The OmniSeal spring-energized explosion-proof seal of Saint-Gobain Seals has been recognized as a static seal in the rocket engine check valve of the aerospace industry.
A check valve is a flow control device that only allows pressurized fluid (liquid or gas) to flow in one direction. In normal operation, the check valve is in the closed position where the seal is secured by static seals designed to withstand any blowout. Once the fluid pressure reaches or exceeds the rated threshold pressure, the valve opens and allows fluid to transfer from the high pressure side to the low pressure side. A pressure drop below the threshold pressure will cause the valve to return to its closed position. Check valves are also common in the oil and gas industry, as well as in pumps, chemical processing, and fluid transfer applications.
In most cases, design engineers integrate check valves into their rocket engine designs. Therefore, the role of seals in these valleys is very critical in the entire launch mission. A blow-out prevention seal is used in the check valve to keep the pressurized fluid on the high-pressure side while preventing the seal from spraying out of the housing. Under high pressures and rapid changes in sealing surface pressure, keeping the seal in its housing is very challenging. Once the dynamic sealing surface of the hardware is separated from the sealing lip, the seal may be blown away from the housing due to the residual pressure around the seal. Usually seat seals, simple Teflon blocks, are used for check valves, but the performance of these seals is inconsistent. Over time, the seat seals will be permanently deformed, causing leakage.
Saint-Gobain Seals’ explosion-proof seals are derived from its OmniSeal 103A configuration and consist of a polymer jacket with a spring energizer. The sheath is made of a proprietary Fluoroloy material, while the spring can be made of materials such as stainless steel and Elgiloy®. According to the working conditions of the check valve, the spring can be heat treated and cleaned by a special process. The picture on the left shows an example of anti-blowout seals for general Saint-Gobain seals in rod seal applications (note: this picture is different from the seals used in actual check valve applications, which are custom-designed). Check valve applications The seals in can work in a low temperature range up to 575°F (302°C) and can withstand pressures up to 6,000 psi (414 bar).
The OmniSeal explosion-proof seal used in rocket engine check valves is used to seal pressurized gas and liquefied gas in the temperature range below -300°F (-184°C) to 122°F (50°C). The seal can withstand pressures close to 3,000 psi (207 bar). Fluoroloy® sheath material has excellent wear resistance, deformation resistance, low friction coefficient and extreme cold temperature capability. OmniSeal® Blowout Prevention Seals are designed to run hundreds of cycles without any leakage.
The OmniSeal® product line offers a variety of designs, such as 103A, APS, Spring Ring II, 400A, RP II and RACO™ 1100A, as well as a variety of custom designs. These designs include sealing sleeves of various fluorine alloy materials and springs of various configurations. Saint-Gobain Seals’ sealing solutions have been used in launch vehicles such as the Atlas V rocket engine (to send the Curiosity Mars rover into space), the Delta IV heavy rocket and the Falcon 9 rocket. Their solutions are also used in other industries (oil and gas, automobiles, life sciences, electronics and industry) and environmentally friendly industrial dyeing process equipment, chemical injection pumps, the world’s first subsea gas compression station and chemical analyzers, etc. application.
Post time: Nov-08-2021
