Introduction
The document discusses a new series of semi-hermetic compressors by FRASCOLD SpA, specifically designed for trans-critical applications using CO2 (R744) as a refrigerant. These compressors are tailored to manage the challenging conditions of trans-critical CO2 cycles, which are not suitable for standard compressors.

Design and Development
The compressors are engineered to function at pressures up to 130 bar. The development utilized advanced software tools such as 3D CAD with kinematic simulation, finite element method (FEM) structural analysis, and fluid-dynamic modeling. This meticulous design process led to the creation of the TK series, noted for their reliability and performance.

Specifications
The TK series comprises four models with displacements from 7.89 to 14.45 m3/h. Notable features include a high-efficiency electric motor, a durable spheroidal graphite iron housing, reliable lubrication via an oil thrower disk, and safety valves for both suction and discharge areas. The compressors are designed to minimize noise and vibration due to the thick iron cast.

Standard Equipment
The compressors are equipped with several standard features: high-strength iron housing, safety valves, high-efficiency motor, IP54 protected electrical connection box, thermal protection for motor windings, PTC thermistor for discharge temperature protection, and self-lubricating bushes with a special coating.

Technical Data
The document provides comprehensive technical data, including electrical specifications, refrigerating capacities, and operating conditions. The compressors are optimized for efficiency under specific conditions, such as a 50Hz power supply, ambient temperature of 32°C, and suction gas superheating of 10K.

Application Range
The compressors are versatile, with specific models designed for various refrigerating capacities and operating pressures. The document includes detailed charts and tables that illustrate the performance characteristics and application limits of each model.

Dimensional Drawings
Dimensional drawings and descriptions of components like pressure plugs, oil level sight glass, safety valves, and discharge valves are included, offering a comprehensive view of the compressor's design and functionality.