This Practice provides designers and engineers with requirements to help reduce the Total Cost of
Ownership (TCO) of rotating machinery by determining allowable piping loads and piping load
applications.
Comment: Owner experience has shown that designing machinery piping to the maximum
published allowable loads results in low mean time between repair (MTBR) and
higher than acceptable maintenance costs.
This Practice limits the application of the entire maximum allowable nozzle load during the
equipment installation design, allowing some reserve margin to maximize the possibility of the
final installation actually remaining within the allowable loading.
This Practice drives the stated, published and calculated allowable nozzle loads to become more
performance based, tied more closely to actual effects on the MTBR and TCO for the machinery
in order to:
a. Promote the highest reliability for vital or sensitive machinery and the determination of
those allowable loads that will allow the achievement of that reliability
b. Allow spared (essential) machinery to be more heavily loaded, and encourage
manufacturers to either furnish allowable load data or be in accordance with a published
standard
c. Encourage machinery manufacturers to generate more meaningful reliability-based
allowable nozzle load recommendations
d. Encourage standards organizations to look at the basis for their allowable load
values/calculation methods and verify the effects on the demonstrated MTBR and Total
Cost of Ownership (TCO)
This Practice describes the requirements for calculating allowable piping loads and the
application of those loads for rotating machinery including pumps and compressors (centrifugal,
reciprocating and rotary screw), steam and gas turbines, and liquid ring compressors. Also, this
Practice may be used on fans and blowers after consultation with the manufacturer.
This Practice describes the requirements for allowable nozzle loads for vital or sensitive
machinery and for essential (spared) machinery.
This Practice also outlines the requirements for minimizing loads imposed on equipment by the
piping systems.
