Valdes Provides Concrete Solutions

As part of our commitment to providing value-added results here are a number of proven case studies from our satisfied customers.

High Energy Piping Surveillance

Piping and pipe support problems sometimes cause forced outages at older power plants. Valdes Engineering Company's highly experienced pipe stress analysis group has developed a surveillance program designed to evaluate existing piping installations.

These evaluations are performed without incurring the high cost of reanalyzing the piping or the need for inspection scaffolding. As a result, Valdes has been retained by several Midwestern utility companies to conduct high energy piping surveillances at dozens of their units, focusing initially on main steam, hot reheat and cold reheat piping with follow-up inspections every three to four years. Due to the success of this program, many inspections have resulted in the addition of the boiler feedwater and extraction steam piping systems.

Valdes typically performs the following tasks as part of the High Energy Piping Surveillance program:

  1. Review of original design documentation, subsequent modifications and both past and current problems.

  2. Hot and cold walk-downs of the piping and supports are performed. "As found" load settings for the variable spring hangers and position indicator readings for the constant support hangers are recorded. Elevation measurements to identify slopes to the low point drains are recorded to determine if significant sagging and/or thermal bowing problems exist.

  3. The engineering review of the hot and cold walk-down data provides corrective recommendations. Normally, only hanger adjustments are required.

  4. The recommended pipe support adjustments are then made during a scheduled outage and Valdes inspects the adjustments thereafter.

  5. A post-adjustment hot inspection is typically performed by Valdes after start up.

  6. Valdes issues a final report containing the data recorded from the initial hot and cold walk-downs, adjustment recommendations and post adjustment (hot and cold) walk-down data.