scope:

1.1 SCOPE

1.1.1 This standard covers the minimum requirements for special-purpose couplings that transmit power between the rotating shafts of two pieces of equipment in the petroleum, chemical, and gas industries. In general, a special-purpose coupling is to be designed and constructed for a minimum service life of 5 years for flexible-element couplings, and 3 years for gear and torsionally damped and resilient couplings. The coupling is to operate continuously without interruption for this time period in an equipment train that is normally unspared and is critical to the continued operation of the installation.

1.1.2 These couplings are designed to accommodate misalignment and axial displacement of the shafts without imposing excessive mechanical loading on the coupled equipment. This equipment will usually dictate a coupling that is engineered and manufactured specifically to meet the operating conditions of the equipment train in which it will be installed.

1.1.3 Couplings covered in this standard include gear, flexible element, quill shaft, and selected types for torsional damping and torsional tuning in horizontal applications. All other couplings, including clutch, hydraulic, eddy-current, and general-purpose couplings are excluded from the scope of this standard. Additional requirements may be necessary if a coupling is to be used in a vertical position, or at any other angle significantly removed from the horizontal. In particular, provision may be necessary to support the mass of the spacer assembly.

1.1.4 This standard addresses design, materials of construction, manufacturing quality, inspection, and testing of special-purpose couplings. This standard does not define criteria for the selection of coupling types for specific applications.

Note: Consultation by the user with the original manufacturer of the drive and driven equipment is strongly recommended to assure proper application to this standard when coupling retrofits are planned.

Note: A bullet (•) at the beginning of a paragraph indicates that either a decision is required or further information is to be provided by the purchaser. This information should be indicated on the data sheets (see Appendix A); otherwise, it should be stated in the quotation request or in the order.