eNtsa

SPECIALISED ENGINEERING SERVICES

eNtsa specialises in a number of technologies that have been design and built in-house with the aim of servicing the power generation and petro-chemical industries.

WeldCore®

WeldCore® is a Proudly South African material sampling and repair technology for the power generation- and petro-chemical industry. Sampling can be performed up to 23mm deep (8mm diameter). This technology through the efforts of the eNtsa team received international accreditation from the American Society of Mechanical Engineers (ASME).

This friction taper hydro-pillar welding and repair process has saved the local power generation and petro-chemical industries billions of rands. This status has sanctioned the application of the technology in high integrity plants and equipment designed and manufactured accordance of the ASME Boiler and Pressure Vessel Code (BPVC).

Small Punch Test (SPT) and Small Punch Creep Test (SPCT)

The Small Punch Testing facility at eNtsa provides creep rupture and materials characterisation data using small sample methodologies. Through small sample methodologies eNtsa is able to extract material property information from in-service components without compromising the component structural integrity, and can highlight/map plant degradation and serve as a ranking tool to assist with determining remnant life of high value engineering components.

  • Small Punch Static Test (SPT)
    • Deflection rate controlled test (similar to a tensile test)
    • The deflective vs load is recorded, and through FEA modelling, the yield strength and tensile strength is derived
    • Can be adapted to test high temperature properties

  • Small Punch Creep Test (SPCT)
    • Constant Load application with a ceramic ball-punch configuration with argon purged sample furnace
    • Inline load and Deflection monitoring via punch rod
    • Dual, indirect sample temperature control & monitoring
    • Test performed at high temperature (Max 625°C)
    • The deflection vs. time is recorded.
    • Using developed SPCT reference creep rupture curves, remaining life is predicted

Whip Peening

The whip peening innovation was first conceived as a theoretical solution having specific ties to the unique peening requirements associated with steeple groove surface treatment. It would also be feasible to be implemented with the existing equipment developed by eNtsa to perform the serration grinding procedure.

This innovation involves a series of small high-strength tungsten beads, which are spun at a determined peripheral velocity to obtain a desired kinetic energy. The beads are constrained in a spherical dimension about the rotational center by means of a strong, but flexible link (wire, thread or line) allowing partial degrees of freedom to the rotating beads. The beads travel in a planar circular motion owing to the centrifugal reaction force of bead mass and centripetal acceleration creating a whipping action. When the whipping beads are brought into contact with a target surface, the kinetic energy of the beads is transferred to the local contact area resulting in a peening action. With accurate position control, machine parameters such as peening intensity and indentation spacing can be repeatedly achieved regardless of the whip radius.

Turbine Serration Grinding System

eNtsa has developed and implemented a customised solution for refurbishment of Steam Turbine Rotors used in the power generation industry. The system allows for the removal of surface cracks at the blade mounting serrations of fir-tree type blade attachments.