Piping loads that can be imposed on machinery nozzles (such as those of pumps, compressors, etc.) should be restrained within certain limits. Piping designers always want higher allowable nozzle loads to simplify piping designs while machinery manufacturers want smaller allowable nozzle loads to ensure good alignment, higher reliability and fewer complaints about operation. Process plant operators place great importance on long-term reliability of equipment and, so, generally should side with the machinery manufacturers. Regardless, it's essential for all parties to agree upon optimum nozzle loads for any machinery package.
Let's look specifically at nozzle loads for pumps and compressors.
Pump nozzle loads. These are specified in the pump's codes and standards (for example, API 610). The API 610 standard covers nozzle loads for horizontal pumps, vertical in-line pumps and vertically suspended pumps for nozzle sizes up to 16 in. (400 mm). For larger pump nozzles, come to an agreement with the vendor about nozzle loads before placing the order.