For which pipe sizes are screwed joints limited in refrigeration piping intended for pressures of 1750 kPa and higher?

Screwed joints in refrigeration piping are limited by the size of the pipe when the intended pressure is 1750 kPa and higher due to the potential for joint failure under high-pressure conditions. In this context, for pipe diameters less than 31.75 mm (1¼ inches), the threading may not provide sufficient strength to withstand the internal pressure, making these joints potentially unsafe. This size limitation is based on safety standards and practices within the industry aimed at preventing leaks and ensuring the integrity of refrigeration systems.

The use of larger diameter pipes with screwed joints can effectively manage the stresses caused by high-pressure refrigerants, making it possible to utilize these connections safely above the specified pressure. Thus, the limitation set at less than 31.75 mm helps to ensure that materials and connection methods are appropriate for the operating conditions, enhancing overall safety and operational reliability in refrigeration systems.