Description
A dual-action rupture disc with perforations and a pre-cut section on one side, and a tab with knife blade assembly on the other, i.e., the reverse configuration of the CAL-VAC.
Our dual-action design allows the POS-A-SET to perform the function of two rupture discs with a single installation point. It relieves low positive pressures (as low as 1 inWC) on one side, while on the other it relieves slightly higher negative pressures. The POS-A-SET's flat-seat, easy-to-clean design reduces product buildup, thus facilitating compliance with FDA requirements.
Relieve ultra-low vacuum or positive pressure conditions with the POS-A-SET high-precision, bidirectional rupture disc.
Our dual-action design allows the POS-A-SET to perform the function of two rupture discs with a single installation point. It relieves low positive pressure (as low as 1 inWC) with a tab and knife blade assembly on one side, while on the other side it relieves slightly higher negative pressure through perforations and a pre-cut section.
Looking for the CAL-VAC rupture disc? Nearly identical to the POS-A-SET, the CAL-VAC relieves ultra-low pressure in the negative direction, the opposite of the POS-A-SET's ultra-low relief in the positive direction. Contact us if you are not sure which one you need.
Two sides of the POS-A-SET rupture disc
As system pressure approaches the burst pressure set point on the ultra-low positive pressure side, a tab is loaded until it deflects past a knife blade assembly in the holder. As the tab passes the blade, the seal splits in a triangular pattern to relieve 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 the pressure relief components. The CAL-VAC relieves ultra-low pressure in the vacuum (negative) 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 tensile load, relieves pressure in the direction opposite the tab. It incorporates the CDC 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.
In addition, the pre-cut holes in the top section provide optimal flow through the disc when relieving ultra-low pressure through the tab.
Both configurations:
Relieve pressure as low as 1 inWC differential.
Are dual-acting, providing protection for both positive and negative pressure.
Can be manufactured to meet 3A sanitary standards when used with a sanitary connection holder assembly.
Provide lower maintenance costs and greater reliability compared to a valve, increasing your system's productivity.
Have no moving parts, eliminating the possibility of mechanical failure.
Nominal Size Range: 3″ – 12″ (80 mm – 300 mm)
Burst Pressure Range:
Positive Pressure: 1 inWC – 115 inWC
Vacuum Pressure: 2 psig – 150 psig (0.138 barg – 10.3 barg)
Maximum Recommended Operating Ratio:
See the POS-A-SET documentation.
Seat Configuration:
Flat seat.
Service:
Liquid or gas.
BDI Alarm System Compatible?:
Yes.
ASME Code Symbol Stamp Available?:
No.
Materials not listed or shown may be available through special design. Contact us for more information.