Jim Lenihan, Gemco Valve President, is a contributor to the March edition of Powder Bulk Solids. Featured in the “Ask the Expert” column. Lenihan responds to a variety of questions regarding valve function and safety.
Jim Lenihan has worked in the valve and seal industries since receiving his Engineering degree from UL (University of Limerick, Ireland) in 1983. Throughout his career, he has held positions in manufacturing, material management, engineering, product management, sales and marketing. Jim has been president of Gemco Valve Company since 1997. Gemco Valve specialize in valves for solid processing applications from sugar to lunar regolith. Jim has worked on solving valve and seal problems for the Chemical, Pharmaceutical, Food, Plastics, Steel, Power and Nuclear industries worldwide.
Q. What is a good way to define the real weight above the valve and the real torque necessary to open and close the valve?
Estimating the real weight of product above a valve and its effect on valve torque is very complex, with factors such as the apparent density of the product, the shape and size of the particles, the mixture of different material, the shape of the container, moisture content, and many more affecting the outcome. Often the most cost-effective method is trial and error. In the absence of empirical data a simple lab test can yield good information. Companies like Jenike & Johanson have a lot of experience with bulk solids and could help.
Here, an expert from Choosing Your Gemco Valve explains. “When handling solids a higher factor of safety is used to calculate seat torque requirements. The factor is typically 1.5 instead of the 1.25 used for liquid and gas valve calculations. For solids that “set-up” or harden oversized actuator and specially designed discs that can break through the hardened cake are used.”
Also a ball disc which opens and closes within its own spherical radius and does not have to “lift” product tends to work better than flap or butterfly valves. Cont.-
“Powder/Bulk Solids is a terrific resource for the dry processing and solids handling industry. It was great to be included as their valve expert in this edition,” Jim said.
The Powder Handling Solutions Supplement of the March issue of Processing Magazine features Gemco Valve’s case study of their Retractable Sleeve and Inflatable Seal. The study shows how the valve and seal were successfully customized for a leading research based U.S. pharmaceutical company to resolve major dusting issues at one of their largest production facilities. Processing Magazine, has been providing information and solutions for the processing industry for 25 years
