Coupling Applications for Special Purpose Machinery Multiple Flexible Membrane Types

Panel SessionPg. 193-198Special purpose machinery applications of flexible disc couplings with multiple convoluted diaphragms or disc packs at each end of the spacer are discussed. Couplings in this category were retrofitted on two compressor trains at a large ethylene plant. The couplings were a 44,000 hp multiple convolution flexible disc coupling and a 25,000 hp bolted disc pack flexible disc coupling. The installations were retrofits, as part of a program to uprate the compressor trains beyond the original mechanical ratings, at a minimum cost and with limited machine downtime. The user had overall engineering responsibility for selection of the type of coupling, and performance of the total installation. Selection of the coupling type, coordination meetings, design audits, quality control and installation procedures, and contingency plans were done with the full cooperation of the coupling, compressor, and turbine vendors. This resulted in uprating the trains with a high degree of reliability made possible by the careful application of these types of couplings. Based on experience gained from these installations, the following are problem areas: • Multi-convolution coupling application • Disc pack coupling application • Quality control and installation procedures These comments are meant to convey experience with specific flexible membrane couplings, and to suggest considerations that may be applicable to them, and not to exclude other vendors, designs or circumstances that may be available or may result in different decisions or selections