Scan the QR Code for more information
Integrity. It’s critical in your systems, and structures
-- and in the people you trust them to.
Structural Integrity’s engineering
strength comes in many forms --
from our 30+ years of experience, to
our team of over 200 engineering
experts, to our experience with
many power plants and gas and
hazardous material containing
pipelines in the industry.
You can also look to us in the following areas for
our ability to link theory and practice:
• Knowledge of power plants, codes, and how things work.
• Extensive experience and leadership.
• High quality, hard work, and responsiveness.
• Custom, integrated equipment, software and solutions.
Call us today to put our
engineering strength to the test.
formed very locally; essentially a vapor bubble forms in the
water, and when it dissolves there’s a lot of energy and over
time as that occurs repeatedly and continuously, it causes pit-
ting in the metal of the blade. It eats away the metal, which
given enough time will completely eat away the metal and you
can have a hole clear through your blade.”
Hammond says the problems that Wanapum experi-
enced are pretty common to any hydraulic system, includ-
ing pumps and motor boat propellers.
Grant PUD had to decide whether to fix the turbines or
replace them. They compared options. They found that new
turbines could increase efficiency and eliminate failures,
A “very unique requirement” in the contract for the manufacturing of the turbines specified that they be free from
“When the manufacturers of the turbines saw that requirement in our contract they said, ‘Well, look, you can’t
do that. Nobody has done that.’ But we required it and they
did it,” Hammond said.
Voith Hydro was surprised to see that requirement, said
Richard Donelson, manager of hydraulic engineering design
for Voith Hydro. Undaunted, “Voith Hydro took up the challenge – which was beyond our previous level of technology
– by making the turbine as large as possible. The guide vane
circle was increased and the new design replaced the existing
20 wicket gates with 32 much shorter gates. The runner was
lowered in elevation to accommodate the larger runner and
fully spherical discharge ring.
“This provided some additional submergence for the turbine which resulted in improved cavitation performance.
Even with all these changes it was still a challenge to develop a runner that could meet the requirements of the specification,” Donelson said.
Initially, blade designs were assessed with computational
fluid dynamics. The winning designs were then developed using physical model testing, according to Donelson. “The final
design was then witnessed by PUD in an independent laboratory and selected for the prototype contract,” he said.
HELPING FISH PASS SAFELY
Grant PUD has a dual mandate at Wanapum dam – produce
power and help fish survive the passage through the turbines.
Voith engineered the new Kaplan turbines to solve both
“The redesigned Wanapum turbine runner was one of the
first to make use of Voith Hydro’s patented Minimum Gap
turbine runner technology, which was developed by taking
a scientific approach to reduce hydraulic losses, fish strike
and mortality, cavitation, and large pressure gradients,”