Mucon Oyster Compact Series Valve – An Improved Pharmaceutical Butterfly Valve
The basic design of the sanitary butterfly valve used in the pharmaceutical, chemical, and food industries has remained essentially unchanged for a number of years. There are a number of detail differences between the products proposed by different manufacturers, and a series of considerations which determine the suitability of such a valve.
Too thin and it can flex under load, especially in larger sizes.
The torque valve from the actuator is transmitted via the stem. Depending on the product being handled, this can be very large, for example with powder sugar if there is any humidity in the atmosphere. There are significant differences in stem thickness between makes of the valve.
The gasket needs to be thick enough and durable enough to provide tightness over a large number cycles. Its seat must be designed so that there is no risk of it becoming detached.
In actuator operated valves, there is an equal and opposite reaction to the opening/closing torque transmitted through the support. If this is not carefully designed, especially in the region where it joins the actuator mounting flange, this can flex in high torque applications, and this can lead to breakage.
In order to achieve optimal mechanical operation, the valve stem needs to be bushed at both ends. Where this is not the case the risk is that over time the valve can get out of alignment and can even lead to metal-on-metal contact and the release of steel particles in the product. Ideally, there will be three bushes, with two on the support end. The bushes themselves should be removed and cleaned separately when the valve is stripped for periodic cleaning. They may need replacement, and it is a benefit if all three are identical.
EASE OF DISMANTLING AND RE-ASSEMBLY FOR CLEANING
Particular points are:
• The ease of fitting of the clamp
• The accuracy of location of the pins holding the support in position in its corresponding hole. In a poorly designed valve, it is possible to assemble the valve without locating this pin properly which leads on tightening the clamp, to irreversible damage to the valve body.
• The weight of the overall valve. Larger valves may need two people to manipulate safely.
Some manufacturers have their own proprietary standards for mounting flanges. More modern designs allow for mounting via standard tri-clamps, which give better compatibility with other components.
GENERAL MANUFACTURING QUALITY
• The quality of welds – no pitting, properly cleaned and polished where necessary.
• No sharp edges.
• High degree of parallelism and concentricity where necessary. No distortions due to short cuts taken during the fabrication process.
• High degree of finish on surfaces in contact with the product to minimize the risk of contamination.
The Oyster™ Compact Series valve addresses all these issues.
This new valve has a re-engineered valve body so as to reduce the overall dimensions of the valve and the weight by around 25% compared to more traditional designs despite retaining the strongest disc and stem on the market.
The valve has three identical bushes.
The patent clamp design simplifies the process of stripping and re-assembling the valve in place, a process further helped by the reduced weight.
It is impossible to close the valve unless the support retaining pin is properly located. The gasket is thicker than most, with a swallow tail seat for maximum security.
The valve comes with Tri-clamp mounting ferrules as standard, machined from solid to ensure maximum precision, concentricity, and freedom from imperfections. Other mounting options can also be supplied: flanges, welding ends, clamp.
Squares and flanges are ISO standard.
Valve is available in sizes from DN 100 to DN 300 (4” to 12”) as standard. Other sizes to order.
The Oyster™ Compact Series valve is fully FDA compliant and is suitable for handling Powders, Granules, Gels or Liquids in the pharmaceutical, chemical or food environments.
The valve can be supplied with a complete range of manual or automatic operation.
FINISHED TO PHARMACEUTICAL STANDARDS
The Oyster™ Compact Series valve is finished to pharmaceutical standards
• Mirror polished Contact surfaces
• Optional full mirror finish available for clean room installations
• Electro-polished or ceramic sandblasted finish available on request