POS-A-SET® Rupture Disc

Two sides to the POS-A-SET rupture disc

As system pressure approaches the burst pressure setting on the ultra-low positive pressure side, a girdle is loaded until it deflects back past a knife-blade assembly in the holder. As the girdle passes the knife blade, the seal is divided in a triangular pattern to relieve the pressure.

CAL-VAC rupture discs vs. POS-A-SET rupture discs

The difference between the CAL-VAC and the POS-A-SET is the orientation of pressure relief components. The CAL-VAC relieves ultra low-pressure in the vacuum (negative) pressure direction, while the POS-A-SET rupture disc relieves ultra-low pressure in the positive pressure direction.

On the higher-pressure side, the perforated metal top section, under tension loading, relieves pressure in the direction opposite the girdle. It incorporates CDC’s seven hole pattern at the apex of the rupture disc dome. Together, the seven-hole pattern and six pre-cut sections create a non-fragmenting design.

Additionally, the top section’s pre-punched holes provide optimum flow through the disc when relieving ultra low-pressure through the girdle.

Both designs:

• Relieve pressure as low as 1 inwc differential
• Are dual-acting, providing both both positive and negative pressure protection
• Can be made to meet 3A sanitary standards when used with a sanitary fitting holder assembly
• Provide lower maintenance costs and greater reliability compared to a valve, increasing your system productivity
• Do not include moving parts, eliminating the possibility of mechanical malfunction