Design of Waste Gas Vent Valves for International Space Station

A unique family of valves was developed for venting waste gasses to space vacuum. The valves are part of the Japanese Experimental Module (JEM) Integrated Waste Gas System (IWGS) of the International Space Station (ISS).

The design features of the valves include chemical compatibility with waste gasses, pneumatic and manual actuation, electrical and visual position indication, and exceptional leakage control. The valves are designed as Orbital Replacement Units (ORU’s) with provisions for Extra Vehicular Activity (EVA) handling.

This paper provides an overview of the system requirements and the principles in valve design which satisfy those requirements.