A stepped-pipeline feasibility worksheet helps a project team screen alternatives before detailed design. It records what is known, what is assumed and which evidence is still needed, without turning an early estimate into a capacity guarantee.
For a positive-pressure roots blower project, the worksheet has one practical purpose: identify whether a single-bore line appears adequate, whether stepped pipe deserves detailed evaluation or whether the required pressure is likely to fall outside the standard blower concept.
Section 1: State the Decision and Data Quality
Begin with the business decision. Is the project comparing routes, preparing a budget, checking an existing blower or creating an RFQ? The acceptable level of uncertainty differs for each purpose.
List the available inputs and label them measured, tested, supplier-provided or assumed. Required entries include material grade, solids rate, approximate route, vertical lift, bend count, feeder concept, receiver condition, inlet-air environment and operating schedule. Missing minimum-velocity or material-behaviour data should be visible rather than buried inside a margin.
Section 2: Create the Single-Bore Reference
Select one or more plausible internal diameters and estimate the inlet airflow needed for stable transport. Map the expected velocity rise and complete a preliminary pressure allocation for air piping, feeder leakage, straight route, elevation, bends and receiver filter.
Use ranges when inputs are uncertain. A low, expected and high-resistance case is more informative than one precise-looking answer. If all credible cases remain within acceptable velocity and roots blower limits, a stepped option may not deserve further effort.
Section 3: Record the Staging Trigger
If the single-bore reference shows excessive downstream velocity, identify the consequence. Possible triggers include product attrition, bend wear, noise, receiver impact or air-only pressure loss. State the location and operating case in which it occurs.
The trigger becomes the acceptance objective for the stepped alternative. Without a defined objective, the project cannot later prove that the added pipe transition delivered value.
Section 4: Screen One-Step Alternatives
Start with one downstream enlargement. Use actual internal diameters from available standard pipe sizes and test several potential transition regions. Reject any option that creates inadequate post-step velocity, requires an impractical transition location or performs poorly at turndown.
Only consider additional stages if one enlargement cannot keep the full route within the verified range. The worksheet should favour minimum complexity and should identify where detailed pressure modeling or material testing is required.
Section 5: Test Purge Feasibility
Prepare a separate clearing case with material feed stopped. Estimate the lower pressure and reduced downstream gas expansion. Check whether the largest bore retains enough velocity and whether the receiver filter can handle the purge airflow.
If the concept cannot clear reliably, do not assume that a longer timer will solve it. Flag the need for a revised bore, control sequence or representative test.
Section 6: Apply the Product-Scope Gate
Compare normal and maximum credible airflow-pressure points with the intended roots blower class and then with the selected model’s continuous operating data. A portfolio range is not a per-model guarantee, so mark the result “potentially feasible” until that check is complete.
If the predicted duty exceeds the verified roots blower range, list route, bore or material-rate changes for evaluation. Do not relabel a high-pressure compressor concept as a roots blower duty.
Section 7: Define the Next Evidence
The worksheet should finish with required actions: representative material trial, final route survey, feeder leakage test, filter data, detailed velocity map or selected-model review. Assign an owner and decision date for each item.
Glossary
Budget-stage estimate: Preliminary result used for project screening and cost planning rather than final procurement.
Candidate arrangement: Pipeline concept retained for further analysis but not yet technically approved.
Feasibility worksheet: Structured record used to compare early alternatives, uncertainty and required evidence.
High-resistance case: Credible preliminary scenario using upper expected pressure-loss inputs.
Reject criterion: Defined condition that removes an alternative from further consideration.
Screening range: Interval of plausible preliminary results reflecting uncertainty in early inputs.
Staging trigger: Measured or predicted problem that a stepped pipeline is intended to solve.