Metal bellows, capable of suppling required spring rate and operational stability, replaced diaphragms, sliding seals, and springs in design of small gas regulator

Wang, W. S.

Wright, H. W., Jr.

English

NASA Technical Reports Server

May. 1972
	 B72-10211 
NASA TECH BRIEF 
Ames Research Center 	 4r 
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 program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Miniature High Pressure Regulator 
The problem: 
To design a small gas regulator capable of supply-
ing 15-100 psig gas pressure from a source at 3000 to 
400() psig, i.e., a gas pressure of 205-791 kN/m 2
 from 
a source at 20.8 to 27.7 MN/M2. 
Outlet et
 
Compensation	 F^i 	 Cap Plate	 \, Seat	 Guide ,, 100 psi 
Atmosphere 
Bellows 
Vent
Expansion Joint 
(Tank Pressure 
Seat :-embly
Filter	 Inlet 
The solution: 
Utilize metal bellows in place of bulky diaphragms, 
sliding seals, and springs generally employed in 
regulators. 
How it's done: 
The differential area of the concentric bellows 
shown in the diagram is exposed to the downstream 
pressure. Initially, gas supplied to the inlet flows 
through the open poppet and increases the pressure 
in the downstream volume until it reaches the regula-
tion pressure which is of sufficient force to close the
poppet and shut off the high-pressure gas. Variations 
in supply pressure are accommodated by an expansion 
joint which retracts and enlarges the poppet area 
progressively so that the pressure drop across the 
seat is reduced for a given poppet position, thus 
maintaining constant flow. The pressure compensator 
plate moves so as to maintain a constant differential 
pressure between ambient and the downstream 
volume. 
The small size of the regulator permits the use of 
bellows with a stiffness adequate for supplying the 
required spring rate without recourse to additional 
springs. Since all bellows are exposed only to down-
stream pressures, distortion of the effective area of 
bellows seals by high pressure is avoided. Stability 
of operation is assured by appropriately-sized flow 
passages through the bellows' upper plates. Sudden 
changes in flow demand, created by either opening 
or closing downstream solenoids, result in a transient 
pressure differential across the plates which aids the 
movement of the poppet as required. This action re-
sults in faster response and, consequently, lower lock-
up pressures. 
The only metal-to-metal contact in the regulator is 
the bellows plate and the poppet seat. The poppet 
seat is a soft metal stop which prevents the extrusion 
of the elastomeric poppet seal under the initial high 
differential pressure. 
Note: 
No additional documentation is available. Specific 
questions, however, may
 be directed to: 
Technology Utilization Officer 
Ames Research Center 
Moffett Field, California 94085 
Reference: B72-10211
(continued overleaf) 
This document was prepared under the sponsorship of the National	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the united States	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19720000211 2020-03-17T03:33:44+00:00Z
Patent status: 
No patent action is contemplated by NASA. 
Source: Harvey Weston Wright, Jr. and

William Shu-Shin Wang of

TRW Systems Group, TRW Inc.

under contract to
Ames Research Center 
(ARC-10428) 
B72-10211	 Category 07


Miniature high pressure regulator

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