Valves used in brewing applications can be divided into two categories: the method of connection and the type of closure system. The first category includes threaded valves, which have NPT threading to connect to pipes, and tri-clover/tri-clamp valves, which use a gasket and clamp to secure the connection. The second category includes two main types of closures. The first is a ball valve, where a quarter turn closes or opens the port completely. The second is a butterfly valve, which has a thin disc that rotates a quarter turn to control the flow.
Starting with threaded ball valves, one advantage is their affordability. However, they have some drawbacks. The threads can retain contaminants and sediments, making them difficult to clean. It is also challenging to access the inside of the valve and remove trapped sediments. Nevertheless, they are versatile, rugged, durable, and commonly used.
The second type is the butterfly valve, which has a tri-clamp connection. This type allows easy disconnection, isolation, and reconnection of vessels or pipes. It offers half and full locking positions for easy identification of valve position. These valves are lightweight and relatively inexpensive due to the minimal material used. Disassembling them for cleaning is not easy as they require tools to open. The closure mechanism, consisting of a disc pressing against resilient silicone, results in less effective sealing compared to ball valves. The seal cannot be tightened, affecting the longevity of the valve. Furthermore, even in the fully open position, the valve is divided by the closure disc, creating a potential area for materials like hops to get stuck and limiting the benefits of a large port system.
There are different types of butterfly valves, including high-performance ones that are more expensive. These valves have an off-center configuration for the closing mechanism, providing certain advantages but also creating a larger cavity that can trap other materials. Another issue with butterfly valves is the potential for sediment to accumulate underneath the disc, making it difficult to clean out.