Pure-Gard Passes Rigorous Testing with Flying Colours

Pure-Gard is a revolutionary safety product that has passed rigorous cleanability testing

Monday, April 17, 2023

Ready to take your production line cleanliness to the next level?

Look no further than Pure-Gard, the revolutionary safety product that has passed rigorous cleanability testing with flying colors. In this blog post, we’ll explore the details of a Riboflavin Test Validation white paper originally published by PSS Engineering in July 2019 that confirms Pure-Gard's compatibility with sanitary environments and CIP/SIP procedures.

As an integral safety component of any process system, rupture discs provide immediate overpressure protection of process equipment. Within the hygienic process industries, rupture discs must also operate as part of a hygienic or aseptic envelope. This means they must be easily cleanable by either dismantling them for cleaning or following clean-in-place (CIP) or steam-in-place (SIP) protocols. The validation of a component’s cleanability is confirmed via a spray device coverage test, commonly called a “Riboflavin Test”. Riboflavin tests are primarily designed to evaluate an equipment’s cleanability in an existing or new system as part of a factory/site acceptance test (FAT/SAT).

So how was Pure-Gard put to the test?

PSS Engineering, a designer and manufacturer of high-purity processing equipment, assessed Pure-Gard’s cleanability using a Riboflavin test carried out in accordance with ASME BPE Appendix L (ASME,2016). In this real-life system test, Pure-Gard was integrated into the vessel head of a purified water storage and subjected to the most difficult cleaning angle to ensure the worst-case scenario. The test was carried out with a static spray ball cleaning device. This satisfies the current industry standard for a spray device in the hygienic industry and ensures that following a successful test, performance with a rotary spray device will produce similar or superior cleaning results.

The Test Procedure

  1. All sample rupture disc devices were sprayed with Riboflavin mixture whilst dry, and viewed under UV light to check their fluorescence.
  2. The devices were then affixed to the tank nozzle (with all tank internal surfaces dry) and cleaned for two minutes.
  3. The rupture disc cartridges were then removed and inspected with a UV light.
  4. After the device was left to dry in ambient air, it was inspected using a 6mm borescope to ensure any crevices were fully cleaned and all Riboflavin residue was washed away.

And the Result?

Pure-Gard displayed exceptional cleanability against the benchmark sanitary cleaning test to ASME BPE standards. The process side of the disc offers a hygienic and cleanable aseptic surface. All evidence of the Riboflavin had been removed after a cleaning cycle of two minutes.During the cleaning cycle, it was observed through a sightglass that the spray pattern from the cleaning device rebounds from the opposite side of the nozzle to the shadowed area and wets the inaccessible surfaces. This rebounding spray was enough to generate a cleaning action on the shadowed part of the device.This shows that Pure-Gard’s design has been thoughtfully considered to minimize L/D ratios, allowing the process side of the disc to be fully exposed to a cleaning device. The disc assembly within a flanged cartridge remains robust throughout operation and maintenance activities.


Pure-Gard is the ultimate solution for companies seeking a fully cleanable, high-performance rupture disc for their hygienic process industry operations. This revolutionary product has the potential to improve process performance and overpressure protection while reducing the overall cost of ownership for safety products. Whether you're retrofitting your existing system or specifying a new one, Pure-Gard is the game-changing pressure relief solution you've been searching for.