A large part of my friend Glenn’s work in the maintenance department of a small power plant in the Philadelphia, Pa., region is to ensure the plant’s “wellness” by making sure that workhorses like valves, actuators and regulators work properly.
“How do you do that?” I asked him.
“We drain the tank first, then shoot cotton through the piping and valving,” he replied. “We use filters and strainers. It all helps get rid of moisture contamination, which seems to come from everywhere.”
Does such maintenance shut down the plant? You bet. But as a Val-Tex Web site video reiterates, “Valve maintenance is crucial to the safe and economical operation of all distribution and transmission systems.”
Steven Driscoll from Check-All Valve also thinks large solid debris in media flowing through many types of check valves is problematic.
“The debris or scale can adversely affect valve sealing and operation. Adequate filtration and proper valve selection minimizes this problem,”
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“We also see problems related to wrong valve-sizing or improper upstream conditions, meaning immediately downstream of an elbow.”
When it comes to best practices, especially those that can help avoid plant shutdowns, Driscoll said he advises customers to size valves properly and select springs judiciously. To maximize valve life, make provisions for uniform non-spinning upstream fluid flow.
“For media that is dirty and cannot be avoided or filtered, scheduling routine cleaning is needed,” he said, a preventive maintenance step that is too often overlooked.
Size matters
Driscoll’s firm makes F1, F6 and FP flange insert valves, which can be used as check valves, low pressure relief valves and vacuum breakers, depending on the spring setting used. This, according to the manufacturer’s literature, is a simple and economical way to install check valves in a piping system.
As bolts are installed and tightened, the valve body positions itself. Typically in a flanged joint, one gasket is used; but here, two are required. Flange insert valves are intended to fit between two mating ANSI flanges. The valve’s spring housing inserts into the upstream pipe, thus helping to center it in the pipe. According to Check-All, the FIV Class 150 and 300 valves (F1) are designed for standard schedule pipe or Class 150 or 300 flanges, while FIV Class 600 (F6) valves are made for schedule 80 pipe or Class 600 flanges.
The West Des Moines, Iowa, firm dedicates itself to the design and manufacture of spring-loaded check valves, and also designs a number of custom valves known as “CAVs’’ for mid- to large-size OEM’s.
“We work with our customer’s engineering departments to determine their individual application requirements and perform such services as 3-D CAD design and valve sizing to manufacture a custom tailored check valve that meets their needs,” said Sales Manager Brian Strait.
His counterpart, Russ Hellmer, a regional Check-All sales coordinator, added that time spent up-front in proper valve selection is time well spent.
“Proper sizing, material selection, media free of debris and proper maintenance are all important in preventing downtime over the life of the valve,” said Hellmer, adding that this includes valve placement as well.
Some don’ts …
The latter is particularly key. One Check-All installation tip cautions, “do not install the valve next to the discharge of an elbow ‘ell’ or directly after any component that could alter or disrupt the flow pattern.”
