Double Way Rupture Discs | DonadonSDD Donadon SDD - 1
Double Way Rupture Discs | DonadonSDD Donadon SDD - 2
Double Way Rupture Discs | DonadonSDD Donadon SDD - 1
Double Way Rupture Discs | DonadonSDD Donadon SDD - 2

Double Way Rupture Discs | DonadonSDD

DonadonSDD Bidirectional Rupture Discs

DonadonSDD DIF and LPD bidirectional rupture discs are designed for equipment protection against both overpressure and vacuum conditions. These are single-use safety devices: after activation, the disc must be replaced and the root cause of the rupture investigated as part of standard maintenance procedures.

DIF Type

The DIF is a composite, four-part conventional rupture disc: perforated metal section, sealing membrane, protective cover, and calibration ring. Installed between flanges, it is suitable for gases or liquids under static conditions. DIF discs can be mounted below safety valves to isolate the valve from corrosive or contaminated process media, reducing valve maintenance and leakage risks.

  • DN: 2"–40"
  • Burst pressure: 0.5–5 barg
  • Tolerance: ±5% to ±20%
  • Operating margin: up to 70%
  • Temperature: up to 265°C with PTFE/PFA membrane, up to 480°C depending on material
  • Vacuum/counter-pressure support: available
  • Detection: electric, magnetic, inductive, or optical sensor options

LPD Type

The LPD is a flat composite disc for very low positive or negative pressures. Typical applications include storage tanks, atmospheric vessels, silos, and biogas systems where equipment pressure or vacuum resistance is limited.

  • DN: 2"–20"
  • Burst pressure: 5–500 mbar g
  • Operating margin: up to 60%
  • Temperature: up to 265°C
  • Fragmentation: none, except membrane
  • Vacuum/counter-pressure support: available
  • ATEX EX II 2 GD: available

Materials and Applications

Available in stainless steel, Alloy 201/400/600/625, Alloy C276, and titanium. Membranes can be PTFE, PFA, stainless steel, or aluminum. Selection is based on operating pressure, burst pressure, temperature, DN, flange type, process media, vacuum/counter-pressure, and rupture detection requirements. Suitable for chemical, pharmaceutical, energy, and storage applications.

Description

DonadonSDD DIF rupture discs are composite conventional discs formed by four parts:

a slotted, perforated metal part

a seal membrane (usually in PTFE but also available in many other metallic or non-metallic materials)

a protection section

a calibration ring

This disc has been designed to be mounted between flanges.

It is excellent for use with gas and liquids in static conditions and excellent for low pressures.

DIF discs react to excessive pressure with total opening in a few milliseconds.

They are therefore recommended for valve protection. Supports may be provided for vacuum or counter-pressure protection.

Composite DonadonSDD rupture discs may also be used for simultaneous protection from pressure and vacuum.

ModelDIF
MaterialsStainless steel, Alloy 201, Alloy 400, Alloy 600, Alloy 625, Alloy C276, Titanium
MembranePTFE, PFA, Stainless steel, Aluminium
DimensionsDN 2”(15) – DN 40”(1000)
Rupture pressure0.5 - 5 bar g (depending on material and diameter)
Tolerancefrom +/- 5 % to +/- 20%
Operating temperaturemembrane in PTFE/PFA max 265°C, up to 480°C (depending on the membrane)
Operating marginup to 70%
Vacuum supportAvailable
FragmentationNo (membrane only)
Use under valveYes
Corrosion resistanceGood - can be protected with a PTFE membrane
LiningsYes
ContainerMounted between flanges
Rupture sensorElectrical, Magnetic, Inductive, Optical
PED Certification [CE STAMP]Available
ATEX EX II 2 GD CertificationAvailable

DonadonSDD LPD model discs are a simple, reliable, accurate and economical solution for applications requiring extremely low pressure protection (positive or negative).

Their primary use is to protect processing and storage tanks, atmospheric vessels and silos with low design pressures, and therefore only able to withstand slight pressures and vacuums, against implosion or rupture.

A specially interesting application is in the protection of biogas digesters.

DonadonSDD LPD rupture discs are flat composite discs formed by four parts:

a slotted, perforated metal part

a seal membrane (usually in PTFE but also available in many other metallic or non-metallic materials)

a protection section

a calibration ring with blades to improve membrane rupture

DonadonSDD LPD discs open without fragmentation to prevent product contamination and can be customised to meet a broad range of non-standard specifications and applications.

LPD discs can be designed:

for dual pressure and vacuum protection

to resist vacuum or counter-pressure conditions

complete with a burst detector

ModelLPD
MaterialsStainless steel, Alloy 201, Alloy 400, Alloy 600, Alloy 625, Alloy C276, Titanium
MembranePTFE, PFA
DimensionsDN 2"(50) – DN 20”(500)
Rupture pressure5 - 500 millibar g (depending on material and diameter)
Tolerancefrom +/- 5 % to +/- 20%
Operating temperatureup to 265 °C
Operating marginup to 60%
Vacuum supportAvailable
FragmentationNo (membrane only)
Use under valveYes
Corrosion resistanceGood - can be protected with a PTFE membrane
LiningsYes
ContainerMounted between flanges
Rupture sensorElectrical, Magnetic, Inductive, Optical
ATEX EX II 2 GD CertificationAvailable

Certifications

Quality certifications are a guarantee. DonadonSDD has obtained the following certifications.

DonadonSDD provides high-quality products that meet the safety requirements of the systems where they are installed. The organisation and procedures fully comply with the ISO 9001 standard to ensure the utmost quality for our products. Our quality system has also met the stringent requirements of the UNI EN 9100 standard concerning design, development, and manufacture of rupture discs for the aerospace industry.

DonadonSDD products – such as rupture discs, explosion venting panels, and rupture indicators – are certified in compliance with PED directive 2014/68/EU or ATEX directive 2014/34/EU. The rupture discs alone are manufactured, tested, and certified in compliance with ASME directive, Section VIII, Division 1 and carry the relative UD stamp. 

DonadonSDD is subject to inspections carried out by 3-A Sanitary Standard, Inc. (3-A SSI) so that our rupture discs can meet the highest sanitary standards.

Upon request, our clients can ask independent inspectors to certify single batches.

DOWNLOAD CERTIFICATIONS