Session: OAC-03-02/07-01 Monitoring, Diagnostics & Inspection and Plant Life Extension: Aging & Life Management

Paper Number: 62940

Start Time: Thursday, July 15, 2021, 05:00 PM

62940 - Strain Gage Apparatus for Equipment Nozzle Loads 

Mechanical equipment both Static and Rotating are designed and manufactured by specialist suppliers. The system engineers designing a typical pressure vessels and piping systems will engineer the piping systems, but the equipment is engineered to sufficiently specify them from a procurement perspective. There is an important ‘engineering’, ‘commercial’ and ‘performance liability’ boundary limit at the flanges of these equipment between the system engineer designing the system and equipment engineer designing the equipment. This boundary limit is agreed on for the physical aspects for example by defining a universally agreed ASME B16.5 flange size but theoretically agreed for forces and moments that the external piping can impose on the equipment. These equipment are fixed on foundations and hence fixed translational and rotational points i.e. with six degrees of freedom fixed, as compared to the interconnecting piping systems. Hence the thermal effects on the piping systems due to the operating fluids that they carry or due to the environmental change are imposed on this equipment. The equipment has an arbitrary allowable nozzle loads which are three force components and three moment components. A system designer uses current day software to determine these values and ensure the system is imposing force and moment values less than equipment supplier allowable. However, the accuracy of such a calculation is largely dependent on the stiffness of the piping supports, and calculating these stiffness’ is a complicated task. There is also a need to determine acceptable nozzle loads on equipment for their safe and reliable operation. Many such equipment operate in the industry today with successful operating history, and a theoretical design review indicates that the piping system is imposing larger than industry standard specified allowable. Current industry practice does not have tools to measure these external forces and moments, so that their values can be linked to equipment operation and reliability. There is a need for an easy to use, reuse, install and measure apparatus. This paper discusses such a strain gage apparatus that can be mounted on the equipment flange, connected wireless to an electronic instrument and record values. The apparatus can record piping forces and moments imposed during mechanical assembly, gasket seating, system commissioning, start-ups and shutdowns and steady state equipment operation and upset scenarios like water hammer. The apparatus can develop trends for a desired duration. The apparatus can be disassembled and installed on a new equipment and comparison data can be generated to for deciding realistic limits on equipment. This apparatus will typically have three strain gages installed on the machined flange surface. The electrical energy will be provided by battery powered equipment. The apparatus should not encroach upon flange installation during assembly or during equipment maintenance. Critical equipment can have such an apparatus installed permanently like vibration measuring equipment with set acceptable limits. The data from such apparatus will improve confidence in equipment specific design limits and system designs. 

Presenting Author: Bhaskar Shitole Wood Plc

Authors:

Bhaskar Shitole Wood Plc