It may be desirable to use a heavier gauge metal ring permanently mounted to the seat area of the plastic or metal seal. This assembly is called Type DR rupture disk. When two rings are used, the assembly is called Type DRR rupture disks. When vacuum is involved-in any amount the seal MUST have a structural support. Standard support for Type D disks is the same as that used with Type B disks, a domed structure with pie shaped segments or a laser cut single piece construction, depending upon size and pressure rating.
Support is mated to upstream or pressure side of seal.
All three components are permanently attached. This assembly is called Type DV rupture disk. When a DV disk is specified and high vacuum is involved-in the micron range a soft gasket ring should be applied to the seat of support on the process side. This assembly is called Type DSV rupture disk. This assembly is called a PLD rupture disk.