The Long Beach Cam camera, perched high atop City Hall in downtown Long Beach, Calif., welcomes viewers from all over the world to admire the beauty of the coastline, overlooking San Pedro Bay on the south coast of Los Angeles County. Featured prominently in view is a new wave fountain, which runs day and night to entertain and delight visitors to the Queen Mary Events Park and Aquarium of the Pacific. If included in David Macaulay’s book The Way Things Work, even the most seasoned of engineers would find the story of the Long Beach Wave Fountain astonishing.
With water being pumped at the rate of 11,000 gallons per minute, the original fountain design ran into problems immediately. "The water hammering felt like a gunnery range," recalls Dave Edgar, mechanical engineer for the City of Long Beach Branch. "Imagine a thousand pounds of metal objects slamming and pounding all at the same time."
The original poppet solid on-off valves installed on two manifolds caused destructive harmonic vibrations in the equipment when they were opened and closed in different sequences. As a result, the poppet valves failed within days of installation. Finding alternatives — especially in an environment where a test prototype was not an option — required some creative thinking.
Finding a Solution
The Long Beach Wave Fountain presented rigorous requirements, with the municipality establishing strict guidelines for minimal maintenance and reliable performance.
Edgar scoured publications for solutions, and even called fountain engineers at the Bellagio in Las Vegas, but encountered a wall of proprietary systems. Relying on his knowledge of flow control and working collaboratively with Assured Automation (www.assuredautomation.com), his valve supplier, Edgar improved the design with three key changes:
• Adding expansion loops in the pipes;
• Adding hydro dampeners; and
• Replacing the poppet valves with pneumatic Ares angle seat valves with fast-acting solenoids engineered by Assured Automation to control the 150 water jets.
The expansion loops reduced the harmonics, while the hydro dampeners kept the seat from slamming closed, softening the impact. The Ares angle seat valves were selected for their high cycle life, durability and reliability, and compact assembly. "Finding the right valve for our wave fountain was key to the success of the project," recalls Edgar. "Other more common valves could not meet our stringent requirements. We worked collaboratively with the engineers at Assured Automation to find the right solution to meet our specs. And the effort has paid back."
High Cycle Life & Reliability
The Ares valve’s ideal internal flow characteristics, with maximum capacity and high-duty cycle, provide better performance compared to other valve designs. The valve’s piston is unique, enabling the plug to retract farther from the flow path, ensuring the highest flow capacity. The dual packing design and a large diameter self-aligning stem ensures high cycle life.
These 2/2-way pneumatically actuated piston valves were originally designed for liquids, gases, steam, and some aggressive fluids applications. The valve body and internal components are made entirely of AISI 316 SS (Ares Series), and the seals are PTFE, enabling a high chemical compatibility with almost all process media.
The special internal conformation of the valve seat avoids excessive deformation of the PTFE seal at high temperature or pressure, providing long-lasting service. The self-aligning plug design guarantees a high-duty cycle under all kinds of pressure. The valve works well in a temperature range from -14 F to 358 F.
The stainless steel spring and the shape of the dual self-adjusting stem seals ensure tightness through the wear and tear of time. The metal piston coated with a slow-wearing protection and the self-lubricating guides and seals guarantee an almost unlimited life for the pneumatic control section, even through constant use under the extreme conditions presented by the wave fountain.
Compact Assembly
The control head rotates 360 degrees for selective positioning of the pneumatic inlet port. Available in sizes from 3/8" to two inches, the pneumatic valve is small, but packs a big wave with 135 jets for the City of Long Beach’s fountain attraction.
Visitors to the park’s wave fountain are awed by its power and well-choreographed tidal surges. Architectural fountain designers are awed by its simplicity and endurance. The waves are generated by computers, which control the solenoids and drive the valves in an air-tight system. The valves cycle nine times per minute. Two 15-minute shows are run each hour for 10 hours a day. And with 1.5 million cycles in over a year and a half, not a single valve has failed, keeping the fountain running for the world to enjoy.
Bill Farrell has over 30 years experience in the automated valve market. He is currently president of Assured Automation, a supplier of automated and manual valve products to the industrial, military, pharmaceutical, and process industries. Mr. Farrell can be reached at [email protected].
www.assuredautomation.com
