- Published on Wednesday, 21 January 2009 01:00
- Written by Peter Cleaveland
What can you do to help your company get through these most-challenging times? We spoke to North American valve and actuator manufacturers, who provided tips on how valve users can operate their flow control systems to achieve maximum efficiency-and profits.
TIP 1: Energy Savings Pay Off
One way to save money, often with a minimal investment, is to cut down on energy use. While most companies have already taken a few steps in this area, there are many ways to save on energy costs. Some are as simple as stem packing, but they can make a big difference, says Andrew Norman, president of growth and technology for Dresser Masoneilan and Dresser Consolidated. This is because poorly adjusted or aging packing can mean leaks and loss of plant media, and since there are gaskets and seals throughout a plant that can be sources for leaks, taking care of the potential problem can save considerable money.
"Customers with high-volume steam use should routinely check their steam traps for steam leaks, and repair or replace faulty traps," advises Rick Boylan, sales correspondent, Richards Industries. "A single leaking trap with a 3/16-inch orifice can waste up to 390,000 lbs. of steam per year (assuming a 50 psig differential and a plant operating 300 days per year)."
Boylan also suggests reducing recurrence of trap failure by "replacing cyclic bucket and disc traps (violent cyclic action causes metal wear) with longer-lasting modulating trap technology." Karl Lutkewitte, product manager, Richards Industries, adds that companies with process-critical, large-capacity heat exchangers need to note that "trap failures can directly affect the quality of temperature-sensitive products."
Another way to save steam is to use lift plug valves in certain slurry applications, says Dale Friemoth, vice president of technology & business development, Crane Fluid Handling. Such valves consume purge steam only while stroking the valve open or closed, he says, as opposed to ball valves, which in similar situations would continuously purge steam. "This results in a typical annual savings for one 10-inch valve of 8 million lbs. of steam or nearly $16,000 at $2.00/1,000 lbs.," he says. (See page 18, "Savings Are in the Air.")
TIP 2: Be Smart about Maintenance
When times are tough, cutting back on maintenance may seem logical, but not when production or safety might be affected. A valve failure costs much more than the maintenance that would have prevented it, and an accident or spill can be catastrophic. In fact, a slow time can be an opportunity to "send those maintenance people out there to perform the maintenance that we probably should have been performing when times were good," says Rich Oaks, marketing manager, AUMA Actuators.
Jim Knox, president, Allied Valve Inc., agrees and adds that this maintenance would include checking the packing and pressure seals on valves. Forgetting to do this, he continues, leads to leaks, which can mean paying someone to come in and stop those leaks or risking valve damage.
TIP 3: Bring in Outside Help
A formal asset program can carry significant upfront cost, and firms strapped for cash may not be in a position to conduct such programs. Fortunately, however, it is fairly inexpensive for consultants to help rationalize many maintenance practices. Even such simple things as reworking trim or changing operating conditions of a valve in the process can provide significant improvements. Consultants have the tools to log and record maintenance records on every valve.
Some manufacturers can supply software that allows both end users and suppliers to access the plant's maintenance database directly to allow for "things like shared inventory programs or automatic restocking once they do use parts," says Dresser's Andrew Norman. As a result, "they're never in a shutdown situation where they don't have the parts," he says.
TIP 4: Use Smart Instruments
Another excellent way to rationalize maintenance is to use smart digital valve controllers-their built-in diagnostic capabilities and data logging can help spot a problem before it causes a shutdown. Bruce Grumstrup, director of instrumentation, Fisher Controls, Emerson-Fisher Valve Division, cites this example at a chemical plant: A controller caught a problem that "if the valve had failed they would have lost the catalyst, and it would have been many, many weeks shut down trying to get the catalyst." The same type of digital diagnostics can also keep an operation from pulling out and tearing down a valve that has nothing wrong with it.
And, of course, smart digital valve controllers have the potential to provide better control of the process. These controllers require upfront investment, but as Grumstrup says, "with thinner margins out there, you've got to make sure your process is bullet-proof. And the control valve has always been at the heart of making sure that your process works properly." Start that bullet-proofing where things are most critical, he advises, either with respect to uptime or optimizing the process, "because in general, it's not a place to scrimp. In fact, it's a place to focus your efforts in a time when you're trying to squeeze the last drop of profit out of the pipeline," he says.
TIP 5: 'Exercise' to Keep Fit
Sometimes the smallest action can ?create large savings. For example, Oaks suggests that when part of a plant is shut down, it's a good time to periodically exercise the valves and actuators. "Don't shut down the process and then two years later start it up and expect that automated valve in place for two years will operate flawlessly as if it's been operated regularly," he says. Grumstrup agrees, but points out that it depends on the process. "If you've got a steam line and there's no steam in it, I don't think it's a problem," he says.
Knox adds that it's also a good idea to go out and occasionally hit the zerk fittings with some lubricant. He explains that one of the problems with actuators and gear operators on valves occurs because dirt gets in between the stem and the bushing. "This stuff gets as hard as a rock, and the next thing that happens is they end up damaging the stem," he explains. A little attention before that can occur is certainly less expensive than spending $5,000 on a new stem. But with lubricated plug valves, in particular, some people "don't read the fine print that says every time you use them you need to relubricate them, so they come back a year later and try to operate the valve, and they can't because the lubricant that was in there is all hard," he says.