High performance miniature flightweight pilot operated valves

Abstract

Current emphasis on Theater Missile Defense (TMD) has resulted in the production of very high performance miniature pilot operated valves at Kaiser Marquardt (KM). Valves currently in production are for on/& as well as pulse modulated flow control of high pressure gases (2000-10000 psi) and several rocket propellants (2600 psi). Flow rates range up to 0.75 Ibs/sec of gas or 1.25 lbslsec of water, yet the weight is less than 0.2 Ibs per valve and the valve size is similarly miniature. Response characteristics are equally spectacular ranging from 13 milliseconds. The design concept and the performance characteristics of three valve versions which were recently produced are presented in this paper. Reference 1 describes some of KM’s activities with Micro Propulsion Systems. Valves currently of interest have higher flow requirements than those described in Reference 1. Flow capabilities featured in the three valves described In this paper range up to 1.25 Ibs/sec of water and up to 0.75 Ibs/sec of gas. These were met with two stage, so called pilot operated valves originally developed at KM on IR&D projects and reported in Reference 2. in recent years the requirements for insensitive munitions (MILSTD-2105) have made the use of gelled propellants, very attractive. Kaiser Marquardt has previously addressed gelled propellants (Reference 3) and this experience was applied in the design of the propellant valves described herein. INTRODUCTION PILOT OPERATED VALVE DESIGN Theater Missile Defense Requirements demand miniature, extremely fast valves for control of rocket engines, pressurization systems, and gas cooling systems. These valves are operated in a pulse modulated mode to achieve flow control or simply as shut-off valves. Applicable flow media include: inhibRed fuming nitric acid (IRFNA), nitrogen tetroxide (NTO), and amine fuels in either liquid or gel form for rocket propellants. Gases of interest are: helium, nitrogen and argon. Propulsion System Optimizations for TMD have shown desirable operating pressures to be well over 1000 psi with gas storage pressures up to approximately 10,000 psi. These and higher pressure ranges have been addressed on past technology programs and d All three of the valves described in this paper employ the s h e design concept. This concept is shown in Figure 1. FIGURE 1 PILOT OPERATED VALVE DESIGN m m