Why measure at three locations?

Two segments distinguish upstream supply loss from the blast-machine and hose segment, making corrective action more specific. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.

Can nozzle pressure be inferred from receiver pressure?

No. Restrictions and airflow demand can create substantial loss under load. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.

What does the productivity index mean?

It applies the cited rule of thumb only to pressure shortfall from the entered target and is explicitly a planning indicator. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.

Does low loss prove enough compressor capacity?

No. Capacity must also be checked against total airflow demand and reserve. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.

Why must the readings be taken under load?

Most restrictions reveal themselves only when air is flowing. Static pressures can equalize across undersized hose, dirty filters and restrictive fittings, making the system look healthy. Simultaneous loaded readings show the pressure energy actually lost while the nozzle is consuming air and allow the segment comparison to mean something.

Does pressure loss per 100 feet prove the hose is undersized?

Not by itself. The downstream segment includes the pot, valves, couplings and nozzle as well as hose friction. The normalized value is a comparison signal. Confirm hose inside diameter, fitting condition, valve position and airflow with a detailed pressure-drop analysis before specifying replacement hardware.

Abrasive Blasting, Shot Peening & Surface Prep calculator

Loaded Abrasive Blast Air Pressure Loss Calculator

Locate pressure loss in a blast-air system using four readings: compressor discharge under load, blast-pot inlet under load, nozzle pressure while blasting and blast-hose length. The calculator separates upstream distribution loss from downstream pot, valve and hose loss, reports total loss and normalizes the downstream drop per 100 feet. This makes it easier to decide where an inspection should begin instead of blaming the compressor for every low-pressure condition. Required nozzle pressure and reference airflow are documented assumptions; the calculation is a diagnostic screen and does not replace a flow test or component-specific pressure-drop model.

What this calculator does

Localize loaded pressure loss between compressor, blast-pot inlet, and nozzle while separating total system loss from target shortfall.
Use it for pressure-loss troubleshooting, hose-layout comparison, compressor-capacity verification, troubleshooting a blast line that reaches static pressure but loses pressure when the nozzle opens..
Localize loaded pressure loss between compressor, blast-pot inlet, and nozzle while separating total system loss from target shortfall.

Formula used

Pressure loss is separated into compressor-to-pot and pot-to-nozzle drops, with hose-normalized loss and a fixed required-nozzle baseline.
Fixed secondary assumptions compiled into this release: Required nozzle pressure: 100 psi; Loaded airflow (context only): 200 cfm.

Inputs explained

Compressor receiver pressure while loaded: Receiver or supply-manifold pressure during steady blasting.
Blast-pot inlet pressure while loaded: Pressure immediately upstream of the blast machine during flow.
Nozzle pressure while loaded: Pressure measured at the nozzle using the approved method while blasting.
Pot-to-nozzle hose length: Actual developed blast-hose length represented by the pressure readings.

How to use the result

Best suited to pressure-loss troubleshooting, hose-layout comparison, compressor-capacity verification, troubleshooting a blast line that reaches static pressure but loses pressure when the nozzle opens..
The four-input result is conditional on the disclosed fixed assumptions; use a detailed engineering model when they are not representative. Does not calculate pipe friction from geometry. Does not replace hose, coupling, valve, or compressor sizing. The productivity index is not a contractual guarantee. The model cannot distinguish friction, elevation, valve restriction, leakage or transient compressor control without additional measurements.

Common questions

Why measure at three locations? Two segments distinguish upstream supply loss from the blast-machine and hose segment, making corrective action more specific. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.
Can nozzle pressure be inferred from receiver pressure? No. Restrictions and airflow demand can create substantial loss under load. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.
What does the productivity index mean? It applies the cited rule of thumb only to pressure shortfall from the entered target and is explicitly a planning indicator. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.
Does low loss prove enough compressor capacity? No. Capacity must also be checked against total airflow demand and reserve. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.
Why must the readings be taken under load? Most restrictions reveal themselves only when air is flowing. Static pressures can equalize across undersized hose, dirty filters and restrictive fittings, making the system look healthy. Simultaneous loaded readings show the pressure energy actually lost while the nozzle is consuming air and allow the segment comparison to mean something.

Last reviewed 2026-08-24.