Some valves are a little stickier than others. Some are a lot stickier.
Operators at ValeroÂs refinery in Memphis, Tenn., had been suffering with an especially troublesome snort valve for several years until they got some help from their friends at VRC Co., Emerson Process ManagementÂs sales representative in Brunswick, Tenn. The 24-in Fisher 8532 butterfly valve and its accessories are part of the 186,000-bpd refineryÂs anti-surge application on its fluid catalytic cracking (FCC) unit.
The valveÂs system also includes a Size 80 1061 piston actuator, go switch, manual operator, trip valve, accumulation tank and boosters on both sides of its cylinder. The valve itself is normally closed, opening only when a process upset occurs to release pressure to the atmosphere. This application also includes a 30,000 hp compressor and occupies a Class I, Div II area.
Zac Scott, VRCÂs account manager, reported that Valero needed to ensure that the snort valve opened when needed. However, the refineryÂs high temperature process and the valveÂs metal bearing had combined to increase friction within it.
Unfortunately, if the snort valve ever failed to open, the refinery could lose $275,000 per hour because of the FCCÂs going down. Meanwhile, the valve would have to be disassembled and shipped to Houston for repairs, which could total $2 million. Scott says these repair costs and 12 to 15 days of lost production could quickly push the overall bill to $99 million.
ÂAnd thatÂs a relatively conservative estimate, says Scott, who presented ÂThe $99 Million Valve this week at the 2007 Emerson Global User Exchange. ÂThis is just a butterfly valve, but associated with a really critical application.Â