When Is It Not Appropriate To Use A Butterfly Valve?

butterfly valves has simple structure and low cost. It is suitable for large pipe diameters, but may not be suitable for some working conditions due to performance limitations. The following are typical cases and reasons why butterfly valves is not suitable for use, and some suggestions for selecting butterfly valve are put forward:
1.High or ultra-high pressure working conditions
Reason:
Normal butterfly valves sealing structures (e.g. central seal and monoeccentric seal) are difficult to withstand high pressure (usually ≤2.5MPa), which can lead to valve seat deformation, butterfly plate displacement or surface leakage.
Although bi-/ tri-eccentric butterfly valves can withstand high pressure (≤10MPa), they are more expensive and metal hard seals can still wear under extremely high pressure (≥ 20 MPa).
Alternative valves:
Gate valves (more reliable sealing for stop valves), ball valves (hard seal + ball structure, high pressure resistance), check valves (valve core tightly fastened to valve seat for high pressure regulation).
2.Extreme heat or low temperatures
Reason:
Soft sealing butterfly valves (rubber valve seats) have a limited range of temperature resistance (usually ≤120°C, and high temperature media such as steam can accelerate the ageing of rubber);
While hard-sealed butterfly valves can withstand higher temperatures (e.g. bieccentric type ≤425°C), low temperatures (e.g. less than -100°C) may result in brittleness or shrinkage of metallic materials and leakage of the sealing surface.
Alternative valves:
High temperature: metal hard seal ball valves, gate valves (including high temperature resistant packing, such as graphite);
Low temperature: low temperature ball valves (stainless steel PTFE polytetrafluoroethylene and other low-temperature sealing materials), gate valves (anti-freezing design).
3. The medium contains large amounts of particles, suspensions or viscous substances
Reason:
butterfly plate and butterfly valve seat clearance is small, particle media easy to adhere to the sealing surface, causing wear or blockage, especially in the opening and closing process, friction (such as the central seal type).
Viscous media (such as mud and syrup) can adhere to the butterfly butterfly plate, affecting its sealing performance and smooth opening and closing.
Alternative valves:
Knife gate valve (straight structure, suitable for media containing solid particles), plug valve (no surface friction, suitable for high-viscosity fluids), diaphragm valve (rubber diaphragm isolation medium, anti-adhesion).
4. Scenarios requiring precise flow regulation
Reason:
butterfly valve have approximately the same flow characteristics, but at smaller openings (≤ ≤ 20%), the butterfly plate is susceptible to fluid shocks and vibrations, resulting in unstable regulation;
When the pressure difference is large, the butterfly plate may be biased due to uneven force, which affects accuracy.
Alternative valves:
Regulating valves (such as pneumatic diaphragm regulating valves designed for precise regulation), ball valve (V-shaped stopper for precise throttling), check valve (short core travel, high regulation sensitivity).
V. Strict two-way sealing or zero leakage requirements
Reason:
Centrally sealed butterfly valves is usually a one-way seal (press valve seat by dielectric pressure), the reverse pressure may lead to leakage;
Although the monoeccentric butterfly valves can be sealed in both directions, the soft sealing material is easy to age after long-term use, it is difficult to meet "zero leakage" (such as gas, toxic media, etc.).
Alternative valves:
Ball valve (ball and valve seat fully sealed, reliable the two-way sealing), gate valve (parallel gate valve + double seal, suitable for two-way shutoff), check valve + closure valve combination (strictly required to prevent backflow).
6. Small pipe diameter (DN≤50) or limited installation space
Reason:
Although the butterfly valve valve body width is small, it is necessary to reserve room for the butterfly plate to rotate (especially when actuated by a handle), as it may be difficult for the butterfly plate to operate in a extremely narrow space;
In the case of smaller pipe diameters, butterfly valve sealing cover is larger, opening and closing torque may be higher than ball valve or stop valve.
Alternative valves:
Ball valve (compact structure, quick opening and closing, suitable for DN50 and below), check valve (small space occupation, suitable for instrument pipelines).
7. Highly corrosive or abrasive media
Reason:
Ordinary valve body body and sealing material (e.g. cast iron + rubber) are susceptible to corrosion/wear by strong acids, strong alkalis or abrasive media and require frequent replacement;
Although there are fluorine-lined butterfly valves and other anticorrosion types, the lining may fall off or crack after long-term use.
Alternative valves:
Fluorine-lined ball valve (more durable overall lining), diaphragm valves (rubber diaphragm fully insulated media, corrosion resistant), ceramic ball valve (abrasion resistant, suitable for mud, etc.).
Overview: Applicable boundaries of butterfly valves
When selecting valves, a combination of media characteristics (pressure, temperature, corrosivity, particle size), control requirements (cutoff/regulation, sealing class), installation conditions, etc., are considered. Other types of valves are recommended to be given priority if working conditions exceed:
Pressure: soft seal butterfly valve ≤1.6MPa, hard seal butterfly valve ≤10MPa;
Temperature: Soft seal ≤120°C, hard seal ≤425°C;
Medium: Clean liquid (water, gas, oil), high viscosity, does not contain a large number of particles.
If none of the above applies, you can quickly select an alternative solution by consulting the table below:
Recommended valve types
(≥10MPa) Insufficient pressure resistance of closed-cover Ball valve, gate, and check valves
High Temperature Steam (≥200°C) Soft Seal Old Metal Hard Seal Ball Valve, gate valve
Dirt particles Sealing surface abrasion Knife gate valve plug valve
Precise flow control small opening vibration control valve, V-ball valve
Leakage free, such as gas unreliable bi-directional sealing metal hard seal ball valve, gate valve
By comparing the characteristics of valves, leakage, failure or shortened life due to poor selection can be avoided to a minimum.