Low Separation Force Quick Disconnect Device

mechanical and fluid systems
Low Separation Force Quick Disconnect Device (KSC-TOPS-84)
A Self-Aligning, Self-Healing System for Pneumatics and Cryogenics
Overview
Innovators at the NASA Kennedy Space Center (KSC) have developed the Low Separation Force Quick Disconnect device for transporting pneumatic and cryogenic fluids. Umbilical systems employ fluid connectors known as quick disconnects to transfer fluids into a vehicle. Traditional quick disconnect systems have a separation force directly proportional to the line pressure. For systems with a high line pressure, large separation forces are generated when disconnecting the flow line which requires the use of large, heavy support structures. KSC's Low Separation Force Quick Disconnect device eliminates this need for heavy support structures by ensuring low separation force regardless of line pressure, which is advantageous for systems requiring high line pressure. Applications include any mechanism in which fluid is being transferred from ground to a vehicle or another system, especially where a high line pressure is used. Any companies that deal with fluid connectors, particularly in the aerospace sector, may find value in the invention.

The Technology
The Low Separation Force Quick Disconnect device uses an innovative seal arrangement and flow path to eliminate separation force from line pressure. A radial design ensures a low separation force regardless of line pressure. Ten holes around the internal seal cancel loads due to balanced pressure; thus, the central force exerted on the device is due to the springs fixed internally. The device also provides for additional optional characteristics including a self-aligning feature from a compliant mount and a self-sealing mechanism that keeps dust out of the device. The Low Separation Force Quick Disconnect device is designed to transport pneumatics and cryogenic fluid. Due to the low separation force and overall design, the system requires less heavy and high-strength support structures than conventional designs; the design permits lighter retention systems and reduces deflection variations. Aerospace specific uses of the invention include flight-to-ground, flight-to-flight and surface-system applications. Other uses of the invention include any mechanism in which fluid is being transferred from ground to a vehicle or another system, especially where a high line pressure is used.
This rendering illustrates how the Low Separation Force Quick Disconnect device enables easy line mating. The device re-routes fluid to flow into the connected line perpendicular to the typical flow path, and does so evenly around the circumference of the line for pressure balance. Thus, the disconnect pressure is no longer a function of line pressure (i.e., the only disconnect force is now supplied by the springs depicted in blue).
Benefits
  • Offers reduced separation force: Conventional quick disconnect designs apply separation force proportional to pressure, requiring high strength, heavy support structures and locking devices. The Low Separation Force Quick Disconnect device reduces the force required for successful umbilical separations at high line pressures.
  • Enables reduced support structure weight: Reduced separation forces allows for support structures like umbilical plates and locking devices to be lower weight and lower strength, reducing system mass.
  • Supports decreased contamination: The self-healing and self-cleaning mechanisms prevent contamination from dirt, dust, and other undesirable particles.

Applications
  • Aerospace and Aviation
  • Marine
  • Oil and Gas
  • Satellites
  • Unmanned Vehicles
Technology Details

mechanical and fluid systems
KSC-TOPS-84
KSC-14268
"Multi-User Spaceport Umbilical Low Force Disconnect," Tamasy, Gabor J. and Mueller, Robert P., January 12, 2021,
https://ntrs.nasa.gov/citations/20210010653
Similar Results
Astronauts on Planet Surface
Quick Disconnect for High Pressure Mate/De-Mate
Dusty, dirty environments can be very tough on connectors. The abrasive nature of dust and dirt particles can rub and wear down connector surfaces through friction, and have a negative effect on coatings used on gaskets to seal equipment. Dust on umbilical connections can also make mating and de-mating electrical and fluid connections difficult, hazardous, and unreliable. NASA's Quick Disconnect (QD) design uses the gas supplied by the umbilical to spray the connector surfaces prior to mating to remove dust and debris. The QD uses a novel dual-poppet design and springs that balance forces on umbilical components. This allows a controlled release of gas to clear away dust from the end of the connector before it it inserted in the supply umbilical. The connector assembly is capable of mating and de-mating under 3500 psi fluid/gas. One poppet seals the QD while de-mated and automatically cleans the front surface of the QD during mating. A second poppet seals the QD while de-mated and automatically cleans the cylindrical surface of the QD during mating. The internal cavity of the QD is specifically designed such that the pressure in the line is reduced from 3500 psi to 450 psi while surface cleaning occurs. Finally, all exterior connector surfaces are designed to minimize the entrapment of dust while in the de-mated position.
Astronauts on Planet Surface
Dust Tolerant Quick Disconnect With Self-Sealing Barrier
Dusty, dirty environments can be very tough on connectors. The abrasive nature of dust and dirt particles can rub and wear down connector surfaces through friction, and have a negative effect on coatings used on gaskets to seal equipment. Dust on umbilical connections can also make mating and de-mating electrical and fluid connections difficult, hazardous, and unreliable. NASA's Quick Disconnect (QD) design consists of columnar arrays of parallel filaments. All the pins of the electrical connector easily penetrate the barriers when the umbilicals are brought together. They are wiped clean of dust when they penetrate the barrier and mate cleanly and reliably. Likewise, the male end of a fluid connector penetrates the filament arrays of both connector ends. Since the filament arrays are oriented perpendicular to each other, the entire circumference of the connector is contacted by the filaments that stretch around, conform to, and sweep off dust from the mating surface ensuring a clean and secure connection.
front
Cryogenic Hydraulically Actuated Isolation Valve
NASA's cryogenic isolation valve technology uses solenoid valves powered by direct current (DC) electrical energy to control and redirect the energy stored in the upstream line pressure. Powering the solenoid valves only requires a DC power source capable of supplying 22 watts that can be distributed and controlled in an on/off manner. By achieving actuation using only upstream line pressure and a 22-watt DC power source, many additional support systems that are required for electromechanical and pneumatic actuation are eliminated. This reduction of parts results in several benefits, including reduced footprint, weight, and potential cost of the valve in addition to lower energy consumption. NASA fabricated several operational prototype valves using this technology for a rocket company. The table below shows the results of tests performed on these valves under cryogenic conditions. Please contact the NASA MSFC Technology Transfer Office for additional information.
Harsh Environment Protective Housings
Harsh Environment Protective Housings
These connectors are designed to be used in harsh environments and to withstand rough handling, such as being stepped on or rolled over by wheelbarrows or light vehicles. If the demated connectors are dropped or placed on the ground, the end caps will shield them from damage and contaminants. When mated, the seal between the housings and end caps keeps contaminants out. The end caps are latched to the housings so that the caps cannot be unintentionally opened; this latch can be opened only by depressing the levers. The spring used to open or close the cap is constructed of a shape memory alloy, allowing the cap to be opened and closed an almost infinite number of times. The cap actuation levers are designed so that only a 3/4-inch pull is needed to open the cap a full 190 degrees. The housings can accept most commercial-off-the-shelf electrical or fluid connectors (including those designed for cryogenics), thus eliminating the need for specialized connectors in hostile environments. The housings can also be grounded and scaled up or down to accommodate connectors of different sizes. The housings can be constructed of steel, aluminum, composites, or even plastic, depending on the environment in which they will be used and material cost constraints.
Corkscrew Filter Extracts Liquid From Air Charge
In the event of a fire aboard the Orion Spacecraft, the Portable Fire Extinguisher (PFE) can introduce up to three pounds of water into the cabin to extinguish a fire. A filter was needed to work in conjunction with the Orion Fire Safety System (OFSS) to filter water out of the cabin atmosphere after dispersal from the PFE. Airflow introduced to the smoke filter of the OFSS must be dry and free of large particulates for the sorbent material to effectively extract smoke generated by a fire. These moisture and particulate concerns prompted a re-design of the original filter, especially a filter that could be tested in Earth’s gravity and yielding results that would transfer to a microgravity environment. The newly designed filter uses a multi-phase flow separation method that allows the airflow to develop fully in a helical flow path. This flow path resides within a wicking material used to separate the liquid from the gas (air) while also trapping particulate matter. Helical flow paths implemented in the filter impart a centrifugal force upon the incoming gas/liquid mixture that develops an asymmetric liquid film on the inner contour of the helix. Upon active airflow, the larger water droplets are inertially forced into the inner contour flow path wall. The flow path walls are made from a wicking material, and all liquid film and liquid droplets that are inertially deposited onto the walls are adsorbed into the filter material. The resulting output flow from the filter is 100% gas. The Corkscrew Filter has a technology readiness level (TRL) of 5 (component and/or breadboard validation in relevant environment) and is now available for patent licensing. Please note that NASA does not manufacture products itself for commercial sale.
Stay up to date, follow NASA's Technology Transfer Program on:
facebook twitter linkedin youtube
Facebook Logo Twitter Logo Linkedin Logo Youtube Logo