Cushion restriction

Cylinder Cushion Needle and Orifice Flow Calculator

Estimate compressible air flow through a cushion needle or equivalent orifice using diameter, pressure ratio, temperature, and discharge coefficient. Enter the application values to calculate four decision-ready outputs and review the governing assumptions before selecting equipment.

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Cushion restriction

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Engineering visual

Cushion Orifice Flow Calculator calculation path

Upstream pressure drives flow through the valve restriction to downstream pressure. The restriction and pressure drop are shown at the component where they occur.

01Equivalent orifice diameter
02Calculate and compare
03Estimated standard flow

Estimated standard flow

Estimated flow in SCFM

Equivalent orifice area

Absolute downstream/upstream ratio

Calculation reference

What this tool checks.

Use the displayed relationship to understand how the entered conditions affect the result. Treat the output as a preliminary selection, then verify actual operating conditions, catalog limits, and safety margin.

Inputs

Equivalent orifice diameter
Upstream gauge pressure
Downstream gauge pressure
Air temperature
Discharge coefficient

Outputs

Estimated standard flow
Estimated flow in SCFM
Equivalent orifice area
Absolute downstream/upstream ratio

Engineering guide

Use the result with the right context.

Calculate cushion orifice flow calculator for a pneumatic application and compare the result with supplier data.

Calculation workflow

Enter Equivalent orifice diameter, Upstream gauge pressure, Downstream gauge pressure and replace every default with application data.
Run the calculation while keeping pressure, temperature, geometry, and reference states consistent.
Interpret Estimated standard flow, Estimated flow in SCFM, Equivalent orifice area against the supplier datasheet, machine risk, and an appropriate design margin.

Assumptions and limits

Air is treated as an ideal gas and the entered coefficient or geometry must match the supplier's stated reference conditions.
Confirm the entire flow path, including tubing, fittings, manifolds, silencers, and simultaneous valve demand.

How to use the Cushion Orifice Flow Calculator

Start with measured or supplier-confirmed values for Equivalent orifice diameter, Upstream gauge pressure, Downstream gauge pressure, Air temperature. The calculator updates all outputs together, making it easier to see which assumption controls the preliminary selection.

What the result means

Estimated standard flow, Estimated flow in SCFM, Equivalent orifice area, Absolute downstream/upstream ratio answer different parts of the same engineering question. Use the primary result for selection, the secondary values to audit units and margins, and the visible formula to reproduce the calculation in an RFQ worksheet.

Engineering limits

Air is treated as an ideal gas and the entered coefficient or geometry must match the supplier's stated reference conditions. Confirm the entire flow path, including tubing, fittings, manifolds, silencers, and simultaneous valve demand. Final approval requires the current manufacturer datasheet and validation under installed conditions.

FAQ

Common review questions.

01Tool noteWhat does the Cushion Orifice Flow Calculator calculate?

Estimate compressible air flow through a cushion needle or equivalent orifice using diameter, pressure ratio, temperature, and discharge coefficient. It returns Estimated standard flow, Estimated flow in SCFM, Equivalent orifice area, Absolute downstream/upstream ratio so the primary answer and its supporting checks stay together.

02Tool noteCan I use the result as a final component selection?

Use it for preliminary engineering and RFQ comparison. Final selection must include supplier ratings, installation losses, transient conditions, applicable standards, machine risk, and validation testing.

03Tool noteWhy can a supplier calculation differ?

Supplier tools may use proprietary test curves, correction factors, rounding, leakage allowances, or reference conditions. Match those conditions and replace the defaults before comparing results.

04Tool noteWhat should I verify after using the Cushion Orifice Flow Calculator?

Check the entered units and reference conditions, then compare the calculated outputs with manufacturer ratings, application safety margins, transient loads, installation losses, and measured machine performance.