Staged filling schedule, rates, and hold times for tank hydrostatic testing (OISD-STD-129 §on Filling Rates/Filling Procedure)
◉ OISD-STD-129 STYLE CHECK · NOT A REGULATORY SUBMISSION TOOL
⚠ Indicative tool only. Rates, stage fractions, and hold times checked directly against the standard's page images. The 0.25 m/hour floating-roof cap applies specifically until the roof floats (a liquid depth this tool doesn't know, since it depends on the roof/seal's own buoyancy design) — shown as a separate note rather than merged into the staged schedule below. A written, site-specific filling procedure based on actual soil/foundation conditions should still govern; this is a planning aid, not a substitute for that engineering judgment.
Identification
Research entries stay private to you for practice/testing. Switch to Official once this is a real design your company should see.
Tank & Filling Basis
Up to 1.5 m/hour is cited for a stable foundation (rock or piled concrete slab) with no predicted settlement — use your own design basis if different.
Floating roof note (§Filling Rates): a low filling rate of not more than 0.25 m/hour should be used until the roof is floated; thereafter the rate may be increased to the design maximum. This tool can't determine the exact liquid depth at which your specific roof floats — plan the early filling phase accordingly.
Staged Filling Schedule
Stage filling rate = 70% of the design maximum rate, applied at each stage. Hold times default to the standard's stated minimums and are editable.
Stage
Fill To
Height (m)
Increment (m)
Fill Time (hr)
Hold Time (hr)
Result
Stage filling rate (70% of design rate)—
Total fill time (all stages)—
Total hold time (stages 1–3 + final)—
Total estimated procedure duration—
Settlement Monitoring Frequency (reference)
Shell level measurements: tank empty → 50% full → 67% full → 100% full → empty again, at minimum. Where significant settlement is predicted: take levels every 24 hours while filling to Stage 1, then every 12 hours (or more frequently, depending on observed settlement rate) during each subsequent filling stage and while holding at each stage, until the rate of settlement diminishes. Measure the bottom profile before filling starts and again near-empty (leaving ~0.25m of water) to establish total bottom settlement. See the existing Tank Settlement calculator for evaluating the readings themselves.