Patented Design – Method C has features protected by U.S. Patent #5,301,479 with the following advantages, as compared to conventional installation methods A and B.
Mounting Locations – Methods A and B are mounted on the outside wall of the building over the framed opening. The top of the hood becomes the shipping height of the building, and the floor-to-ceiling height of the building needs to be raised to allow for the bottom of 15″ long explosion proof light fixture to be clear of the top of the door, out of the way of entering forklift load or mast. Method C is mounted securely midway within a 1/4″ thick tubular frame opening. The height of the roof is the shipping height. Internally, the light fixtures, suppression system nozzles, etc. are safe out of the way.
Forklift Damage Protection – Overhead roll-up doors are specified because they receive less damage from forklifts than swing-type doors. However, as in Methods A and B, overhead roll-up door vendors manufacture the hoods at the top of the door out of very thin steel. This means the leading edge of the bottom corner of the hood is frequently damaged by the load or the top portion of the forklift mast. Method C’s leading bottom edge is reinforced with steel angle upon which a 10 gauge faceplate is attached, providing protection against forklift damage. NOTE: 10 gauge steel has, by weight (more is stronger), 281% more steel than 18 gauge, and 642% more steel than 25 gauge!
Fusible Link Operation Reliability – Methods A and B have difficulty in penetrating the roof or wall of the building for the cable release to be attached to a ceiling-mounted fusible link. Considering ice, snow, dirt, debris and vandalisim, the actual release during fire is questionable. Method C has the ideal cable release and attachment for the fusible link protected inside.
Component and Hood Security – Methods A and B, being outside in the weather, could have the operation of the components affected over time by ice, snow, dirt and debris jamming operation. In addition, the hood and components are exposed to damage by vandals and intruder unauthorized operation. Method C has all operating components and hood tucked inside the building, safe from negative effects from outside influences.
Moisture Control – Method A has the bottom of the door curtain stopping at a steel angle that is flush with the threshold opening of the building. This will allow wind-driven rain that may penetrate the joints of the door curtain’s steel slats and/or condensation of moisture to accumulate on the inside surface of the uninsulated steel curtain (fire rated overhead roll-up doors are not the U.L. or FM approved with insulated slats), causing water to drain down into the sump floor of the building. This will cause a false chemical spill alarm. Methods B and C have the angle moved a few inches down from the building threshold so the water cannot get into the sump and drain out a weep hole in the angle. (This is part of Haz-Safe Buildings’ Patent #5,301,479.)
Blast Relief Capability – Large overhead roll-up doors do not have the strength to match the wall’s blast strength and could be used as blast relief in place of relief panels. Blast protection is best if implemented by a dual fan posi-ventilation system which eliminated heavier-than-air chemical fumes so that an electrical or static spark has nothing to ignite, therefore eliminating need for blast relief.
Appearance – The hood, components and chain operator exposed outside the building, as well as jutting out over the roof line, are not aesthetically pleasing in Methods A and B. However, integrating the entire door into the building wall provides a more architecturally smooth surface on the exterior because the awkward looking hood is completely hidden.
Haz-Safe building with overhead rollup doors, each accommodating six pallets (24 drums), two side by side, and stacked three high for a total building capacity of 48 pallets or 192 drums. Forklift never enters building. Explosion proof motor operated rollup doors are controlled remotely by fork lift driver. Building on crawlers, A/C unit removed and crated before rollout. Once outside, the shop’s crane shall lay building over on one side for shipping.