Corrosion-free Polyvalves from Kerotest Manufacturing come in standard and full-port design, from 0.5 to 12-in. diameters. The valves are made of medium and high-density polyethylene.
Corrosion-free Polyvalves from Kerotest Manufacturing come in standard and full-port design, from 0.5 to 12-in. diameters. The valves are made of medium and high-density polyethylene.
 
Kerotest engineers used FEA software from Algor Inc. to optimize the polyethylene valves. The software will also assist as the company designs higher-pressure water valves.
Kerotest engineers used FEA software from Algor Inc. to optimize the polyethylene valves. The software will also assist as the company designs higher-pressure water valves.

Engineers at Kerotest Manufacturing Corp., Pittsburgh (www.kerotest.com), turned to FEA to design standard and full-port, natural-gas valves in plastic. "Our goals were to make a line of polyethylene valves that outperform the competition, offer more features, and cost less," says Richard Conley, chief engineer at the company. Conley's team selected FEA software from Algor Inc., Pittsburgh (www.algor.com), to optimize the valve designs.

The team used FEA to identify excess material on initial Polyvalve designs while maintaining consistent structural integrity. "The ODs at the ends must match standard pipe diameters," said Conley. "But inner and outer diameters of the valve's center need a wall thickness that withstands working pressures. Emerging trends in the gas industry pointed to a maximum design pressure of 125 psi. That's more than the current industry standard."

Richard Adams, senior design engineer at the company, and Conley experimented with many designs to find the best wall thicknesses and shapes for the valve interiors and transitions to connecting pipe. Their changes removed material in some places and lowered stresses in others. "The design passed prototype testing on the first attempt," says Adams. The next step is to use FEA and design the valve to meet water industry standards, which call for higher pressures and different safety factors.