Slip-on flanges, also known as ‘hubbed flanges’, have a hub with a very low profile. This type of flange is usually connected to a pipe by one or two fillet welds (one outside the flange and one inside the flange), it is however possible to use only a single weld. Slip-on flanges are produced in many sizes and are favored for lower-pressure applications (ASME class ≤ ۶۰۰).