How to Have 100% Leak Free Aeronautics in 2023
By Jim Scott, Senior Engineer at SECO SEALS
When it comes to gas and fluid connections for aviation, 37 degree flare tube fittings are a popular choice in the aerospace industry. These flare fittings are used to connect two pieces of tubing together. This type of standard connection is often used in systems that require high pressure and temperature. However, to ensure that these systems work 100% of the time, proper gasket selection is crucial. In this article, we will discuss the importance of proper gasket selection and installation in flare tube fittings.
A precision crush gasket is an essential component in flare tube fittings, as they help to seal the connection between the two pieces of tubing. SECO7 seals are made from thin metal. They are designed to withstand the high pressure and temperature of the system. SECO has supplied them to major aerospace companies like Boeing, Lockheed, NASA, Northrop and Raytheon, Bell Helicopter and Cessna. SECO SEALS is an approved source of supply on their company standard. SECO7 seals are made out of various metals, such as aluminum, copper, nickel, and stainless steel, and are available in nominal tube sizes ranging from one eighth inch to three inches.
To ensure that these SECO7 gaskets are of the highest quality, we manufacture them to in accordance with an ISO9001 and AS 9100 quality system. These gaskets are dead soft annealed. When the gasket is compressed down on the fitting, it becomes fully work hardened, which provides a secure seal. The initial compression causes the SECO7 seals to form to the fitting surface so it’s important to wait 15-20 seconds after installation and re-torque the connection.
Different types of gaskets are used for different types of fluids and gases. Copper gaskets are typically used for gases such as liquid oxygen, oxygen, water, methane, and some hydrocarbons. Nickel gaskets are used for hydrocarbon applications like kerosene, avgas, and gasoline. Stainless steel gaskets are used for corrosive applications like Skydrol and hydrazine. And aluminum gaskets are used for aluminum connections and fittings. In cases where mismatched metals are being used, we may recommend using a tin plating on the seal to prevent galvanic coupling.
Proper gasket selection is essential for ensuring that flare tube fittings work 100% of the time. SECO may be able to suggest some material options for your specific applications.
But there is more to the story, My family has been involved with space sealing technology for nearly 65 years. It all started with my father, Jim Scott Sr., who began working on the Atlas V rocket vehicle in 1958. At that time, the original rockets had crashed twice due to a problem with the liquid oxygen tanks leaking helium. My father was able to design a copper seal that went on the tanks, which was pressurized with helium, and this solution became a standard for all space programs from then on.
In 1969, my father started SECO SEALS, a company that specializes in creating soft metal gaskets for 37-degree flare tube fittings. These gaskets are used in a wide range of high-pressure applications, including jets, rockets, oil platforms, and more. The company was started out of our family home and garage.
As the business grew, I eventually took over and expanded the aerospace technology to a variety of different industries. We now use standard products, commercial off the shelf, to solve many day to day problems that occur when leaked harmful gases and liquids in the atmosphere. This not only provides a clean environment but also the safety of the system, whether it be a rocket, an airplane, a car, or HVAC breathing oxygen systems for deep sea diving, oil platforms, in all applications where they need 100% certainty on sealing.
My family’s experience in the space industry has given us a unique understanding of the importance of proper gasket selection in high-pressure systems. Our gaskets have been used in a wide range of applications, from aerospace to commercial, and have proven to be a reliable solution for leak-free systems. By using standard products, commercial off the shelf, we can provide a clean and safe environment for the users.
