Does this predict pneumatic response time from port diameter?

No. Port diameter alone does not define compressible valve, tubing, exhaust and cylinder dynamics.

Can I enter NL/min or SCFM?

No. The flow route requires actual volumetric flow at the powered chamber state and representative operating point.

Is valve switching delay included?

No. The result is piston motion time only; command, sensor, valve, pressure-build-up and settling delays are separate.

Documented kinematics — not pneumatic response prediction

Documented Pneumatic-Cylinder Stroke Kinematics

Calculate piston motion time from a controlled mean piston speed or actual local powered-chamber volumetric flow. Port diameter, supply pressure and load are not converted into a fabricated response time.

t=L/vQactual=A·vActual flow onlyMotion time only

Controlled input route

Motion

Controlled bore diameter

Controlled rod diameter

Controlled piston stroke length

Documented route value

Controlled operating-point source

The rate represents the same powered chamber, motion and stroke interval as the geometry. A speed value is a documented mean piston speed over that interval. A flow value is actual volumetric inflow at the chamber state, not NL/min, ANR, SCFM or free-air delivery. The Q/A route assumes negligible leakage/storage/deformation over the interval. Command, sensing, valve switching, pressure build-up, breakaway, acceleration, cushioning, impact and settling delays are excluded.

Documented piston motion time

—

Mean piston speed

—

Actual powered-chamber flow

—

Powered chamber area

—

Swept chamber volume

—

Kinematic arithmetic only.

Acap=πD²/4; Aann=π(D²−d²)/4; V=A·L
speed route: t=L/v and Qactual=A·v
flow route: v=Qactual/A and t=V/Qactual

D is controlled bore diameter, d is rod diameter, L is piston stroke, A is the powered chamber area, V is swept chamber volume, v is mean piston speed and Qactual is actual powered-chamber volumetric flow at the same operating state.

The two routes are algebraically equivalent continuity/kinematic statements. The University of Dayton course notes provide the general volumetric-flow/velocity continuity basis. They do not make this a pneumatic transient model.

Not response time. Total command-to-settle response includes controller/sensor delay, valve switching and conductance, compressible pressure build-up/exhaust, tubing dead volume and heat transfer, friction/breakaway, load acceleration, gravity/side load, leakage, cushioning, impact, rebound and settling. None is inferred from port diameter.

Why the old predictor was removed

The undocumented `QNL/s≈0.048·Aport·Pabs/10` was not verified.
Its subsequent fill equation cancelled Pabs, making stroke time independent of pressure once a crude force cutoff passed.
The declared Pavg and acceleration model were unused; load changed only a yes/no branch.
Tube volume incorrectly used port diameter as tube inside diameter.
A fixed10% friction estimate and generic speed ranges were unsourced.

Standards and manufacturer boundary

ISO 15552:2018 edition2,confirmed2025 establishes interchangeability dimensions for a specified detachable-mounting pneumatic-cylinder family;it does not define this kinematic relation or a universal response-time formula.SMC explicitly directs users to model-specific catalog data and shows that cylinder characteristics depend on model,bore and conditions.

NEEDS_LICENSED_SOURCE: selected cylinder/valve/tubing dynamic model; sonic/subsonic valve coefficients and reference conditions; chamber thermodynamics; friction/load/cushioning characteristics; switching/sensor delays and acceptance criteria.

Πηγές

University of Dayton continuity notes; ISO15552:2018 official record; SMC cylinder characteristics; NIST unit conversions.