Quick-disconnect coupling is used for uncoupling of plumbing during ground-to-vehicle transfer of cryogenic and hazardous fluids. The coupling allows remote positive control of liquid pressure and flow during the transfer operation, remote connection and separation capabilities, and negligible liquid spillage upon disconnection

De Witt, R. L.

Schmidt, H. W.

English

NASA Technical Reports Server

June 1965	 Brief 65-10202 
NASA TECH BRIEF 
NASA Tech Briefs are issued by the Technology Utilization Division to summarize specific 
technical innovations derived from the space program. Copies are available to the public from 
the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia, 22151. 
Quick-Disconnect Coupling Provides Safe Transfer of Hazardous Fluids 
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The problem: To develop a device which allows 
quick and safe uncoupling of plumbing during 
ground-to-vehicle transfer of cryogenic fluids and 
hazardous fluids such as fluorine. 
The solution: Use a "quick-disconnect" coupling 
which allows remote positive control of liquid pressure 
and flow during the transfer operation, remote con-
nection and separation capabilities, and negligible 
liquid spillage upon disconnection.
How it's done: To commence the connection 
phase, a rear" ard movement of the driver (A) relative 
to the ground-half housing (B) spreads the locking 
fingers (C). Both halves of the coupling are then 
aligned and mated. Finally, a forward movement of 
the driver arrangement closes the fingers around the 
vehicle-half housing (D). To continue positive contact 
between the halves, it is necessary to maintain the 
driver in this forward position.
(coot mood (is orbit 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States Govern-
ment, nor NASA, nor any person acting on behalf of NASA: A. Makes 
any warranty or representation, express or implied, with respect to the 
accuracy, completeness, or usefulness of the information contained in
this document, or that the use of any information, apparatus, method, 
or process disclosed in this document may not infringe privately-owned 
rights; or B. Assumes any liabilities with respect to the use of, or for 
damages resulting from the use of, any information, apparatus, method, 
or process disclosed in this document.
https://ntrs.nasa.gov/search.jsp?R=19650000200 2020-03-11T17:23:58+00:00Z
The coupling valving is opened by introducing pres-
surized gas into the chamber (E) of the ground half. 
The force developed moves the concentric slider ring 
(F) downstream and raises the ground-half trim (G) 
from its seat (H). As the ground-half trim continues 
its movement, it bears against the trim (I) of the 
vehicle half of the coupling and forces it from its seat 
(J). Both the ground-half loading spring (K) and the 
vehicle-half loading spring (L) are compressed by the 
operation, which gives assurance of a positive shut-
down in case of a pressurizing gas failure. 
During liquid-fluorine transfer through the cou-
pling, external leakage is prevented by a combination 
of the static labyrinth grip (formed by the intermesh-
ing faces (M) of the two halves) and the inner and 
outer V-ring seals (N and P). Any cryogenic liquid 
leakage past the inner seal is allowed to gasify in the 
cavity between the labyrinth faces and the outer V-
ring seal. Because of the orientation of the V-ring 
seals, any pressure buildup in the cavity could not 
exceed that of the liquid-fluorine transfer pressure 
within the flow passage (Q). An excess of the cavity 
pressure over the transfer pressure would cause leak-
age in a reverse direction (e.g., back into the fluorine 
flow passage). The coupling valving is closed by vent-
ing the chamber of the ground half and allowing the 
loading springs in both halves to seal their respective 
trims. Separation of the two halves of the coupling 
is accomplished by a rearward movement of the driver
to spread the locking lingers and a final rearward 
movement of the entire ground half. 
Notes: 
This coupling could be used in plumbing systems 
for the transfer of any cryogenic or hazardous 
fluids such as rocket propellants, and in low pres-
sure (150 psig) gas transfer operations. It can also 
be used as an "in-line" pressure and now control 
valve. 
2. Inquiries concerning this invention may be directed 
to:
Technology Utilization Officer 
Lewis Research Center 
21000 Brookpark Road 
Cleveland, Ohio, 44135 
Reference: B65-10202 
Patent status: NASA encourages the commercial 
use of this invention. It has been patented by NASA 
(U.S. Patent No. 3,170,486), and royalty-free license 
rights will be granted for its commercial development. 
Inquiries about obtaining a license should be ad-
dressed to NASA, Code AGP, Washington, D.C., 
20546. 
Source: Richard L. Dewitt and Harold W. Schmidt 
(Lewis-125) 
Brief 65-10202	 Category No. 01


Quick-disconnect coupling safe transfer of hazardous fluids

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