scope:

The standard for vibration limits in water cooling towers provides cooling tower owners and manufacturers a specification for the acceptable mechanical vibration levels in new cooling towers. This standard is for the purpose of verifying the overall integrity of the cooling tower system and mechanical equipment. It is not intended to be a diagnostic tool to evaluate the source or condition of secondary vibration contributors like bearing faults or electrically induced excitations. Levels of acceptable vibration induced by rotating mechanical equipment are established in this standard for the major materials of construction classifications:

•Wood and Fiberglass Structure Cooling Towers

•Concrete Structure Cooling Towers

•Packaged Cooling Towers of Formed Sheet Metal or Fiberglass

Existing recognized standards for acceptable levels of vibration in industrial machinery provide a basis for establishing vibration limits on water cooling towers. Where applicable, these standards are referenced as source of previously accepted vibration limits on industrial equipment.

It is also recognized within the cooling tower industry that the water cooling tower is an industrial machine with unique characteristics. Relatively flexible supporting structures for rotating air moving machinery can experience somewhat higher levels of vibration within the cooling tower structure compared with rotating machinery supported at grade on concrete (Figure 1.0). Cooling tower vibration limits, therefore, are hereby established by drawing from existing vibration standards and adapting these standards to the unique nature of the industrial water cooling tower.