he Type D Composite Bursting Disc consists of a slotted metal top section and a plastic or metal seal membrane located at the concave or pressure side of the top section. The top section is the pressure zone and controls bursting rating of disc. Since the top section has open slots, the seal isolates it from process media and prevents leakage. Like the Type B Solid Metal Bursting Disc, the Type D composite disc is dome-shaped with an angular seating arrangement. Pressure is applied to dished or concave side, subjecting disc metal to tension loading.

Seal material in the Type D bursting disc is thin and subject to damage by a foreign substance on seating surfaces or flanges. 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 bursting disc. When two rings are used, the assembly is called Type DRR bursting discs.

When vacuum is involved-in any amount the seal MUST have a structural support. Standard support for Type D discs is the same as that used with Type B discs, 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 bursting disc.

When a DV disc 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 bursting disc. If a DR ring is also attached to the atmospheric side of the disc, the assembly is called Type DRSV.

When it is desirable to protect the metal top section of a Type D disc from contaminants in a valve, header, piping, or atmosphere; a plastic liner can be attached on the convex side. This assembly is called a PLD bursting disc. A plastic liner covering and isolating a built-in support from process media becomes a PLDV bursting disc. In severe applications, metal exposure may not be desirable, hence the plastic covering.

Specifications

Available Sizes

Types D. DV, DR and DRSV
Full range: l' thru 44'
Standard sizes: l'thru 30'
Type PLD:
Full range@ l' thru 44'
Standard sizes: l' thru 24'
Type PLDV.
Standard sizes: l' thru 24' (full range)

Pressure

Full range: 0.5 to 2000 psi 0 72'F (22-C) Minimum/maximum pressures for standard sizes
and combinations of disc materials: See pages 3 thru 8.

Temperature

FEP plastic seal: -40'F (-40'C) to 400'F (204'C) maximum
TFE plastic seal: -40'F (-40'C) to 500'F (260'C) maximum
Metal seal: -320'F (-196'C) to1000'F(538-C)
Cycle life for 'D' discs may be greatly reduced
at temperatures lower than -40'F (-4o'(1)

Top Section

Standard metals: 3l6 SS, lnconel/Alloy 600, Nickel/ Alloy 200, Monel/Alloy 400
Special metals: Hastelloy C-276/Alloy C-276, Titanium and Tantalum

Seal

Standard materials: FEP plastic, TFE plastic, 316 SS, Nickel/Alloy 200, Inconel/Alloy 600, Monel/Alloy 400, Hastelloy C-276/Alloy C-276, Silver, Aluminum
Special metals: Platinum, Titanium and Tantalum

Vacuum Support

Standard metal: 316 SS, lnconel/Alloy 600, Nickel/Alloy 200, Monel/Alloy 400
Special Hastelloy C-276/Alloy C-276, Titanium, Tantalum
Protective Standard metal: 316 SS. Inconel/Alloy 600,
ring' Monel/Alloy 400, Nickel/Alloy 200
Special: Hastelloy C-276/Alloy C-276, Titanium, Tantalum

Soft Gasket Ring

Standard metal for metal seal: Aluminum Standard material for plastic seal: FEP plastic
*When to use Protective Ring:
16'-24' 15 psig or less

Composite bursting discs for Bolted Flange and Union Type Safety Heads

BS&B Bolted and Union Type Safety Heads both require bursting discs with angular seating design. All standard discs with angular seating are listed on the following pages. Listing is by sizes with a full selection of standard discs for each size.

Minimum and maximum pressures for each disc are shown in psig @ 72' F. and kg/cm2 @ 22' C. Maximum temperatures are shown in 'F. and 'C.

Tolerances

Normal Bursting Tolerances for Type D Series Composite discs:

Manufacturing Ranges

Manufacturing Ranges for Composite discs:

1 Composite discs: Types D, DV, DR, DRR, DSV, DRSV, PLD, PLDV

If Type D, DR or PLD disc will be exposed to vacuum, specify DV, DRV, DSV, DRSV or PLDV. Standard materials for vacuum support are 316 SS, lnconel/Alloy 600, Monel/Alloy 400, and Nickel/Alloy 200. Special materials are Hastelloy C-276/Alloy C-276, Titanium and Tantalum.

Standard material for protective ring with DR discs is 316 SS. Other metals available.

TFE plastic for seals is standard from 1 through 8 size. FEP plastic for seals is standard for 10 and larger except when temperature is over 400' F. (204'C), or pressures are less than available with TFE.

11/2 Composite discs: Types D, DV, DR, DRR, DSV, DRSV, PLD, PLDV

2 Composite discs: Types D, DV, DR, DRR, DSV, DRSV, PLD, PLDV