Toxic Gas Dampers HTG-230 A rectangular flanged damper provides up to 15 in. wg differential pressure; velocity up to 5000 fpm; and temperature range of -40° to 250°F VIEW HTG-230 https://catalog-api.greenheck.com/api/product/en-us/738 HTGR-250 Round design provides up to 13½ in. wg differential pressure; velocity up to 4000 fpm; and temperature range of -40° to 250°F. VIEW HTGR-250 https://catalog-api.greenheck.com/api/product/en-us/739
