5.2　Allowable Speeds

5.2.1　In the case of cylinders lubricated，the allowable speed of compressor and corresponding average piston speeds shall be limited to the value specified in Table 5.2.1：

Table 5.2.1　Allowable speeds for compressor

5.2.2　The rotating speed and piston average speed of non-lubricated cylinder shall be less than those in equivalent lubricated cylinder.Unless otherwise specified，the average piston speed in compressors handling saturated hydrocarbon gases and non-lubricated cylinders shall not exceed 3.6m/s.

5.2.3　The maximum product of piston diameter（in mm）and compressor speed（in r/min）should not exceed 272500.The maximum cylinder diameter should not exceed 825mm.In the case of low suction pressure，the piston diameter cannot but exceed this value，the crankshaft rotating speed should be lower，an accumulated successful experience of two or more years is required based on at least two trains of the same type operated under the same or similar conditions，and approved by the purchaser.