Non-Return Valve

The Non Return Valve (NRV) is used to prevent the back flow and mixture of bi-propellant fuels in spacecraft propulsion systems.  Chemical propulsion systems need to show the flow of vapours from the propellant tanks to the helium pressurization system and between fuel and oxidiser tanks in a bi-propellant system.

During normal operation of the pressurisation system the valve opens at a predetermined cracking pressure to allow gaseous Helium (GHe) flow to pressurise the respective propellant tanks.  When the pressure differential across the valve in the normal flow direction reduces to a predetermined value the valve closes by the action of a preloaded spring thus preventing the reverse flow of gas or vapour when the pressure increases in the reverse flow direction.

Performance Characteristics

Status

The Nammo Space Non-Return Valve has flight heritage on the following platforms:

• EuroStar 3000
• SpaceBus 4000
• AlphaSat
• Veg Upper Stage AVUM