When Not To Use A Butterfly Valve?

Butterfly valve is widely used in various applications because of its simple structure, fast opening and closing speed and low cost. However, their performance limitations may make them unsuitable for certain working conditions. The following are the main reasons why butterfly valves are not recommended. Please combine technical details with practical information:
1.Extremely High Sealing Requirements
High-pressure gas or Liquid Pipelines
Reason: The The sealing of butterfly valve depends on the fit between disc and valve seat. Under high pressure, the seal can easily deform, leading to leaks. In particular, soft-sealed butterfly valves (such as rubber seals) accelerate aging due to prolonged high-pressure shocks.
For example, long-distance natural gas pipelines (with a pressure greater than 4 MPa) usually use ball valves or gate valves because of their low metal-to-metal sealing leakage rate.
Alternatives: Metal sealing ball valve, gate valves or globe valves.
Highly Toxic or Flammable Media Pipelines
Reason: Even a small leak from a butterfly valve can pose a safety hazard. For example, zero-leakage valves are required for media such as chlorine and hydrofluoric acid.
For example, a chemical company banned butterfly valves in chlorine gas pipes, requiring bellows to besealed with globe valves or diaphragm valves. Alternatives: Bellows-sealed valves, diaphragm or double seal ball valves.
2. High or Extremely low operating conditions
High-Temperature Environments (>425°C)
The reason: common butterfly valves sealing material (such as rubber, PTFE) in high temperature soften or decompose, resulting in seal failure. Even with hard-sealed butterfly valves, the metal sealing surfaces can leak at high temperatures due to differences in thermal expansion coefficients.
For example, the main steam pipeline (temperature 540°C) of a thermal power plant usually uses gate valves or globe valves whose metal sealing structures that is more heat resistant.
Alternatives: High temperature gate valve, globe valves or specially designed metal hard seal butterfly valves (temperature resistance must be verified).
Extremely Low-Temperature Environments (<-40°C)
Reason: At low temperature, the material becomes brittle and the butterfly valve body or disc may crack. In addition, sealing materials,such as rubber, lose their elasticity at low temperatures, leading to leakage.
For example, special cryogenic valves, such as cryogenic ball valves or gate valves, are required for the outlet pipeline of liquefied natural gas (LNG) storage tank (temperature -162°C). Alternatives: Cryogenic ball valves, gate valves or butterfly valves with insulation jackets (cryoperformance must be rigorously verified).
III. Scenarios requiring precise Precise Flow Control
Low flow or Fine-Tuning Requirements
Reason: butterfly valve flow characteristic are about the same, resulting in lower adjustment accuracy than globe valve or adjustment valve. Flow control is unstable, especially in small openings (e.g., <20%).
For example, the laboratory precision instrument supply system requires a needle valve or regulator to achieve accurate flow control of 0.1 L/min.
Alternatives: Interceptor, Regulator or needle valves.
High-Viscosity Media Pipelines
Reason: High-viscosity media (such as asphalt and heavy oil) can easily accumulate in the gap between the butterfly valve and valve seat, causing opening and closing blockages or seal failure.
For example: Refinery heavy oil pipelines usually uses gate valves or ball valves, its direct flow path design reduces the carry-over of media.
Valve of choice: gate valve, ball valves or rotary valve (e.g. valve used with cam rotor pumps). Media containing solid particles or fibres
a medium prone to scaling or abrasion
The reason: solid particles (such as sand, coal dust) or fibers (such as paper pulp) can accelerate wear and tear of butterfly valve seals, leading to leaks. In addition, particles can linger between the disc and seat, affecting opening and closing.
For example, butterfly valves in mine tailings pipelines are prohibited. Wear resistant or knife gate valves is required.
Alternatives: wear-resistant gate valves, knife gate valve or stopper gate valve.
Frequent opening and closing conditions
Reason: butterfly valve valve disc in the frequent opening and closing process easy to friction with the valve seat, leading to the sealing surface wear, shortening service life.
For example: a sewage treatment plant's inlet pump and outlet valve often open and close, usually using wear-resistant ball valve or gate valve.
Alternatives: wear-resistant ball valves, gate valves or pneumatic diaphragm control valves (if required). Installation space is limited or vertical
Vertical Installation
Reason: butterfly butterfly valve deadweight will lead to uneven pressure on the sealing surface, especially when installed vertically. The combined pressure of the medium and the weight of the disc can easily lead to leakage.
Example: Butterfly are generally avoided in vertical plumbing of fire water supply systems in high-rise buildings. Preferably a gate valve or globe valves.
Optional valve: gate valve, globe valves or elevator check valves (for unidirectional flow).
the Piping System Severe Vibration
Reason: vibration can cause butterfly valve bolts to loosen, or lead to the sealing surface dislocation, leading to leakage.
For example, because compressor outlet pipe vibrates a lot, usually use gate valves or ball valves with good vibration resistance.
Alternatives: Vibration-resistant gate valves, ball valves or valves with shock absorbers.
6. Other Special Scenarios
Emergencies requiring Rapid Shutoff
Reason: Although butterfly valves open and close relatively quickly, ball valves or gate valves close more quickly (especially if pneumatic or electric actuators are used). Case: Chemical plant Emergency shutoff valves must be closed within 1 second, usually using ball valves or specialized emergency shutoff valves.
Optional valves: ball valve, emergency shutoff valves or stopper valve.
The medium is corrosive and requires long-term use.
Reason: butterfly valve body and sealing material can not withstand strong corrosive media (such as concentrated sulfuric acid, aqua regia, etc.), resulting in corrosion or seal failure.
Case in point: The outlet valve of a chemical plant chemical plant sulfuric acid storage tank requires a fluorine-lined ball valve or diaphragm valve, which is more corrosion resistance than a standard butterfly valves.
Alternatives: Fluorine-lined ball valves, diaphragm valves, or Hastelloy valves.