Reverse Acting Rupture Discs | DonadonSDD Donadon SDD - 1
Reverse Acting Rupture Discs | DonadonSDD Donadon SDD - 1

Reverse Acting Rupture Discs | DonadonSDD

DonadonSDD Reverse Acting Rupture Disks

The DonadonSDD KRD, SCR, and Y90 are reverse acting rupture disks. Operating pressure is applied to the domed side; the disk inverts and opens upon reaching the set burst pressure. After activation, the disk opens fully within milliseconds and must be replaced.

Types and Differences

  • KRD: Reverse acting, micro-scored circumference disk for cyclic or pulsating pressures, suitable for liquids and gases.
  • SCR: Reverse/compression disk with 4, 6, or more radial micro-scored segments, petal opening design.
  • Y90: Reverse acting, micro-scored disk for gases and liquids, with optional gas cushion for specific applications.

Technical Specifications

  • Materials: Stainless steel, Alloy 201 / 400 / 600 / 625, Alloy C276, titanium
  • DN: 1"–36" for KRD / SCR, 1"–8" for Y90
  • Burst pressure: 0.41–137 barg for KRD / SCR, 0.2–70 barg for Y90
  • Temperature: -196°C to +480°C for KRD / SCR, up to +600°C for Y90
  • Tolerance: ±5% to ±20%
  • Operating margin: 90%, up to 95% depending on process conditions
  • Fragmentation: none
  • Vacuum support: not required
  • Use under safety valve: permitted
  • Lining: PTFE process side available for chemical resistance

Applications

Used in reactors, pressure vessels, chemical lines, process liquids, gases, pulsating loads, and installations where the disk is installed upstream of a safety valve for isolation from corrosive or contaminated media.

Certifications and Detection

Available with PED / CE, ATEX EX II 2 GD, and ASME UD Stamp for KRD and SCR. Supports electrical, magnetic, inductive, or optical burst detection sensors.

Selection Criteria

Selection requires operating pressure, burst pressure, temperature, DN, medium, fluid phase, pulsating operation, backpressure, non-fragmentation requirement, holder, and sensor type.

Description

The DonadonSDD KRD rupture discs obtained with NS Nanoscored technology are compression or reverse circumference micro-scored discs.

KRD discs make use of the latest sector technology: the camber of the convex disc is not modified by the operating pressure except on reaching reverse pressure. This device works with ratios of up to 95% between operating and rupture pressure and withstands thousands of cycles without jeopardising its reliability.

At the moment of reversion, the disc ruptures in a few thousandths of a second along the scored line without fragments and with full opening. KRD discs have lower sensitivity to variations in temperature with respect to conventional discs and therefore are very useful in applications with large temperature variations.

Thanks to their innovative design, KRD discs can be used in the presence of liquids only, in cycling and pulsating conditions without reduction of safety margins. In addition, they are especially suitable for isolating safety valves. The wide choice of materials and the thickness used make KRD discs very resistant to corrosion. Greater protection can be obtained using a PTFE lining, which can be applied to the process side of the disc.

Vacuum support is not required and they are able to resist high counter-pressures.

ModelKRD
MaterialsStainless steel, Alloy 201, Alloy 400, Alloy 600, Alloy 625, Alloy C276, Titanium
DimensionsDN 1”(25) – DN 36”(900)
Rupture pressure0,41 bar g (6 psi g)- 137 bar g (2000 psi g) (depending on material and diameter)
Kr l0.48
Tolerancefrom +/- 5 % to +/- 20%
Operating temperatureFrom – 196°C up to 480°C
Operating margin90% - Able to reach 95% depending on the conditions of service
FragmentationNo
Use under valveYes
Corrosion resistanceVery good
LiningsYes
ContainerHR/A, HR/P, HR/F, HTC
Rupture sensorElectrical, Magnetic, Inductive, Optical
ASME Certification [UD STAMP]Available
PED Certification [CE STAMP]Available
ATEX EX II 2 GD CertificationAvailable

DonadonSDD SCR Rupture discs obtained with NS Nanoscored technology are compression or reverse discs with micro-scored calibrated sections opening in petals, characterised by the presence of 4, 6 or more radial scoring.

This allows for better opening reducing the risk of petal detachment.

This makes DonadonSDD SCR rupture discs suitable both at high and at low bursting pressure and can be used only with gas and liquids (with the presence of a special gas cushion) also in cycling and pulsating conditions without reduction of safety margins.

SCR discs react to excessive pressure in a few milliseconds without fragmentation.

They are especially suited for protection of pressure relief valves.

DonadonSDD SCR Nanoscored rupture discs allow for a ratio between operating and bursting pressure up to 95% and have a very good resistance to corrosion. Corrosion resistance may be additionally improved with PTFE lining. In addition, SCR discs can be subject to absolute vacuum conditions without need for supports.

ModelSCR
MaterialsStainless steel, Alloy 201, Alloy 400, Alloy 600, Alloy 625, Alloy C276, Titanium
DimensionsDN 1”(25) – DN 36”(900)
Rupture pressure0,41 bar g (6 psi g)- 137 bar g (2000 psi g) (depending on material and diameter)
KRg0.48
Tolerancefrom +/- 5 % to +/- 20%
Operating temperatureFrom – 196°C up to 480°C
Operating margin90% - Able to reach 95% depending on the conditions of service
FragmentationNo
Use under valveYes
Corrosion resistanceVery good
LiningsYes
ContainerHR/A, HR/P, HR/F, HTC
Rupture sensorElectrical, Magnetic, Inductive, Optical
ASME Certification [UD STAMP]Available
PED Certification [CE STAMP]Available
ATEX EX II 2 GD CertificationAvailable

The DonadonSDD Y90 rupture discs obtained with NS Nanoscored technology are compression or reverse circumference micro-scored discs.

The camber of the convex disc is not modified by the operating pressure except on reaching reverse pressure. This device works with ratios of up to 95% between operating and rupture pressure and withstands thousands of cycles without jeopardising its reliability.

At the moment of reversion, the disc ruptures in a few thousandths of a second along the scored line without fragments and with full opening. Y90 discs have lower sensitivity to variations in temperature with respect to conventional discs and therefore are very useful in applications with large temperature variations.

They are especially suitable for use with gas and liquids (with the presence of a special gas cushion) and for protecting pressure relief valves. The wide choice of materials and the thickness used make Y90 discs very resistant to corrosion. Greater protection can be obtained using a PTFE lining, which can be applied to the process side of the disc.

Vacuum support is not required.

ModelY90
MaterialsStainless steel, Alloy 201, Alloy 400, Alloy 600, Alloy 625, Alloy C276, Titanium
DimensionsDN 1”(25) – DN 8”(200)
Rupture pressure0.2 - 70 bar g (depending on material and diameter)
Tolerancefrom +/- 5 % to +/- 20%
Operating temperatureFrom – 196°C up to 600°C
Operating margin90% - Able to reach 95% depending on the conditions of service
FragmentationNo
Use under valveYes
Corrosion resistanceVery good
LiningsYes
ContainerHR/A, HR/P, HR/F, HTC
Rupture sensorElectrical, Magnetic, Inductive, Optical
PED Certification [CE STAMP]Available
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