We do not recommend the use of automatic flush bolts on pairs of acoustical doors furnished with sound seals. When the doors are closed, and compression gaskets on the frame and astragal are adjusted to seal properly, the automatic flush bolts will not retract when the active leaf is opened. This is because the seal causes the side of the bolt to be pressed tightly against the side of the strike cutout. While the bolt may be retracted by pulling the door tightly against the seals, when the door is closed again the bolt will not automatically enter the strike, since it requires a loose clearance in order to function.
When permitted by local authority, a U.L. listed manual flush bolt should be used in lieu of the automatic type, or use IVES FB51, Door Control 845, Trimco 3820 constant self latching flush bolts. Another alternative is to use the Krieger mullion with a positive latch in each door. Contact us to find out more about this option.
The bottom rod of an inactive leaf of pairs needs to be offset (approximately 1/2", easily done in the field by installer) so as to not interfere with the mortised or cam lift door bottom.