612205001

This inlet cover is specifically made for the Walvoil SD6 valve series, so it should be a direct fit as long as you're working with that model.

Built into the inlet section, the relief mechanism works to keep pressure from climbing too high inside the system. When pressure hits a point where components could get stressed or damaged, the relief feature kicks in and regulates it back down. For a SD6 series Walvoil setup, having that protection right at the inlet is a solid way to safeguard downstream valves and other components without needing a separate relief valve added elsewhere.