Stage results
Cylinder detail
Sensitivity: open each pocket 0.50 in from where it is now
How to read it. In the series train the outlet pressure is held by the pipeline, so every pocket change re-balances the interstage pressures until all five stages pass the same gas. Opening a pocket on one stage lowers that stage's capacity, drops its suction pressure, raises the ratio on the stage before it, and moves rod load and discharge temperature on both. The sensitivity table shows that chain for each throw.
Model. Volumetric efficiency 0.95 − clearance × (r1/n·Zs/Zd − 1) on flange pressures, n = 1.28; valve losses scale with gas velocity squared; BHP = 1.17 × polytropic on internal pressures; rod loads from internal pressures on 16.75 / 11.5 / 8.0 / 7.0 in bores and a 1.5 in rod; 1 % suction and 2.5 % discharge bottle losses. Matches the four Ariel sheets within about 3 % on flow and BHP, 5 % on throw 1. Throw 4 pocket slope is estimated (no second data point on the sheets). Use it to decide which pocket to touch and roughly how far; confirm the final setting against an Ariel run before you change a setpoint.