P22.45 and P22.50 are both found in current market nomenclature for continuous press chain replacement work. The pitch difference is only 0.05 mm per pitch, but a continuous press uses long chain paths, so replacement should never be based on a rounded pitch assumption.
Cumulative error matters
Small pitch variation repeated over many links becomes a measurable length difference. That is why replacement projects should define pitch-control and cumulative-length requirements, especially for paired or synchronized chains.
Compare the full interface
Measure plate profile, roller and pin geometry, retaining details, sprocket engagement and the installed chain path. Do not assume the rest of the geometry is identical because two chains have nearly the same nominal pitch.
Use an approved drawing as the release point
For obsolete or undocumented chains, a supplier can develop a replacement proposal from a sample, but production should begin only after the critical dimensions and the customer-approved drawing are frozen.