Food and Beverage
According to FoodProcessing.com, budgets in 2010 for capital expenditures in the food and beverage processing industry were up more than 19% over what they were in 2009, when actual spending declined by about 8.7%. And research by Industrial Info Resources, released in late November, revealed an even more dramatic improvement when comparing U.S. and Canadian projects tracked in 2010. The number of projects increased 42.5% from 2009 (359 projects) to 2010 (510); investments increased a very healthy 53.8% from 2009 ($3.58 billion) to 2010 ($5.51 billion). The industry is clearly in the throes of recovery and does not appear to have suffered as much as some other manufacturing industries from the economic collapse.
That’s good news for those who work in, and supply to, food and beverage processing plants, including those companies that provide the valves or buy the parts that keep the plants running smoothly. But there remain some challenges that must be addressed, including new safety concerns that may lead to changes in material requirements, as well as potential competition from overseas.
HOW VALVES ARE USED
Valves used in the food and beverage industry can be divided into two major groups: those in direct contact with food materials and those handling utility services (steam, water, etc.). While there are regulations applying to both, those for the first group are more stringent, since they involve direct contact with food.
On the food-contacting side, things are regulated by standards from various independent organizations: 3-A Sanitary Standards, Inc. and NSF International, the Food and Drug Administration (FDA) and more. The inside of the valve, for example, must be smooth enough to avoid trapping particles of food or allowing bacteria to accumulate; this usually translates as 15 to 20 microinches arithmetical mean roughness (Ra).
Any soft material in the valve, adds Karl Lutkewitte, product manager at the Steriflow division of Jordan Valve, must meet similar roughness criteria, and must not absorb or hold the product going through the valve. There also should not be crevices where material can be trapped to later decay, nor should there be dead volume in which there is no movement, thereby allowing material to stagnate.
Most food-contacting valves are made of 316 stainless steel for corrosion resistance (or 316L if the valve has welded end fittings), Lutkewitte says, although other alloys are used for certain applications. In the pharmaceutical industry, which uses valves similar to those used in food transference and faces similar challenges, there also may be restrictions on the ferrite content of the 316 (including use of 316L) to help prevent rouging, which is an accumulation of iron oxide, hydroxide or carbonate on the inside of valves, tubing or vessels (resulting in colors ranging from red to black). Rouging “is viewed as a potential place where microorganisms—bacterial, virus, biofilms—can make a home,” says Lutkewitte. “It’s thought that if you minimize that ferrite content to no more than 3%, you minimize the probability that rouging will occur.”
Another important difference between general application valves and those made for food service is that the food-related valves tend to be forged or machined out of bar stock, rather than cast. “Castings are frowned upon [in food service],” says Lutkewitte, because they are more likely to have pores, while “forgings are more dense with no hidden cavities in them.”
In some areas, the requirements for food valves are less stringent than for those used in other industries, Andy Butcher, product market manager, Spirax Sarco, points out. One reason is that the pressures involved tend to be lower, and aside from the chemicals used for clean-in-place (CIP) operations, they’re not subjected to some of the highly corrosive service of industries such as chemicals. “On the utility side, where we’re controlling, for example, steam going to a heating vessel, they tend to be general service control valves,” Butcher says. With fairly low-pressure, low-temperature steam going through them, such valves will generally be made of cast iron or carbon steel, he continues, although some companies elect to spend the extra money and use stainless.
Still, those CIP chemicals can be a challenge, according to Wayne Labs, senior technical editor of Food Engineering magazine, who wrote an Oct. 1, 2010 article entitled: “Tech Update: Clean-in-Place Equipment.” CIP chemicals are becoming stronger, that article says, and this has led some valve makers to use AL-6XN, a corrosion-resistant, iron-based, austenitic stainless alloy, in place of 316. There also are claims that AL-6XN is more resistant than 316 to certain forms of rouging.
At first glance, it would seem that, except for lead-content regulation, few changes to regulations applying to valves in food service applications have occurred. In 2007, the pasteurized milk ordinance (PM) changed the way mix-proof valves could be used in CIP applications, but the 3-A standards have been around for many years. Still, taking a broader look, the picture looks less clear.
Butcher explains that he sees some confusion about exactly what applies to the industry. “I think the food & beverage industry in general is pretty much in turmoil with regulations and standards for all of the processes in food and beverage coming down from the FDA and others,” says Butcher. He explains that at a recent food safety summit he attended in Washington, DC in early 2010, a general topic of discussion was “exactly which regulations should be enforced, how often the FDA should be inspecting plants, and even when they’re inspecting plants.” The industry in general is not sure what standards are applicable, he says.
In the area of food safety, further evidence of the state of flux occurred last fall when S. 510, the FDA Food Safety Modernization Act was debated. (The act passed both houses and was awaiting presidential signature as of press time.)
One area under regulatory/legislative debate is lead content in plumbing, including valves. In 2006, California passed AB 1953, which effectively bans lead in excess of 0.25% in any plumbing for potable water. The law became effective at the beginning of 2010, and the evaluation process for materials is described in NSF/ANSI Standard 61 - Annex G.
Vermont has a similar regulation, and attempts to create similar laws in other states have occurred, as well as an attempt to create a federal rule. An NSF standard that will supercede Annex G, NSF 372–Drinking Water System Components–Lead Content, is pending, as is the federal Get the Lead Out Act, H.R. 5289, which addresses lead levels. While these two lead-level measures have more weight for the water segment than the food industry, Jeff Kane, sales and marketing manager, DFT Inc., says he sees the issue of lead in equipment creeping into the food industry in a major way soon. Looking at the bright side, however, he views the increased focus on clean water regulations as a business opportunity for the valve industry. “There’s been more and more emphasis on water and certainly wastewater in the last year or two than we’ve seen in quite a while,” he says. “We look at that as a real growth market.”
CHANGES IN TECHNOLOGY
Some changes are taking place in the way valves are used in the food industry—particularly in the area of automation and control. Lutkewitte cites the increased use of remote setpoint control for pressure regulators as an example. “Instead of a hand crank to increase the setpoint,” he says, “you put air pressure on top of that valve.” This technique is showing up more and more on CIP skids and in other areas.
There is also a movement toward not using a pressure regulator at all, but rather using a regular closed loop proportional-integral-derivative (PID) control. “I would say that there’s a move toward stepping away from regulators [and] more towards proper feedback control loops,” says Butcher. The use of electronic sensors, electronic controllers like programmable logic controllers (PLCs) and electronic systems that can talk to a central control room, can provide “constant feedback as to exactly what the temperature in the cooking vessel is, and where the valve positions are,” he says. This helps users maintain records of the temperatures that have been used to cook foods, but also, in maintenance of the control loop and the control valve, the data is “something they can’t get from a remote setpoint regulator.”
However, going to full PID loops can be costly, and not all plants or applications can justify the move. Lutkewitte explains that remote setpoint control of a pressure regulator is cost effective in sizes below 11⁄2 inches. A small company—like a small soup factory—may continue to use pressure regulators, but larger firms are moving toward PID control, says Butcher.
Butcher sees another technical trend occurring: more use of electric valve actuators and positioners, instead of pneumatic. One reason is that a lot of the big plants are discontinuing the use of compressed air-operated equipment in their production processes. He’s seeing it at “one of our big [customers], in fact, based in the Netherlands, and in Europe, where the standard valve they buy is electrically operated because it’s been that way for a long time, and now they’re starting to enforce that on the U.S. headquarters of their company.”
One drawback to electrical valve actuation in a food plant involves the environment in which that actuation is used. “It’s quite often difficult to provide an electrically operated valve that’s suitable for an environment where they’ve got to wash-down to maintain cleanliness,” he explains. With wash-down, there’s an inherent shock risk with electrically actuated valves.
In many industries where valves are used, foreign-made products, especially from Asia, have had an impact on what’s happening in America. However, “I don’t see that an awful lot in food service valves, in all honesty,” says Butcher. While some effect has occurred in product types such as isolating ball valves, when it comes to control valves, “most U.S.-based food companies still are using U.S.-based manufacturers. I don’t think I’ve been around plants where I’ve seen a miscellaneous control valve from China, unless it’s come in on a packaged system” such as a CIP skid, he says.
Lutkewitte, on the other hand, has observed considerable competition in some areas of the world. It’s strong in Asia—India or China, he says—especially in food and to some extent in oral pharmaceuticals, but not as much in more closely regulated pharmaceuticals.
The competition may soon increase, however, in areas where the country is toughening standards. In India and China, for example, “Both countries are making … a good effort at becoming certified to meet FDA [current] good manufacturing standards (cGMP).”
In contrast Kane, whose company makes primarily high-end check valves, hasn’t seen much foreign competition. “If we were battling commodity against a commodity, it would probably be tough,” he says, but because his company produces high end, plants usually come to them for answers to more difficult applications—performance requirements that can’t be met with low-cost imported goods.
A LOOK AHEAD
The economic slowdown of the past few years has affected the food industry the same way it’s affected the rest of the world, but the worst seems to be over, according to the people interviewed for this story. In general, the food industry suffered less than other segments of the economy, but what was affected has also started to recover. Lutkewitte attended a pharmaceutical show recently and found the mood to be upbeat, if still sober. The recovery in that industry has not occurred in “stunning amounts,” but the situation is certainly better than the previous year. The situation in the food industry seems even better with more projects underway, he says.
Butcher echoes these sentiments. “We monitor food production rates quite closely as part of our marketing,” he says, “and we certainly see food production looking very favorable at the moment.” He says growth began in 2009 and is expected to increase for the next couple of years.
As with the rest of the valve industry, those who buy for or sell to the food industry are looking forward to better economic times. However, while people will always need food and companies to manufacture food products for them, the economy is still not out of the woods. Valve makers and users should tread carefully as they keep an eye both on the sometimes-confusing pronouncements of regulators and on the growing involvement of overseas manufacturers.
Peter Cleaveland, a contributing editor to Valve Magazine, writes extensively about issues related to the flow control industry. Reach him at firstname.lastname@example.org.
CLASSES OF ROUGING
While rouging tends to be more of a problem in high-purity pharmaceutical applications, it is also a potential danger in food processing. There are three classes of rouging on stainless steel. Class I involves materials carried from upstream (often from pumps), and no valve material can prevent it completely. Class II, caused by a breakdown of the passivation of the metal surface, is affected by choice of material. Class III appears in the presence of high-temperature steam, and can exist in a glossy black (and generally harmless) or a powdery black form. The glossy form appears more frequently on electropolished surfaces, while the powdery form appears more on unpassivated mechanically polished surfaces.
Little information is available on the effect of changes in material. According to a February 2004 article by Richard E. Aver in the newsletter of the Boston area chapter of the International Society for Pharmaceutical Engineering, Class I and II rouging could be stopped by a nitric-hydrofluoric acid pickle or nitric acid passivation, or by an electropolish followed by a nitric acid passivation. As for Class III rouging, it “cannot be removed by simple cleaning but must be removed chemically or by grinding,” followed by chemical passivation, according to Corrosion Doctors. “Once the system is back in service, it will turn black once again, but hopefully not forming the powdery black film.”