Image Automatic Pressure/Vacuum Relief Cap for Fuel Tank Markets Petroleum Cargo Tanks Jump to Section Product Options Related Products Product Options Part Number Size Male Thread Material 200-PV-9 2" NPT Aluminum 2000L 2" NPT Zinc 2500L 2-1/2" NPT Zinc Related Products Image Standard Vent Cap for Stationary Fuel Tank Image Vacuum Relief Valve Female Outlet Image Vacuum Relief Valve