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Air Rotary Union for CNC Pneumatic Clamping Fixtures

CNC rotary fixtures and indexing tables need reliable compressed air transfer for clamping, unclamping, pressure holding, and blow-off. Begapunk helps match passage count, flange layout, bore size, and RPM for machining automation.

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Application Fit

Keep clamping pressure stable while the fixture rotates

Who this is for: CNC machine tool builders, fixture designers, and manufacturing engineers integrating pneumatic clamping into rotary tables and machining centers.

When a CNC fixture rotates, its compressed-air lines must not twist or pull on the actuator. A pneumatic rotary union provides sealed rotating passages for compressed air between the stationary air-supply side and the rotating fixture.

The most common design mistake is choosing by outside diameter only. Engineers should confirm pressure, flow, passage count, rotational speed, mounting face, and how the hose load will be supported.

BP-2P-130-0001 air rotary union for a CNC pneumatic clamping fixtureInstalled productBP-2P-130-0001 used in a customer's low-speed circular-saw fixture.
Customer Production Application

BP-2P-130-0001 in a Custom CNC Circular-Saw Fixture

This customer-authorized video frame shows BP-2P-130-0001 installed at the rear of a custom CNC machining fixture on a circular-blade saw machine. The customer uses two independent compressed-air passages for fixture clamp and release.

Rear view of a custom CNC circular-saw fixture with BP-2P-130-0001 installed
Customer-authorized production-video frame showing the rear of the custom fixture; the customer and machine brand are not disclosed.

Application details

Equipment
Customer's custom CNC machining fixture on a circular-blade saw machine
Installed rotary union
BP-2P-130-0001
Pneumatic function
Two independent compressed-air passages for fixture clamp and release
Operating context
Low-speed customer production equipment; the exact rotational speed is not established by the video
Camera view
Rear or tail of the fixture; the front jaws are outside the frame
Disclosure
Customer identity and machine brand are not disclosed
View BP-2P-130-0001 Discuss a Similar Fixture

Typical CNC Pneumatic Clamping Rotary Union Specs

  • Pressure: 0.4–0.8 MPa (clamping); confirm the continuous-duty limit for the selected model against the current product page, approved drawing, medium, temperature, and machining cycle
  • RPM: <200 (most fixtures) / up to 500 (high-speed rotary tables)
  • Passages: 1–4 (clamp + unclamp + blow-off + coolant mist)
  • Media: dry air + water-soluble coolant — seal must resist both
  • Mounting: flange mount preferred for fixture plate integration
  • Bore: 6–10 mm for standard clamps; 16–30 mm for large fixture plates
  • Seal: Glyd Ring (PTFE composite) recommended for coolant compatibility
Engineering Points

CNC Fixture Selection Checklist

Pressure holding

Clamping pressure must remain stable during indexing and machining. Leakage can affect part positioning and process repeatability.

Passage separation

  • Clamp
  • Unclamp
  • Blow-off
  • Sensor or auxiliary air

Mechanical interface

Check flange bolt pattern, shaft bore, anti-rotation support, and whether the rotary joint is exposed to chips or coolant mist.

Selection Table

CNC Pneumatic Clamping Rotary Union Parameters

Fixture AreaCommon FunctionSelection FocusPossible Model or Configuration
Rotary table centerCompressed air to rotating fixtureFlange mounting, pressure stability, hose supportBP-2P or BP-3P family
Large fixture plateMultiple clamps and blow-offMore passages, larger bore, low leakageBP-4P or custom multi-passage
Compact indexing jigSingle clamp or release lineSmall size, threaded connection, easy installationBP-1P or BP-2P compact model
Suggested Models

Recommended Starting Points

BP-2P-16-0001Large bore, flange mount, useful for fixture integration.BP-2P-30-000130 mm bore option for larger rotating fixtures.BP-4P-30-0001Four-passage model for multi-function pneumatic fixtures.

Need help selecting a CNC fixture rotary union?

Send whatever you already have—a fixture drawing, photo, air-circuit sketch, or the operating details you know. We will recommend a suitable catalog model or custom interface and tell you if anything else is needed.

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FAQ

CNC Fixture Questions

Can a rotary union hold clamping pressure during machining?

Yes, if the model is correctly selected for pressure, seal condition, and hose loading. The fixture circuit should also include suitable pressure control.

Can Begapunk match a fixture drawing?

Yes. For CNC fixtures, drawings are strongly recommended because mounting dimensions and port location usually decide the final model.

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