Valve Plate?
A valve plate is an important component in the valve assembly, and it serves as a seal between different parts of a compressor.
A valve plate needs to be durable, strong, and resistant to heat, corrosion, and pressure since it will undergo stress each time the compressor is used. There are metallic and thermoplastic valve plates and either of these can be created through the process of laser cutting.
How Laser Cutting Creates Metal Valve Plates
Fiber or CO2 lasers employ a light beam to cut metallic materials including valve plates.
However, this metal cutting process is also carried out using an assist gas. Some of the most popular types of assist gases are oxygen and nitrogen.
Air, on the other hand, has proven to be a cost-effective alternative to either of these gases.
In the laser cutting operation, an assist gas (oxygen, nitrogen, or air) is injected at the nozzle to supplement the process. This initiates an exothermic reaction where energy is released by light or heat.
As a result, the introduction of assist gas during the laser cutting process helps in the effective transfer of heat. This is compared to when a light beam alone is used.
Let’s take a look at each of these gases and how they help in creating metal valve plates in laser cutting operations.
Oxygen:
Oxygen was once the most popular gas when it comes to laser-cutting operations. It is a standard active assist gas employed in the laser cutting of mild and carbon steels.
Also, oxygen is often referred to as cutting gas, and a material that is to be cut is burned and vaporized after being heated.
Nitrogen:
Nitrogen is an inert gas, and it is also widely used in laser cutting. This gas is employed in laser-cutting metal valve plates where aesthetics appeal and edge quality are required in designs.
The reason can be tied to the fact that nitrogen gas provides a cleaner cut edge compared to oxygen and air.
Air:
Air is made up of 80% nitrogen and a greater part of the remaining percentage, made of oxygen.
Air-assist cutting has been used since 1998 to laser-cut metals. It offers cost-saving benefits over the use of oxygen and nitrogen gas. The reason is, air consists of a high concentration of nitrogen which enables it to cut metal valve plates.
However, the mere fact that it is a combination of various gases means it is a diluted version of either of these. The level of precision is not the same compared to the designs offered by nitrogen-assist gas.
Benefits of Air Laser Cutting
Air-assist cutting of metals such as valve plates comes with several benefit, which includes:
1. Quality Cuts:
When compressed air was used on CO2 lasers years ago, mode quality was a major limitation; however, there have been major improvements since then.
As such, air-assist cutting has become a popular method of cutting a range of materials including aluminum and stainless steel.
Moreover, the high heat of fiber lasers, coupled with injected air helps in creating cuts without oxide being formed on the cut’s surface. Since oxide is not formed, it reduces or takes away the need for secondary cleanup operations.
Air may have been used to cut thin material, but it can still be used to cut a good number of stainless parts.
2. Cost-saving Alternative:
There is an abundance of air in the atmosphere and as such, the air is readily available to be used as an assist gas. Air is also less expensive than nitrogen and oxygen, which is why companies looking to cut costs while creating metal valve parts resort to air.
On the other hand, 90% of the total costs of operations can be tied to the cost of nitrogen. The latter is evidence that oxygen is a cost-effective alternative to the use of nitrogen.
Consequently, air offers a huge return on investment especially when fiber lasers are used or stainless steel is cut.
3. Increased Throughput:
The use of air in laser cutting metal valve plates results in faster cutting and increased throughput.
For instance, several cutting tests that were carried out on a range of materials and thicknesses revealed that:
- Material thicker than 10 gauge, nitrogen cuts faster. But, in a mild steel range of 10 gauge, air cuts 3% faster than nitrogen.
- In the aluminum range from 0.190 in. down to 0.032 in., the air is nearly 14% faster than nitrogen.
- In the stainless steel range from 0.750 in. down to 0.036 in., the air is about 22% faster.
The Benefit of Nitrogen-assist Gas in Laser Cutting
The most evident advantage of using nitrogen in laser cutting is that it offers higher quality cuts. Compared to air-assist gas, it does a better job since materials that are cut with the aid of this gas do not have blemishes.
Choice of Nitrogen or Air in Laser Cutting of Metal Valve Plates
In deciding whether to use nitrogen or air in laser cutting, a choice of which is dependent on what you prioritize more.
Do you want cleaner cuts that will take away the need for secondary descaling operations? Or do you want to save costs in the long run?
At this juncture, you already know that nitrogen will offer better edge cuttings than air, whereas the latter is more cost-effective.
Conclusion
Light beam and assist gases like oxygen, nitrogen, and air have proven useful in laser cutting metals. This includes stainless steel and aluminum.
Air-assist cutting, on the other hand, offers cost-savings since it is less expensive compared to nitrogen and oxygen. Several tests have also shown that air cuts faster, which can bring about enhanced productivity.
Nonetheless, if it is critical for your metallic valve plates to have the perfect aesthetics and edge cutting, nitrogen is the assist gas to use in your laser-cutting process.
