As the fluid or gas moves through this type of valve it must change direction. This results in increased resistance to flow. For this reason this type of valve is not ideal for venting of steam retorts. Globe valves are ideal for use on water and air lines where close control over flow is required. Globe valves have a positive shut off feature which can prevent leakage of air and water into retorts during processing.
Ball valves can provide a bubble tight seal.
Butterfly valves are normally used as throttling valves to control flow. Butterfly valves may be found on some of the newer retort systems 6. When the diaphragm is raised or lowered by the valve stem flow is increased or decreased through the valve. Diaphragm valves may be found on some of the newer retort systems. Free flow valves such as the gate or ball valve are normally used on steam retort vent lines.