By APM Hexseal 29
APM Hexseal's self-sealing nuts are designed to seal to 20,000 psi, as well as fasten where gas or liquids are present or under pressure (vacuum). APM's SEELNUT stainless steel self-sealing nuts feature an embedded (bonded) silicone insert technology that eliminates the need for liquid sealants. The insert features threads on the I.D. surface (an APM exclusive feature not available on competitive sealing-nuts) mating with the fastener's threads for 100% sealing and torque, which also permits 360° metal-to-metal contact between the fastener and equipment contact surface for positive sealing. Because no adhesive is required (dry), the fastener can easily be removed many times for field servicing and upon initial installation promotes more precise torque. There are no chemical vapors for workers to breathe in and no waste disposal problems.
For users who require additional vibration control, APM offers several embedded "dry" threadlocking techniques. SEELNUTs are a UL recognized component and easily operate in a temperature range of -160° to +500°F (-106°C to +260°C). High-pressure SEELNUTS are used extensively in underwater, surface marine, instrumentation, medical, military-ground, aviation, automotive, robotics, and off-road construction equipment in a wide variety of hydraulic, pneumatic, and electrical control systems.