Iso Vacuum Double Claw Clamp Design Features And Working Principle

A kf clamp for vacuum piping uses symmetrical claw arms to distribute clamping force around an ISO flange connection. The double-claw structure engages both flange sides, while a centering ring and O-ring maintain alignment and sealing. This arrangement provides balanced loading with a removable connection.

How the Double-Claw Structure Works

An ISO vacuum connection relies on axial compression between mating flange faces. The clamp transfers tightening force from its body to the flange through two opposing claws.

The double-claw configuration is designed for ISO flange connections. Listed construction options include SS304 and aluminum, with CNC machining and a surface finish of Ra≤0.8.

Force Distribution Through Two Claws

1. Symmetrical loading: Two claws apply force from opposite sides.
2. Flange engagement: Each claw grips the corresponding flange edge.
3. Axial compression: Tightening draws both flange faces together.
4. Seal positioning: The centering ring keeps the O-ring between the flanges.

The two-sided loading reduces the risk of uneven compression during assembly.

Why Symmetry Matters in Vacuum Service

A clamp iso connection must maintain even compression around the sealing interface. Flange tilt or uneven loading can reduce O-ring contact and create a vacuum leak path.

An iso clamp with two claws distributes mechanical force across the flange. The centering ring controls radial alignment, while the O-ring forms the elastomeric seal.

The sealing system consists of:

• Double claws: Transfer tightening force to both flange sides.
• Centering ring: Maintains concentric flange alignment.
• O-ring: Creates the vacuum seal.
• Flange faces: Provide the compression surfaces.

ISO-K and ISO-F Connection Logic

The listed specification includes large ISO vacuum flanges in ISO-K and ISO-F configurations. ISO-K uses clamp fasteners, while ISO-F uses nuts and bolts.

An iso k clamp is associated with ISO-K connections because the clamp supplies the external force required to join the flange pair. Clamp dimensions should match the flange geometry rather than nominal pipe size alone.

Material and Surface Finish

SS304 provides a corrosion-resistant stainless option, while aluminum can reduce assembly weight. Selection depends on vacuum conditions, mechanical load, temperature, and corrosion exposure.

The listed configuration supports silicone, Viton, and PTFE sealing materials. Seal selection should match the vacuum medium and operating temperature.

A smooth machined surface can also reduce contamination around the connection and support repeatable assembly.

Installation and Clamping Checks

A vacuum clamp requires correct alignment between the flange, centering ring, O-ring, and claws.

🔩 Flange alignment: Keep both flange faces concentric before tightening.

⭕ O-ring placement: Seat the O-ring evenly inside the centering ring.

⚖️ Claw engagement: Ensure both claws contact the flange edges correctly.

🔧 Tightening: Apply sufficient force without damaging the flange or seal.

After assembly, the connection should be checked with the applicable vacuum leak-test procedure.

Where Double-Claw Clamps Fit

The double-claw design suits vacuum chambers and process systems used in chemical, gas, petrochemical, electric power, metallurgy, medical, food, and pharmaceutical applications.

Its removable structure also allows access for inspection, seal replacement, and equipment modification without permanent welding.

Selecting the Right Configuration

A kf clamp should be selected according to flange standard, nominal size, vacuum level, seal material, temperature, and installation space.

1. Confirm ISO-K or ISO-F compatibility.
2. Match clamp size to flange dimensions.
3. Select SS304 or aluminum according to service conditions.
4. Choose the O-ring material for the vacuum environment.
5. Check claw engagement and centering-ring fit.
6. Perform a vacuum leak check after installation.

The double-claw structure applies force from two sides rather than concentrating it at a single point. Proper coordination of the claws, centering ring, O-ring, and flange faces supports stable sealing in a removable vacuum connection.

ISO Vacuum Double Claw Clamp

• These single and double clamps are used (in conjunction with a centering ring with fitted o-ring) for mating ISO flanges. The ISO flange (also called Large ISO) is used for HV chamber ports and is available in two distinct styles; ISO-K which uses clamp fasteners and ISO-F which uses nut and bolt fasteners.

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