Ball valve design incorporates modular construction in easy-to-install, easy-to-replace cartridge housing, and a system of cams to lift upstream and downstream seals away from the ball during rotation. Tests conducted on nitrogen tetroxide prove new valve to be more efficient than previous models in preventing leakage

Carriker, J. W.

Fieweger, R.

English

NASA Technical Reports Server

Convoluted 
Bellows
Shaft Upstream Seal 
Downstream 
Seal
December 1970	 Brief 70-10653 
NASA TECH BRIEF 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage commercial 
application. Tech Briefs are available on a subscription basis from the National Technical Information Service, Springfield, 
Virginia 22151. Requests for individual copies or questions relating to the Tech Brief progam may be directed to the Tech-
nology Utilization Division, NASA, Code UT, Washington, D.C. 20546. 
Long Life, Low Cost Ball Valve, with Lifted Seals

and Cartridge Type Construction 
0
A new ball valve design incorporates a modular 
construction in an easy-to-install, easy-to-replace 
cartridge housing, and a system of cams to lift the 
upstream and downstream seals away from the ball 
Key 
Shaft	 Cam 
Cam Follower
	
	 Guide Pin 
Section G - G 
Spring	 Cam ..	 Cam Follower Lifter 
(20 Places)
	
Ring 
Flexible 
V Torus 
Flow 
Cartridge 
Housing 
Longitudinal Section of Cartridge 
during ball rotation. The concept provides longer valve 
life and improved seal performance through less wear 
on the seals, and less expensive maintenance through 
easier replacement of the entire assembly. In tests 
conducted on N204, the new valve proved to be more 
than 200 times more efficient than previous models 
in preventing leakage.
The ball section of the assembly is integral with 
an axial shaft and has a central hole which, is normal 
to the shaft. When this hole is in alignment with the 
two opposing holes in the cartridge housing (see fig.), 
the valve is open. Inside and around the downstream 
opening in the housing is a short, convoluted, metallic 
bellows for absorbing outward movement of the down-
stream seal. A flexible torus serves the same purpose 
at the upstream end: to seal between the upstream seal 
and the housing while permitting outward movement 
of the seal. 
Between the open and closed positions of the valve, 
the ball rotates 90 degrees. At the beginning of the 
"open" rotation, the ball seals are lifted away from the 
ball by cams on the ball shaft. The cams operate 
through a system of cam followers, guide pins, and 
lifting rings surrounding the ball. During the closure 
rotation, these seals are not moved; i.e., ball-to-seal 
contact is maintained. When the valve is closed, the 
ball seals are pressed against the ball by springs and by 
operational pressure exerted on their exposed areas. 
An Oldham-type coupling connects the ball shaft 
to the valve operating mechanism. This coupling en-
gages keyways in the ball shaft and the operating shaft, 
permitting considerable nonalignment between the 
two. Thus the cartridge can be easily installed in the 
valve body without disturbing the assembly or adjust-
ing the operating mechanism. 
For high-pressure systems, the torus-bellows system 
described is recommended. For low-pressure applica-
tions, however, the torus and bellows can be omitted, 
and the ball seals can be replaced with one-piece flex-
ible lip seals. This design costs less to fabricate and is 
easier to clean. 
(continued overleaf) 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19700000633 2020-03-17T01:00:49+00:00Z
Note: 
Requests for further information may be directed 
to
Technology Utilization Officer 
Manned Spacecraft Center, Code BM7 
Houston, Texas 77058 
Reference: TSP70-10653
Patent status: 
No patent action is contemplated by NASA. 
Source: J. W. Carriker and R. Fieweger of 
Aerojet-General Corp. 
under contract to 
Manned Spacecraft Center 
(M SC- 13430)
ft 
Brief 70-10653	 Category 07


Long life, low cost ball valve, with lifted seals and cartridge type construction

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