The ISO flange connected high vacuum butterfly valve is a compact quarter-turn isolation valve engineered for vacuum pipelines, process chambers and gas-handling systems where reliable shut-off, low internal volume and standardized flange interfaces are essential. Manufactured by Trekre Valve, this high vacuum butterfly valve combines a disc-type closure element with ISO-compatible flange connections, enabling direct integration into vacuum equipment skids, semiconductor process lines, coating systems, laboratory vacuum networks and industrial degassing circuits without custom adapter hardware.
Vacuum technology operates at absolute pressures far below atmospheric conditions, typically from rough vacuum through high vacuum and into ultra-high vacuum ranges depending on the pumping train and chamber design. In these environments, every valve must minimize outgassing, maintain seal integrity across pressure differentials and provide predictable flow control when throttling or isolating process gases. The ISO flange connected butterfly valve addresses these requirements through a simple disc-and-seat geometry, tight flange mating surfaces and material selections matched to the working medium and temperature envelope.
ISO flange connected high vacuum butterfly valve construction
Connection type: ISO flange (clamp / caliper style compatible with JB/T 919 and GB/T 6070 vacuum flange standards)
Structure: concentric disc butterfly valve for vacuum service
Size range: 2″ to 12″ (DN50 to DN300), project-specific bore available
Working pressure range: 10⁵ Pa down to 1.3×10⁻⁵ Pa (published reference range; confirm the selected assembly’s documented operating limits)
Leak rate: ≤ 1.3×10⁻⁶ Pa·L/s (reference value; confirm against the selected valve’s test report)
Body material: stainless steel 304/316, carbon steel with surface treatment
Seat options: NBR, PTFE and fluoropolymer liners for temperature and media compatibility
Operation: manual handle, worm gear reducer, pneumatic or electric actuator
Medium temperature: -25°C to 80°C (NBR seat); -30°C to 150°C (PTFE seat)
Installation orientation: follow the approved drawing and instructions for the selected valve and actuator; torque and stem-seal loading checks alone do not establish suitability for every orientation.
Working principle and disc sealing mechanism
A vacuum butterfly valve consists of a valve body, stem, disc and resilient or fluoropolymer seat ring. The disc rotates through approximately 90 degrees about the stem axis, progressively opening or closing the flow passage. In the fully closed position the disc face compresses against the seat ring to form a gas-tight barrier between upstream and downstream vacuum zones. Because the disc presents a thin profile relative to gate or ball alternatives, the valve contributes minimal obstruction to conductance calculations and occupies less axial space in crowded vacuum manifolds.
Handle rotation provides quick on-off action suitable for operator-controlled isolation at chamber load locks, foreline branches and maintenance bypass lines. Worm gear operators reduce input torque on larger nominal sizes and support overhead or hard-to-reach installations common on vacuum coating equipment. Pneumatic and electric actuators extend remote control capability for automated process sequences, interlock systems and cleanroom environments where manual access is restricted.
ISO flange interface and pipeline integration
ISO flange connections standardize the bolt circle, gasket groove and clamp hardware used across vacuum components from pumps and chambers to valves and gauges. The ISO flange connected high vacuum butterfly valve mounts between two ISO-compatible flanges using quick-release clamp rings or bolted assemblies per the selected flange variant. This modular approach simplifies system assembly, reduces leak paths compared with threaded or welded joints on temporary setups and allows one-sided valve removal for seat inspection without disturbing the entire vacuum line.
Before installation, flange faces must be cleaned, free of machining debris and aligned within the tolerance specified for the clamp system. Gasket selection should match the flange standard and the expected bake-out temperature if the line undergoes thermal conditioning. Trekre Valve recommends verifying bolt or clamp torque in incremental steps to achieve uniform gasket compression without distorting the wafer-style valve body.
Vacuum performance and leakage control
Vacuum system performance depends on cumulative leakage from every component in the conductance path. The leak-rate figure of ≤ 1.3×10⁻⁶ Pa·L/s published on this page is reference information pending confirmation for the selected assembly. Request the product-specific test report identifying the test gas, method, temperature, pressure conditions and whether the reported leakage is through the seat or to atmosphere. Do not treat the listed vacuum range or leak rate as a guaranteed rating for every size, material or seal option. For ultra-high vacuum duties, material outgassing rates, stem seal design and bake-out procedures must be evaluated against the target base pressure.
NBR seats provide economical sealing on general industrial vacuum lines handling air, nitrogen and inert gases at moderate temperatures. PTFE seats extend chemical resistance and temperature capability for process gases encountered in semiconductor etch, chemical vapour deposition and pharmaceutical freeze-drying equipment. Stainless steel bodies resist corrosion from residual moisture or aggressive vapours during pump-down cycles, while carbon steel options with protective coatings suit cost-sensitive utility vacuum headers.
Typical applications across vacuum industries
Vacuum equipment manufacturers integrate ISO flange butterfly valves on foreline isolation for rotary vane and dry screw pumps, venting manifolds on vacuum drying ovens and bypass loops on roots blower stages. Semiconductor fabrication tools require repeatable isolation on rough and medium vacuum branches where fast cycle times and low particulate generation influence yield. Laboratory research installations use these valves on vacuum filtration skids, electron microscope antechambers and thin-film deposition systems where compact face-to-face dimensions simplify benchtop layouts.
Industrial production sectors including chemical processing, pharmaceutical manufacturing and food vacuum packaging employ high vacuum butterfly valves on degassing circuits, solvent recovery headers and pneumatic conveying isolation points. The quick-opening disc geometry supports applications requiring frequent switching, while the lightweight body reduces structural loading on suspended vacuum piping compared with heavier double-flanged alternatives on equivalent nominal bore.
Material selection and operating envelope
Body material selection should reflect the corrosivity of the process gas, cleaning agents used during maintenance and any exposure to atmospheric humidity during vent cycles. CF8 and CF8M stainless steel bodies address chloride-bearing atmospheres and corrosive vapours without additional linings. WCB carbon steel bodies offer structural economy on clean, dry air systems where external painting or epoxy coating provides adequate environmental protection.
Seat material must remain elastic or maintain sealing contact across the full temperature swing from ambient startup through steady-state operation. NBR suits applications up to approximately 80°C where hydrocarbon-compatible elastomers are acceptable. PTFE and related fluoropolymers handle higher temperatures and a broader chemical spectrum including aggressive solvents and halogenated gases common in specialty vacuum processes. Project engineers should confirm seat compatibility with the complete gas mixture, including trace contaminants and plasma by-products on semiconductor tools.
Installation, maintenance and service life
Correct installation begins with verifying flange standard, nominal size and orientation against the system isometric drawing. Follow the approved drawing and installation instructions for the selected valve and actuator; stem-seal and mounting-load checks alone do not establish suitability for every orientation. After assembly, a leak check using helium mass spectrometry or pressure rise testing confirms joint integrity before introducing process gases. Operating personnel should avoid slamming the disc against the seat at high differential pressure, which can accelerate seat wear and compromise long-term vacuum performance.
Routine maintenance includes inspecting the stem seal for wear, cleaning the disc and seat contact surfaces and confirming smooth rotation through the full stroke. Replaceable seat designs simplify field refurbishment without removing the valve body from the pipeline on many configurations. Periodic lubrication of the stem bearing and actuator interface preserves low operating torque across thousands of cycles on frequently switched isolation points.
Comparison with other vacuum valve types
Gate valves provide straight-through conductance with minimal pressure drop but require greater axial space and typically cost more on large bore vacuum headers. Ball valves offer full-port flow but introduce a larger internal cavity that can trap condensable vapours during pump-down. The ISO flange connected butterfly valve balances conductance, weight and cost for moderate vacuum isolation duties where quarter-turn operation and compact envelope are priorities. For ultra-high vacuum or high differential pressure across the closure member, triple-offset or specialized vacuum gate valves may be specified instead.
Selection checklist for procurement engineers
Confirm nominal bore, ISO flange standard, target vacuum range and allowable leak rate before ordering. State the process gas composition, design temperature, cycle frequency and required actuation method. Indicate any special requirements such as position indication, solenoid interlock, bake-out temperature limit or cleanroom packaging. Provide the pumping system schematic and expected operating pressure at the valve location so Trekre Valve engineering can verify seat material and body specification against the application.
Trekre Valve supports technical selection, actuator sizing and customized material configurations for vacuum system integrators and end users worldwide. Contact the Wuxi factory with complete operating data to receive a proposal aligned with JB/T 919, GB/T 6070 and project-specific vacuum valve datasheets.
Product parameters summary
Type: ISO flange connected high vacuum butterfly valve
End connection: ISO vacuum flange (JB/T 919, GB/T 6070 compatible)
Nominal diameter: DN50–DN300 (2″–12″)
Vacuum range: 10⁵ Pa to 1.3×10⁻⁵ Pa
Leak rate: ≤ 1.3×10⁻⁶ Pa·L/s
Body: stainless steel 304/316, carbon steel
Seat: NBR, PTFE
Temperature: -30°C to 150°C (seat dependent)
Operation: handle, worm gear, pneumatic, electric
Standards: JB/T 919, GB/T 6070, ISO flange vacuum interface
Frequently Asked Questions
Which ISO vacuum flange details should I include in my inquiry?
Identify the exact flange family, size, clamping or bolting arrangement and seal configuration used by the mating equipment. Ask for the selected drawing rather than assuming every ISO vacuum connection is interchangeable.
What vacuum information is needed to select the valve?
Provide the required absolute-pressure conditions, gas composition, temperature and leakage or cleanliness requirements. Request confirmation of the selected valve and seal performance; the high-vacuum name alone does not establish those limits.
Can this valve be used for vacuum throttling as well as isolation?
State the required control duty and ask for suitability of the actual disc, seat and operating arrangement. An isolation-valve description does not by itself confirm control performance over a particular vacuum range.