In the Malaysian food, beverage, and pharmaceutical industries, sanitary diaphragm valves and sanitary butterfly valves are both commonly used in areas where hygiene is important.
However, there are some important differences between the two valves:
Design: A sanitary diaphragm valve has a flexible diaphragm that seals against a weir, while a butterfly valve has a disc that rotates to open or close the valve.
Cleanability: Sanitary diaphragm valves are considered to be the most “sanitary” valve, so they are more cleanable than butterfly valves because they have fewer crevices and dead spaces where product can accumulate and potentially contaminate the process. The flexible diaphragm also makes it easier to clean the valve without needing to dismantle it.
Flow control: Sanitary diaphragm valves offer more precise control of flow than butterfly valves, particularly at low flow rates.
Pressure rating: Butterfly valves are generally rated for higher pressures than sanitary diaphragm valves, making them a better choice for applications that require high-pressure capabilities.
Cost: The main reason diaphragm valves are much less used compared to butterfly valves is the cost. Sanitary diaphragm valves are typically more expensive than butterfly valves, but the added cost may be justified by their superior cleanability and flow control capabilities in certain applications.
NKE Flow is a supplier of sanitary valves. Click to see more about our diaphragm valve, and butterfly valve.