COMPLETE ROOFTOP SPRING CURBS In 1982 we showed the following method for increasing deflection by suspending units from springs on top of a steel frame work and using the CMAB curb without springs as the seal. There were 3 or 4 very successful installations, but the method was too cumbersome and expensive. We found the…
CURB MOUNTED ALUMINUM BASES NOMINAL 1”(25mm) DEFLECTION Not too many years ago, cooling towers and curb mounted exhaust fans were the only pieces of mechanical equipment to be found on rooftops. This has all been changed as curb mounted air conditioning equipment is commanding a larger share of the market. While rooftop equipment manufacturers do…
K Concrete Welded Base Concrete bases are recommended under pumps as they are more rigid and a better choice in maintaining alignment. They need not be selected for the additional mass that is needed under highly unbalanced machines such as slow speed horizontal or vertical compressors. If the building can handle the added weight, floating…
WF Steel Beam Base A complete steel base is not required for equipment such as Absorption Machines, Reciprocating Compressors, Shell Mounted Centrifugal Compressors, H&V units, etc. Steel members improve stability, lower operating heights and in the case of H&V units prevent distortion of sheet metal legs or base angles. The use of saddles and brackets…
WF Steel Beam Base Our very early specifications merely called for “sufficient base rigidity” to handle belt tension and keep the drive in alignment. There had been no criteria for base stiffness or design and every vendor had his own version of what might be minimally acceptable as there never was a unified code. Pump…
WB Horizontal Thrust Restraints It is not unusual to encounter problems where the horizontal combined air thrust exceeds 10% of the equipment weight. If the spring columns alone resist a 10% force, they will lean over about 12% of the rated deflection. This is the recommended maximum. When the thrust is higher, the best solution…
Hanger – Obsolete 1965 WHS Hanger The W30 hanger is satisfactory for duct isolation since ducts vibrate at lower frequencies than piping and there is no high frequency component requiring a full LDS Rubber element. This simple spring hanger retains the 30° capability, but the housing is manufactured so that it may be attached to…