Valves in cleanroom processes
08/01/2007
Valve makers look for market boost from biopharm industry
By Robert McIlvaine and Ann James, The McIlvaine Company
Valves for the food and beverage, cosmetics, biotechnology and pharmaceutical, and semiconductor industries are classified in three levels of cleanliness: sanitary, aseptic, and ultra-high purity. Food and beverage uses the terms sanitary or aseptic. The biopharm may tend to use sterile as well as aseptic and sanitary. Semiconductor manufacturers use the term high purity when referring to valves used for their processes.
Valves in these industries are both plastic and metal, mostly 316L stainless steel. The finish in the biopharm valves is a very consistent fine surface-mostly 20 RA, but sometimes as fine as 8 RA. The valve internal surface finish in the semiconductor industry uses 5 RA as a standard. Many of these valves are made in an ISO Class 3 cleanroom. Valves are either welded to the pipe or clamped in place, especially where there is concern about purity. Stainless steel’s corrosion resistance results from a protective passive film on the surface. The objective of this process is to safely put a layer of chrome oxide on the wetted parts. This treatment eliminates any particles of iron bearing dust and dirt left on the surface during fabrication and polishing operations and any oxide scale residues from welding operations.
Valves in aseptic processing and cleanrooms must be suitable and rated (pressure, temperature, or caustic capable) for clean-in-place (CIP) or sterilization-in-place (SIP). The valves also are made to be self-draining and without threads or any crevice on any wetted surface. This is done to prevent a “hold-up” volume of water, condensate, or process fluid, eliminating places for bacteria to grow.
Food and beverage industry
In the food and beverage industry, the valves are made of 316L stainless steel. Many of the valves are rising stem control or on/off valves. These valves are placed in the process line, packaging area, or aseptic filling operation. Valves in this industry are 80 to 90 percent pneumatically operated. In order to seal off the process line, a PTFE ring is added to the valve. The valves are made to self-drain if installed vertically and options can be added to allow horizontal installation to self-drain. Back pressure and throttling valves are also used in this industry. Butterfly valves are common in this market, and diaphragm valves are particularly effective for filling applications. Key elements in diaphragm selection include media compatibility, resistance to compression, regulatory compliance, flex, and closure performance.
Much of production in the cosmetic industry is similar to the food and beverage industry; however, skin product process requirements are more like those in the pharmaceutical industry, which require a much higher concern for quality.
Biotechnology and pharmaceutical industry
In the biotechnology and pharmaceutical industry, valves are mostly 316L stainless steel. Valves in the biopharm industry are found on process, high-purity water for injection (WFI), and utility (air, gas, and steam) lines. Typical valve types include diaphragm, ball, or globe (also called seat) valves. These valves are placed in low pressure lines. The valves are mechanically polished, then electropolished. These are corrosion resistant. In the biopharm industry, the water used is purified, which means that the FDA places tight regulations on the quality of the water in terms of the biological content. WFI is pyrogen free. Purified water is not as demineralized as ultra-pure water used for semiconductor processing, but purified water is still corrosive. In the water loops, the valves are on/off and either manually or pneumatically operated. Regulators are also routinely used in these loops for back pressure control. About half of the valves are manual and half have pneumatic actuators. Roger McCormack, a project manager at Gemü Valves, says, “Newer manufacturing plants utilize fieldbus network control systems. The benefits include superior process control, quality control, and lower operating costs.”
Biopharmaceutical production is a batch process. As a result, cleaning after each batch is extremely important; many valves are used specifically in the cleaning steps. Typically less than 10 percent of the total valves are used to control or regulate process fluid, clean steam, or a utility gas or liquid. Examples would be the use of control valves to regulate some process inputs and the control valves or regulators to control the flow or regulate the pressure of clean steam (process heating and SIP), caustics (CIP), WFI, and clean gases. Rising stem control valves and regulating valves are typically used for these applications because they are more accurate than ball or diaphragm valves for automated control applications.
The majority of total valve content is on/off diaphragm valves, and, to a lesser extent, ball valves. These on/off valves are used in WFI, CIP processing, SIP processing, process fluids (which are almost all water and protein based), and other utilities such as acids or bases for pH control, sparge gases such as CO2 and O2, and vent gases. As mentioned previously, pressure and flow rates of these gas streams are routinely regulated by rising stem control valves and regulators, and there are diaphragm valves used in the same lines for on/off control. The process line valves are used in such areas as growth media feedstock and sometimes finished products.
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Biopharm valves are typically more strictly regulated than the food and beverage valves, as the continually developing guidelines for ASME PBE prove.
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The biopharm companies are watching for rouging, which is a discoloration and degradation of the 316L in the piping or valves that leads to contamination. Rouging is the result of the formation of iron oxide, hydroxide, or carbonate either from destruction of the passive layer or from outside sources. The color variation ranges from orange to red to black. In the presence of hot, high-purity steam, these systems turn from glossy black to powdery black, thus contaminating the liquid or steam. Even electropolished systems with an average surface roughness of less than 10 micro-inches can rouge. Investigations into the source of rouging (or any foreign contaminant) can shut a plant down for weeks, costing millions of dollars in lost production, not to mention investigation labor costs.
Semiconductor industry
The semiconductor industry uses ultra-pure water in its processes. Those valves are made of PVDF. The valves are on/off and pressure relief in the size of 1/2 inch to 12 inches. More valves in this market are manually operated rather than actuated. The valves for ultra-pure water applications are diaphragm or butterfly types. They are made in a cleanroom and then double-bagged. Once in operation, the valves are sterilized with chemicals or in a CIP process above 200°F. Semiconductor plants also use stainless steel for their gas lines.
Valve manufacturers
Very few valve manufacturers sell to all of these industries. Although many of these manufacturers make very highly engineered valves and could sell to more industries, they mostly specialize in one area. For example, Fujikin sells mostly semiconductor valves. Gemü offers products to all three; however, they mostly sell to biopharm as do Crane Saunders and Richards Industries. Waukesha Cherry Burrell specializes in the food and beverage industries.
Future trends
Technical innovation is a mainstay of these markets, which are constantly developing new products and processes. What trends will change these industries? Karl Lutkewitte, product manager at the Jordan/Steriflow Division of Richards Industries, sees two trends in the biopharm industry. One is related to the implementation of process analytical technology (PAT). He believes that the implementation of PAT will eventually lead to continuous processing rather than the batch/continuous batch processing now common to biopharm manufacturers. As continuous on-line analytical measurement technology grows, allowing the industry to get quality and contamination issues under control, and as regulatory bodies become convinced of the value of those technologies, the biopharm industry will find creative ways to continuously process its product. This continuous process will call for new valve technology and extremely tight DCS/PLC automated control with integral validation management.
The second trend, Lutkewitte believes, has to do with productivity improvements and cost control. As worldwide competition increases, throughput and process availability metrics are going to become more important as measures of operational efficiency. Likewise, waste and utility costs will begin to gain focus. It is not that these metrics aren’t monitored now; it is just that they aren’t as relatively important as they will be in a more mature, competitive environment, or as they currently are in other mature industries. In the early days of the petrochemical industry, these key profitability measurements were not as closely monitored as they are today.
Carl Taylor, global business manager of Crane Saunders, has noticed other trends such as the increasing use of disposable bags, tubing, and valves mostly found in components or smaller systems. Another trend Taylor has seen is the ability of the valve companies to machine several valve bodies out of one block of stainless steel. Saunders has made up to 8 or 10 diaphragm valves from a single block. This one block of valves is more hygienic than putting 8 to 10 valves in a welded manifold.
Markets
Valves in the semiconductor, food, and pharmaceutical industries are not only used in clean applications but also in the transport and treatment of incoming water as well as wastewater. They are also used to transport process liquids in non-clean areas of the plants. In the aggregate only 50 percent of the investment is for pumps for clean applications.
The market for cleanroom valves will rise from $2.964 billion in 2007 to approximately $3.635 billion in 2010. The biopharm industry will be the largest purchaser, followed by the food industry, then the semiconductor industry. Other applications include aerospace, medical devices, nanotechnology, and miscellaneous painting and industrial applications in which clean environments are required.
The revenues include both valves and parts but only those sold by the valve manufacturers. They do not include parts sold by third parties. The U.S. will remain the largest purchaser due to its strong position in the food and pharmaceutical industries. China is in a strong second place due to its rapidly growing process industries and specifically growth in electronics.
Changes in the industries and demand for a cleaner environment will lead to change in the valves and computer control of these valves. The road to increased profits is through better technology.
Robert McIlvaine is president and founder of The McIlvaine Company in Northfield, IL. The company first published Cleanrooms: World Markets in 1984 and has since continued to publish market and technical information for the cleanroom industry. He can be reached at [email protected].
Ann James is the pumps and valves market editor for The McIlvaine Company. She can be reached at [email protected].