RFI: weld repair procedure development for creep-aged high-pressure turbine rotor discs (ESKOM)

Closing date: 20 January 2027 at 10:00 (South African Standard Time).

No briefing or site visit is mentioned.

Enquiries and clarifications:

• Contact: Palesa Mauwane
• Email: [email protected]
• Telephone: +27 11 800 5914
• Available: 08:00 to 16:00 (SAST), Mondays to Fridays, excluding public holidays and weekends.

Submission address: Eskom E-tendering site at https://eTendering.eskom.co.za

Submission method: electronic upload only via the Eskom E-tendering site at https://eTendering.eskom.co.za. No hard copies accepted.

• All documents must be in PDF and Excel format.
• Maximum upload size per document: 500 MB; total submission limited to 4 GB.
• No zip or condensed files allowed.
• If resubmitting, only the latest version is accepted; previous submissions become null and void.
• Submission status must be marked as complete.
• Late submissions are not accepted.
• Submissions must be in English.
• Returnable documents: complete Part B Response Sheet, including contact details, company registration number, and responses to Eskom's questions.

This is a Request for Information (RFI), not a formal bid evaluation. Eskom will use responses for information gathering and market testing. No scoring or preference point system is specified.

• Respondents must demonstrate technical capability and proposed methodology.
• The response sheet asks for evidence of relevant experience in weld repair procedures for creep-exhausted HP, IP or LP turbine rotor discs.

Scope: Development, qualification, and implementation of an approved weld repair procedure for creep-exhausted high-pressure (HP) turbine rotor discs. The methodology should be extendable to intermediate-pressure (IP) and low-pressure (LP) rotor discs across the Eskom fleet.

Key requirements:

• Mock-up work: draft pre-WPSs, qualify WPQR on test pieces, and qualify welding operators in accordance with ISO 15614-1 L2 and ISO 14732. Optimise WPS parameters to achieve desired mechanical and metallurgical properties.
• Material specification for Hendrina Rotor Disc: 28CrMoNiV4-7 or 30CrMoNiV5-11.
• Develop a technically sound, industry-compliant repair methodology in the form of an Engineering report.
• Hendrina stage 1 rotor disc: 144 blades; stage 2 disc: 145 blades.
• Validation and qualification of the repair procedure must include: initial damage assessment, identification of high-stress areas (via modelling), machining requirements, base material condition assessment after machining, possible transition or buttering layers, weld build-up sequence, detailed post-weld heat treatment (PWHT) methodology, non-destructive testing (NDT), machining back to design, and final inspections.

Respondents must indicate whether they have experience in developing, qualifying, and implementing weld repair procedures for creep-exhausted HP, IP or LP turbine rotor discs. If yes, provide:

• Description of similar projects successfully executed.
• Type of rotor discs involved (HP, IP, and/or LP).
• Scope of work performed, including procedure development, welding, heat treatment, testing, qualification, and implementation.
• Relevant industry standards, codes, or specifications applied.
• Details of technical personnel and specialist resources available.

The repair procedure must comply with ISO 15614-1 L2 (welding procedure qualification) and ISO 14732 (welding operator qualification). The weldment must achieve the desired mechanical and metallurgical properties. Validation and qualification must include appropriate engineering assessments and testing, including NDT and final inspections.

Respondents must establish realistic cost estimates and execution timelines for:

(a) Mock-up work: drafting pre-WPSs, qualifying WPQR on test pieces, and qualifying welding operators per ISO 15614-1 L2 and ISO 14732; optimising WPS parameters.

(b) Development of a repair methodology in the form of an Engineering report.

(c) Validation and qualification of the repair procedure through engineering assessments and testing, including PWHT, NDT, and final inspections.

Respondents must provide realistic cost estimates and execution timelines for the three work areas: mock-up work, development of the repair methodology, and validation/qualification of the procedure. No bid security, guarantees, or payment terms are specified.

No specific compliance requirements are stated beyond:

• Submissions must be in English.
• Late submissions are not accepted.
• No specific B-BBEE, CIDB, or CSD requirements are mentioned.

Submissions must be in English. Late submissions are not accepted. All documents must be uploaded in PDF and Excel format via the Eskom E-tendering site. No zip files or hard copies are accepted.

No formal evaluation criteria are specified for this RFI. Respondents must demonstrate technical capability and provide evidence of relevant experience.