Quick Action Rupture Disc Changer

Quick Rupture Disc Changer: An easy and safe device to change in the blink of an eye blew up rupture discs

ONIS Quick Rupture Disc Changer (QDC) developed by ONIS permit to One operator to be back in production with an optimal safe and precise overpressure relief system thanks to a rupture disc without using tool and permit to save equipment integrity, save production time and the efficiency of the pressure relief protection.

3D comparison between traditional rupture disc replacement vers an Onis Quick Rupture Disc changer.

Technical sheet

Picture of an Onis Quick Rupture Disc Changer.

Why using a QDC ?

Rupture discs are used in order to protect upstream installations from overpressure. The purpose of this pressure relief system is to blow up and keep the integrity of the assets. This rupture disc can be used as primary level or secondary level. Main applications of rupture disc are in different industries as chemical, pharmaceutical, steel or power industries.

Used in primary level of protection, the rupture disc has to be changed each time it has been activated. Handling a QDC can be interesting if the frequency of activation is high.

When a rupture disc was used as a secondary pressure relief device, it acts as a mechanical barrier of the downstream equipment against corrosive and chemical attacks.

In this second application, the rupture discs can be checked or change each time is required (each pressure relief valve setting operation which can be every 6 months due to country regulation).

The QDC protect the overpressure but also the corrosion of the downstream pressure relief valve and contributes to limiting the OPEX of the unit.

The QDC can be equipped with two rupture discs in order to proceed to a very quick change or one rupture disc and one blinding disc to permit the operator to do a safe positive isolation of the downstream equipment for maintenance. Thanks to QDC, time opening of the pipe is drastically reduced and limit exposure of operators and environmental risks.

How it works

One rupture disc is on line while the other is on hold outside of the pipe.

As for a ONIS line blind, the gaskets are accessible for checks or change while the process is running.

As soon as the rupture disc have been activated or need to be checked, After draining the pipe and open the by-pass, one operator will proceed as well as a standard ONIS Line blind : The flange’s spreading movement is generated by efficient and reliable synchronized eccentric shafts which allows the displacement of the slide gate equipped with two rupture disc holders.

Nota : there are only 2 gaskets on line.

This quick-action clamping mechanism is self-locking and resistant to overpressure and vibration


When your process is back in production, the maintenance team has all the time to change the activated rupture disc.


ONIS QDC make you rupture disc change operation safe, efficient and profitable.

Technical specifications

All Quick Rupture Disc Changers are designed following these specifications:

  • Forged bodies up to 40”
  • Spreading design with no internal mechanism
  • Perfect sealings – 100 % full bore
  • Motorisation available


  • Dimensions Flange to Flange is depending on the rupture disc characteristics.
  • For estimation : please contact us.

For any others ratings or design conditions fill free to contact ONIS.


Mechanized / Automated

When design conditions, safety or project required the ONIS devices can be motorized in order to facilitate the handling of the ONIS equipment.

Pneumatic, hydraulic or electrical actuators can be adapted on any ONIS device.
Automation can also be adapted with live reporting to the local or remote control room.
So, perform a remote positive isolation, rupture disc change or filter replacement is available with ONIS technology.

Custom designs

For each equipment, design conditions and media are requested in order to check the compatibility or the design of ONIS equipments.

Even if ASME Code is used for calculation and design, any project of customers’ specifications can be followed on demand as :

  • Materials
  • Specific design for congested area
  • Welding overlay
  • Weight restriction
  • Explosion proof requirement
  • Specific limit switches
  • Motorization
  • Firesafe

And so, ONIS engineers team are available to define with the end user the specifications and performance objectives

pictures (2)
Onis device firesafe test bench

High performance services for multiple applications