How to read the specifications of a sanitary butterfly valve? Key points regarding butterfly valve operation, materials, and pipeline applications.

Sanitary piping is commonly used in food, beverage, dairy, pharmaceutical, biotechnology, and cosmetic manufacturing equipment. These pipelines not only need to stably transport liquids but also must be clean, leak-proof, corrosion-resistant, and easy to maintain. Therefore, valve selection cannot be based solely on whether the diameter matches the specifications; it is also crucial to verify the butterfly valve's dimensions, material, connection standards, and actual operating conditions.

Butterfly valves are characterized by their simple structure, small size, fast opening and closing speed, and intuitive operation, and are commonly used for opening, closing, and isolating fluids in pipelines. However, even among butterfly valves, there can be significant differences between general industrial butterfly valves and sanitary butterfly valves in terms of materials, surfaces, seals, and end connections.

This article will start by outlining the structure, product specifications, materials, and valve seats of sanitary butterfly valves to help equipment manufacturers, purchasing personnel, and engineering units grasp the key points for selection.

1. What are the differences between sanitary butterfly valves and ordinary butterfly valves?

Sanitary butterfly valves and general industrial butterfly valves operate on similar principles. Both are driven by a handle, actuator, or other operating device to rotate the valve stem, which in turn controls the rotation of the butterfly plate to open, close, or adjust the flow path.

The real difference between the two lies primarily in their application environment. General industrial butterfly valves are mostly used in cooling water, sewage, air conditioning, chemical, and general process pipelines; sanitary butterfly valves, on the other hand, place greater emphasis on the cleanliness of the pipeline interior, fluid contact materials, dead zone control, seal selection, and end connection methods.

What is a sanitary butterfly valve?

A sanitary butterfly valve is a fluid control element used in sanitary piping systems. It mainly consists of a valve body, a butterfly plate, a valve stem, a valve seat, a handle, and end connection structures. The butterfly plate is located in the center of the pipeline, and its rotation changes the fluid flow area.

When the butterfly plate is nearly parallel to the pipeline, the flow path is usually open; when the butterfly plate rotates to nearly perpendicular to the pipeline, it blocks the flow. Most butterfly valves are switched on and off in about a quarter turn, making them quick to operate and suitable for pipelines requiring frequent control or periodic isolation of equipment.

Sanitary butterfly valves typically use stainless steel as the main metal component, paired with a valve seat material suitable for fluid contact. Whether a product meets specific food, pharmaceutical, or hygiene standards still needs to be confirmed based on actual material certifications, processing specifications, and equipment requirements; it cannot be judged solely by the product name.

Which piping systems are suitable for sanitary butterfly valves?

Sanitary butterfly valves are suitable for sanitary pipelines that require control, isolation, and switching of fluids. Due to their relatively simple structure and intuitive disassembly and maintenance, they are commonly found in production lines, conveying equipment, mixing tanks, storage tank outlets, and cleaning pipelines.

Common applications include:

Food processing equipment

Food processing equipment may convey syrups, sauces, seasonings, cooking oils, water, or other liquid ingredients. When selecting a butterfly valve, in addition to considering the fluid viscosity and temperature, it is also important to consider whether residues are easily left behind and whether the cleaning method will affect the valve seat.

Beverage delivery pipeline

Beverage manufacturing processes often involve pure water, fruit juice, tea, sugar syrup, and other liquids. Butterfly valves can be used for switching, isolating, and cleaning between equipment sections, but it is necessary to confirm that the valve body, disc, and seat are suitable for the actual medium.

Dairy equipment

Dairy products are susceptible to changes in temperature and cleanliness, therefore, piping components must prioritize sealing integrity, ease of cleaning, and the materials used in fluid contact. Sanitary butterfly valves are commonly used in piping systems for raw materials such as milk, whey, and yogurt, and in related processes.

Pharmaceutical equipment

Pharmaceutical equipment may handle pure water, process fluids, solvents, or pharmaceutical solutions. In addition to butterfly valve specifications, it is usually necessary to confirm material certifications, cleaning methods, surface requirements, and batch management conditions.

Biotechnology process

Fluid conditions in biotechnology processes vary considerably and may include culture media, pure water, cleaning solutions, and other process media. When selecting a fluid, the complete fluid name, concentration, temperature, and operating frequency should be provided.

Clean fluid pipeline

In fluid systems where the risk of contamination, residue, or cross-contamination needs to be reduced, sanitary butterfly valves can serve as pipeline isolation and flow direction control elements, but their actual configuration still needs to be coordinated with the overall pipeline design.

Cosmetic manufacturing equipment

Emulsions, serums, and cleansing solutions have significantly different viscosities from liquid raw materials. If the fluid is viscous, attention should be paid to the butterfly valve's switching torque, flow channel residue, and cleaning method.

General sanitary piping system

Sanitary butterfly valves may be used to control pipelines containing clean water, pure water, food ingredients, and clean process liquids. Before purchasing, confirmation should be made based on the actual medium, pressure, and standards.

II. What items need to be confirmed for the specifications of sanitary butterfly valves?

Butterfly valve specifications are not just about product dimensions. A complete selection typically includes pipe diameter, working pressure, operating temperature, connection type, valve body material, butterfly plate material, valve seat material, and butterfly valve on/off method.

If any one of these aspects is incorrectly identified, problems such as installation failure, poor sealing, excessive switching resistance, or material incompatibility may occur. Therefore, before purchasing, a complete set of pipeline conditions should be prepared, and then the product specifications should be compared.

How do the size ranges of butterfly valves correspond to different pipelines?

The size of the butterfly valve must match the actual pipe specifications. When selecting a model, you should not only look at the nominal size such as one inch, two inches or three inches, but also confirm which standard the pipe uses and whether the product is designed based on the pipe's inner diameter or outer diameter system.

Different countries and industries may use different sanitary piping standards. Even if the dimensions are the same, the outer diameter, wall thickness, or end dimensions of the pipe may differ. Therefore, it is recommended to provide the following information before purchasing sanitary butterfly valves:

• Pipeline nominal dimensions
• Actual outer diameter of the pipe
• Pipe wall thickness
• Existing end form
• Piping adopts standard

Bueno Group sanitary butterfly valves are available in sizes from 1" to 6" and are suitable for imperial pipe diameter systems. However, during actual procurement, it is still necessary to confirm compatibility with the site's piping dimensions and connection standards.

How to determine the maximum and recommended work pressure?

Operating pressure is an important specification for butterfly valves. The maximum operating pressure indicated on the product usually represents the upper limit of pressure under specific temperature and conditions; the recommended operating pressure is closer to the reference range for stable daily operation.

The product information for Bueno Group sanitary butterfly valves is as follows:

• Maximum operating pressure: 10 bar (20℃)
• Recommended work stress: 6 bar (20℃)

This does not mean that all temperatures, fluids, and operating conditions can maintain the same pressure for extended periods. Actual tolerance conditions may be affected by factors such as increased temperature, valve seat aging, corrosive fluids, or transient pressure in the pipeline.

Therefore, when selecting a model, it is recommended to provide the normal operating pressure, maximum operating pressure, and whether instantaneous pressure exists. If the equipment frequently starts and stops, pumps switch rapidly, or valves close quickly, water hammer and pressure shock should also be evaluated.

Does operating temperature affect butterfly valve specifications?

Operating temperature affects the valve body, disc, seat, and overall sealing performance. Metal materials typically have a certain degree of temperature resistance, but valve seats may soften, expand, age, or lose their original elasticity due to increased temperature.

The typical temperature range for Bueno Group sanitary butterfly valves is:

• -10℃～+95℃

This information should be considered as a general operating condition reference. If the pipeline will use high-temperature hot water, steam, low-temperature liquids, or undergo frequent temperature cycles, it is still necessary to further confirm whether the valve seat material is compatible with the actual operating conditions.

The cleaning temperature should not be ignored. Some equipment operates at a low temperature during normal production, but high-temperature water or cleaning solutions are used during cleaning. In this case, the actual conditions that the valves are subjected to may be higher than during normal production.

What materials and connection standards need to be confirmed before purchasing?

In addition to size, pressure, and temperature, the following items should also be confirmed for sanitary butterfly valve specifications:

• Valve body material
• Material of butterfly plate and valve stem
• Valve seat material
• Handle material
• Pipeline Standards
• End connection type
• Operation method
• Is an actuator needed?

Bueno Group sanitary butterfly valves adhere to the following standards and specifications:

• ISO 2037
• BS 4825-1
• AS 1528-1

The standard end connection is a butt weld with an imperial tube outer diameter. If other sanitary end connections are used on site, it can be confirmed whether the corresponding specifications can be provided upon request.

Recommended product: Bueno Group sanitary butterfly valve

Bueno Group sanitary butterfly valves are suitable for control and isolation in piping systems. They are operated with a horizontal handle and have pre-drilled actuator mounting holes, allowing for further evaluation and configuration based on automation control requirements.

The main specifications are summarized as follows:

For product information, please refer to:

https://www.buenoeco.com/sanitary-butterfly-valve

3. How to determine the material specifications of a sanitary butterfly valve?

The material of a sanitary butterfly valve directly affects its corrosion resistance, cleanability, sealing performance, and service life. Different parts perform different functions, so they do not necessarily use the same material.

The valve body needs to support the pipeline and internal structure, the butterfly plate needs to directly contact the fluid and control the opening and closing, the valve stem is responsible for transmitting torque, and the valve seat is responsible for forming a seal. If the material of any one of these parts is unsuitable for the medium, the entire butterfly valve may still fail prematurely.

What are the advantages of the ASTM A182-F316L valve body?

Bueno Group sanitary butterfly valves feature bodies made of ASTM A182-F316L stainless steel. 316L stainless steel offers excellent corrosion resistance, and its low carbon content helps reduce the risk of corrosion in the weld heat-affected zone, making it commonly used in sanitary fittings, food processing equipment, pharmaceutical equipment, and chemical piping.

The main functions of the valve body include:

• Withstand pipeline pressure
• Fixed valve seat and internal parts
• Provide end connection
• Maintain the position of the disc and valve stem
• Protect the internal sealing structure

However, 316L does not mean it is suitable for all chemical media. If the fluid contains high concentrations of chloride ions, special acids, or high-temperature corrosive media, material compatibility still needs to be confirmed.

What environments are ASTM A351/CF8M disc valves and stems suitable for?

The product's disc and stem are made of ASTM A351/CF8M. CF8M is a common cast stainless steel material with a composition similar to 316 series stainless steel, possessing good corrosion resistance and mechanical properties.

The disc is located directly in the flow channel and is responsible for changing the fluid flow area. The valve stem transmits the torque from the handle or actuator to the disc. Therefore, in addition to being corrosion-resistant, these two components must also maintain sufficient strength and dimensional stability.

If the surface of the butterfly plate is affected by corrosion, scratches, or deposits, it may cause poor valve seat sealing; if the valve stem is misaligned or worn, it may cause the butterfly valve to not open or close smoothly or the butterfly plate to be in an abnormal position.

Materials and main functions of each component

Material specifications can only serve as a basis for selection; the final decision must be made based on the fluid, cleaning method, pressure, and temperature. In particular, the valve seat directly affects sealing and operating torque, making it a critical component that cannot be overlooked during selection.

IV. How does the white silicone valve seat affect the butterfly valve seal?

The valve seat is a crucial sealing component in sanitary butterfly valves. When the butterfly plate rotates to the closed position, its outer edge contacts and compresses against the valve seat, creating a fluid barrier. The condition of the valve seat directly affects whether the butterfly valve can open and close smoothly, and whether internal leakage will occur after closure.

Bueno Group sanitary butterfly valves use white silicone seats and meet FDA material requirements. Silicone has good elasticity and a certain degree of temperature adaptability, and is commonly used in sealing parts of food, beverage, and hygiene equipment.

How does the valve seat form a seal?

When the butterfly plate is closed, the valve seat needs to evenly cover the outer edge of the butterfly plate. If the valve seat has good elasticity, is the correct size, and is installed in the correct position, a seal can be formed between the butterfly plate and the valve body.

If the valve seat is too hard, the switching torque of the butterfly valve may increase; if the valve seat is too soft or has been compressed for a long time, permanent deformation may occur, resulting in a decrease in sealing force. If the valve seat size is inaccurate, the butterfly plate may also get stuck or fail to close completely.

Does the valve seat affect the switching resistance of a butterfly valve?

When a butterfly valve is opened or closed, the butterfly plate remains in continuous contact with the valve seat, and the friction between them affects the operating resistance. A new valve seat may initially feel tight, but the friction may gradually change after a period of operation.

If a butterfly valve suddenly becomes difficult to operate, possible reasons include:

• Valve seat aging or swelling
• Fluid residue drying
• The cleaning agent is incompatible with the valve seat.
• Foreign matter adhering to the surface of the butterfly plate
• Valve stem offset
• Long period of time without being turned on or off
• Excessive operating pressure

Do not force the switch with excessive force, as this may damage the handle, notch plate, valve stem, or valve seat. If the operating resistance is abnormal, stop the machine and check it first.

Do fluids and cleaning methods affect silicone valve seats?

Yes. Whether silicone is suitable for use depends on the actual medium, concentration, temperature, and contact time. Certain oils, solvents, acids, alkalis, or high-temperature cleaning conditions may cause the valve seat to swell, harden, crack, or lose its elasticity.

Recommendations to be provided before selection:

• Full name of fluid
• fluid concentration
• Normal operating temperature
• Maximum operating temperature
• Types of cleaning fluids
• Cleaning temperature
• Cleaning time
• Whether to perform steam or high-temperature sterilization

If the valve seat needs to withstand frequent cleaning and temperature cycling, its surface, elasticity, and sealing condition should be checked regularly.

How often should the valve seat be replaced?

There is no fixed replacement cycle for sanitary butterfly valve seats applicable to all equipment. Service life is affected by the frequency of butterfly valve operation, pressure, temperature, fluid type, cleaning method, and installation conditions.

If any of the following conditions are found, disassembly and inspection should be performed:

• Fluid continues to flow even after the circuit is closed.
• The resistance to switching the butterfly valve increased significantly.
• Cracks appeared in the valve seat
• Valve seat surface wear
• Valve seat swelling or deformation
• The butterfly plate cannot be fully closed.
• Residue remains after cleaning
• The sealing test failed.

Establishing regular maintenance records is a better indicator of the actual condition of equipment than simply replacing parts based on time.

V. What information is required before purchasing a sanitary butterfly valve?

The most common problem in butterfly valve selection is that only the diameter is provided, without specifying the piping standards and usage conditions. Even if the dimensions seem the same, different pipe outer diameters, end connections, and operating environments may still prevent the product from being installed or used.

6. Need to confirm the butterfly valve specifications and switching method? Please feel free to consult our professional selection advisors.

Looking for sanitary butterfly valves for food, beverage, dairy, pharmaceutical, biotechnology, or cleanroom applications? Bueno Group can help you determine the right product specifications based on your pipeline size, outer diameter standard, working pressure, operating temperature, fluid type, cleaning method, and butterfly valve switching requirements.

Product sizes range from 1" to 6", featuring stainless steel valve bodies, discs, and stems, paired with FDA-compliant white silicone seats. Standard sizes include imperial pipe butt-welded ends, and other sanitary end connections and actuator configurations can be evaluated upon request.

We welcome you to provide piping diagrams, dimensions, media, temperature, pressure, and operational requirements to contact Bueno Group immediately for sanitary butterfly valve selection advice that better suits your equipment and process conditions.