Why Ball and Butterfly valves are preferred over Gate valves?

Ball, Butterfly and Gate valves essentially perform the same function. However, their structural qualities are different. Ball valves have a stem and ball, which turns horizontally, and are commonly referred to as “rotational” valves. Butterfly valves have a stem and a disc, which function very similiar to a ball valve. They are best suited to applications requiring on/off control without pressure drop. Gate valves open by lifting a rectangular gate (or wedge) out of the path of the fluid

Why Ball and Butterfly valves are preferred over Gate valves?

Ball, Butterfly and Gate valves essentially perform the same function. However, their structural qualities are different. Ball valves have a stem and ball, which turns horizontally, and are commonly referred to as “rotational” valves. Butterfly valves have a stem and a disc, which function very similiar to a ball valve. They are best suited to applications requiring on/off control without pressure drop. Gate valves open by lifting a rectangular gate (or wedge) out of the path of the fluid. The sealing surfaces between the gate and seats are flat, so gate valves are often used when a straight-line flow of fluid and minimum restriction is needed. To learn more on the basic guidelines to selection criteria of valves read "5 Questions you must ask before you buy Industrial Valves?" [Click Here] to read my earlier post on the subject. Before you decide on why ball and butterfly valves are preferred over gate valves you need to understand the difference between the rotary and linear movement of the sealing parts with regards to the direction of flow. I have explained the same in the chart below.

To understand better i have listed the advantages of Ball and Butterfly valves as well as advantages and disadvantages of gate valves in the slides below.

Isolation valves in the flow industry serve the primary function of on/off in most process flow applications. For many years piping design engineers preferred gate, globe valves for these funtions. However whenever quick shut off was required ball valves, butterfly valves were a much preferred option due to 90degree open close function. Over the years with more modern valve automation solutions in the market, the valve is no more the primary source of selection. In todays market place gate valve and globe valves are being fast replaced by ball valves and butterfly valves due to their many advantages. The latter are much easy to operate, 90degree open close function, more compact in size thereby occupying less space and last but not least the ease at which these valves can be automated at a much lower cost. Among all of these factors the ease of automation of ball and butterfly valves are gaining much popularity among manufacturers as well as piping design engineers. These days with more versatile designs in metal seated ball valves and butterfly valves they are fast becoming much sought after even for high temperature and high pressure applications.