A request for an air-knife blower often contains a desired pressure and airflow but omits where those values were measured, which knives were active, and whether the product passed its drying test. Without that context, a supplier cannot tell a process requirement from a catalogue endpoint. This checklist is for collecting evidence before a recommendation; it does not calculate the blower size.
State the Process Result First
Record the product, material or surface being treated, line speed, product width and the acceptance condition. Note whether the task is water removal, debris removal or cooling. Photograph the product position and mark persistent wet or weak-air zones. State the incoming condition as well as the acceptable outlet condition, because a pressure reading cannot prove that the process works.
Identify the Air-Knife Arrangement
Give each knife or nozzle an identifier. For each, record the effective slot length, setting or gap, feed location, angle, working distance and the product surface it serves. Include a simple layout showing the blower, filter, main pipe, branches, manifold and terminals. Mark which devices operate together in each normal production mode. Do not infer total demand by adding unrelated brochure maximums.
Record Pressure With Its Location and Operating State
A pressure value on its own is unusable without a tapping point and production state. Label readings at the blower outlet and knife plenum or branch inlet, where safe and practicable. Record whether each number is gauge or differential pressure, the instrument used, filter condition, open valves, active knives and blower speed or command. Note the pressure drop across an inlet filter or suspect accessory if it is available.
A higher outlet reading can coexist with inadequate air at the product. Keep pressure and airflow evidence from the same steady operating condition; never pair a pressure taken with outlets closed with a flow taken during full production.
Describe Airflow Evidence and Its Limits
Record any direct airflow measurement with its method, units and measurement location. If only outlet velocity is available, note the measurement positions and effective open area; do not present a single velocity reading as a verified total flow. Where no reliable flow test exists, write “not measured” and provide the air-knife supplier’s flow-versus-pressure data at the installed gap, if available. A transparent unknown is more useful than a precise-looking guess.
Capture Modes, Electrical Conditions and Constraints
For each relevant production mode, record active outlets, line speed, accepted process result, blower setting, voltage, current and measured real input power where available. Include normal and demanding credible modes, not an impossible combination of every worst case. Add ambient conditions, space limits, available supply, control interface and connection dimensions. Technical and electrical limits must come from the installed nameplate and final manual rather than assumed family data.
Send a Reproducible Evidence Pack
The supplier handoff should contain the layout, knife schedule, pressure and airflow records, instrument locations, product acceptance criterion, operating modes, electrical details and photographs. Label missing data explicitly. Ask the supplier to state which assumptions remain open and to show a proposed simultaneous pressure–airflow point on the exact model curve. Acceptance and commissioning measurements should later use the same named conditions.
For calculation of one blower serving several knives, use the separate multi-knife sizing article. For nozzle placement and coverage, use the nozzle-layout article. This page owns the evidence-collection step before those engineering decisions.
Next Step
Send Towwind the evidence pack and request a duty-point review that identifies missing measurements before any model is recommended.
Frequently Asked Questions
Can a motor rating replace an air-knife airflow measurement?
No. Rated motor power does not establish airflow at the installed pressure and knife setting.
Is blower outlet pressure enough for a quotation?
No. State its measurement location and the corresponding process and airflow condition. Include the knife-plenum reading where available.
What if the air-knife supplier has no flow curve?
Mark the flow basis as unverified and request a controlled test or supplier data before final selection.