Understanding Air Pressure for Inflatable Parks

Why "Pressure" Causes Confusion in Inspections
In real operations, the word "pressure" can mean two different things. Many inspection disputes happen when these two are mixed together:
1) Blower static pressure capability (equipment specification)
2) Inflatable internal operating pressure (what a manometer reads inside the unit)

They are not the same number.

Key Terms (Plain English)

• Airflow (CFM / m³/h): How much air the blower can move. In inflatables, airflow mainly compensates leakage and keeps the structure firm under dynamic patron load.
• Static pressure (Pa / psi): A measure of the blower's ability to push air against resistance. Higher static pressure capability helps maintain shape when the system has restriction/leakage paths.
• Internal operating pressure (Pa / psi): The actual cushion pressure inside the inflatable during operation. This is what you measure with a manometer at a proper static test point inside a chamber.

Continuous-Air vs. Sealed-Air (Closed-Air) Products
Commercial inflatable amusement devices are typically continuous-air systems: the blower runs continuously to maintain firmness. Sealed-air (closed-air) products are inflated to a target range and then sealed; the operator monitors internal pressure and tops up as needed per manufacturer limits.
Operational takeaway:
• Continuous-air products depend on blower airflow + blower static capability.
• Sealed-air products depend on a manufacturer-defined internal pressure operating range and routine pressure checks.

What an ASTM-Style Information Plate Should Specify
For ASTM-style plates used on inflatable amusement devices, the clearest practice is to specify the REQUIRED INFLATION EQUIPMENT (number of blowers + minimum equivalent blower performance). This prevents undersized blowers from being substituted in the field.
Recommended plate wording structure:
• No. blowers required (e.g., 3)
• Blower power (e.g., 2 HP / 1500 W each)
• Minimum volume flow per blower (CFM and/or m³/s)
• Minimum static pressure capability per blower (Pa and/or psi)
• PLUS: add a short 'Inspector Note' in the manual clarifying that internal operating pressure (manometer) does not have to equal blower static capability.

The Most Common Mistake: Assuming Pressures Add Up (They Don't)
Static pressure is not additive like "3 blowers × 0.31 psi = 0.93 psi." Multiple blowers mainly increase available airflow and allow multi-zone feeding. The inflatable's stabilized internal pressure is set by leakage, relief paths, fabric elasticity, and load-not by summing blower 'psi' values.

Case Study (Des Plaines in the USA): What to Write vs. What You Measure
Factory configuration
• Model: DP01
• Blowers supplied: 3 pcs × 1500 W (2 HP) continuous-air blowers
Manufacturer-required minimum inflation equipment (equivalent performance):

What a manometer reading means:
• A manometer measures internal operating pressure at the measurement point.
• Internal operating pressure typically reads lower than the blower's static capability because the system is flowing and leaking by design.
• A field reading like 1183 Pa (0.172 psi) can be normal if measured at a proper static point and the unit is fully inflated and stable.

How to Measure Internal Pressure Correctly (Operations Checklist)
Use this quick checklist to get defensible readings for inspectors:
1) Use an appropriate low-pressure gauge (digital manometer or Magnehelic) with sufficient resolution.
2) Measure at a true static point inside a chamber (stable wall area), not at vents, zippers, mesh openings, or directly at the blower outlet.
3) Insert the probe through a sealed tap (seal around the probe so you don't create leakage).
4) Orient the probe to avoid dynamic airflow effects (do not point the opening into a jet).
5) Record: blower model/quantity, voltage, extension cord length, patron load at time of measurement, and measurement location.

Inspector Note
The value 2150 Pa (0.31 psi) referenced in the manual/plate is the blower's minimum static pressure capability (equipment specification), not the inflatable's internal operating (cushion) pressure. In normal operation the inflatable has continuous airflow and controlled leakage, so the measured internal chamber static pressure using a manometer will typically be lower than the blower's static capability. Therefore a manometer reading such as 1183 Pa (0.172 psi) can be correct and acceptable when taken at a proper static test point inside the chamber, provided the unit remains fully inflated, stable, and firm under the rated patron load.

Can Operators Reduce Airflow During Light Use?
In practice, new products with low patron load can appear 'over-firm' at full blower output. Operators may reduce airflow only if the unit remains fully inflated, maintains shape, and has no soft zones. Any reduction should be done using an approved method (e.g., blower speed control where permitted) and must never allow under-inflation.

Summary
• Blower static pressure capability (Pa/psi) is an equipment specification; it should be shown on the ASTM-style plate as a minimum blower capability.
• Internal operating pressure (manometer) is a field reading; it is typically lower and depends on where/how you measure.

If you are sourcing a commercial inflatable park, indoor inflatable park, inflatable obstacle course, or inflatable slides for shopping malls or FECs, contact us for professional support for both products and operation.