A highly reliable Ultra Clean Diaphragm Valve (UCV) made byHAM-LET, a global manufacturer of instrumentation valves and fittings for industrial and high purity applications, is being used in a satellite propulsion system produced by OHB Sweden.
The SGEO stationary satellite propulsion system uses electric power to expel the Xenon at a very high velocity in order to generate thrust. Earlier versions of the system used pyro technique valves which were fired before the satellite was launched. OHB Sweden decided to upgrade to HAM-LET's UCV diaphragm valve due to its extremely clean operation and high reliability.
High-pressure high-flow models from HAM-LET’s Ultra-Clean Valve Series are made to UHP (Ultra High Purity) specifications. These models come with end connections in two alternative sizes, 1/4” and 1/2” as standard. With their compact design, these valves can comfortably perform in high-pressure, high-flow applications including their use as shut-off valves at pressures up to 21 MPa (3,060 psi). They are supplied with a large choice of fluid-specific seat materials to meet all needs.
HAM-LET's UCV diaphragm valve is placed at the Xenon tank inlet to separate the tank from other high pressure tube sections. This prevents the pressure tanks from undergoing multiple pressure cycles during the integration process.
For safety reasons, multiple ground tests are done on the propulsion system while it is being built. This is done to ensure that all components are well integrated and can survive the vibrations generated during launch and spacecraft separation process.
All safety design processes begin on a component level. Each component has to be able to withstand predicted stress levels in order to ensure system integrity and function when the spacecraft has reached its orbit.
Once in orbit, many other factors such as radiation, extreme temperatures and aging have an impact on the system’s performance. However, most of these stresses have impacts on electronic components rather than on the fluids being used.
During the qualification process to be accepted as part of the SGEO space propulsion system, HAM-LET UCV valves were tested for operational cleanliness, resistance to shock, vibration and rapid temperature changes. OHB and HAM-LET also conducted flow tests, assessing the impact of a long term exposure to Xenon on the valves. OHB Sweden also conducted normal pressure and leakage assessments, where HAM-LET's valve must withstand pressures up to at least 279 bars for five minutes, without leaking or showing evidence of any deformation.
Successful completion of all these tests awarded HAM-LET UCV valves the approval and acceptance to be mounted on OHB Sweden's satellite propulsion system.