How do you calculate leak test capacity per shift?

Multiply assemblies per cycle by usable cycles per shift to get gross capacity, then multiply by station uptime and first-pass yield. With 4 assemblies/cycle x 48 cycles = 192 gross, then x 90% uptime x 97% yield, you get 167.6 good leak-tested assemblies per shift.

What is the difference between gross capacity and good leak-tested output?

Gross capacity (192/shift here) is the theoretical maximum if the booth never stopped and nothing leaked. Good output (167.6/shift) subtracts the 19.2 assemblies lost to downtime and 5.2 lost to leak rejects, so it reflects what you can actually ship.

What is a good first-pass leak test yield for brazed coils?

Mature brazed aluminum and copper-tube coil lines typically run 95-99% first-pass at the leak booth. The 97% default leaves about 5 reject assemblies per shift in this example; below 93%, braze joint or expansion-tooling problems usually deserve a containment review before the test station gets blamed.

Why is the leak test station usually the bottleneck?

Pressure-decay and helium tests need evacuation, stabilization and dwell time that cannot be rushed without losing sensitivity, so each cycle is fixed at tens of seconds to minutes. Upstream fin-stacking and brazing are faster, which is why the booth caps line throughput.

How do I increase good leak-tested output?

You have three levers: raise batch size per cycle (multi-up fixtures), add usable cycles (faster evacuation or a second test head), or attack the losses. Recovering the 19.2 downtime assemblies through better fixture changeover usually pays back faster than chasing the last point of yield.

Does this calculator account for retest of leakers?

No. It treats first-pass yield as final good output. If you rework and retest borderline assemblies, your shippable count rises, but so does effective cycle time, which reduces usable cycles per shift. Model retest separately rather than inflating the yield figure.

Heat Exchanger, Coil & Radiator Manufacturing calculator

Leak Test Capacity Calculator

Leak test capacity tells you how many heat exchanger coils, radiators or condenser assemblies your leak test station can actually pass per shift after accounting for downtime and rejects. On a brazed or mechanically expanded coil line, the helium or pressure-decay leak booth is almost always the production bottleneck, so its throughput sets the ceiling for the whole cell. Process engineers and production planners use this number to schedule shifts, size buffer racks ahead of the booth, and decide whether a second test fixture is justified. Because it separates gross capacity from good output, it also exposes how much hidden capacity you lose to leakers and station stoppages.

What this calculator does

Estimate good leak-tested heat exchanger assemblies per shift from test fixtures, cycles, station uptime, and first-pass leak test yield.
Use it when helium, air decay, pressure decay, dunk, or mass spectrometer leak testing limits coil, radiator, condenser, or oil cooler shipments.
It computes good leak-tested assemblies per shift by multiplying batch size and available cycles into gross capacity, then derating for station uptime and first-pass leak test yield.

Formula used

Gross leak test capacity = assemblies tested per cycle × usable leak test cycles
Good leak-tested output = gross capacity × station uptime × first-pass leak test yield

Inputs explained

Assemblies leak-tested per pressure-decay cycle:
Usable leak test cycles per shift:
Leak test station uptime:
First-pass leak test yield:

How to use the result

Use it when planning shift output, sizing the leak test booth against upstream braze or fin-pack rates, or building a business case for additional test fixtures.
It assumes a steady cycle time and a single stable yield; real shifts mix product families with different fill, dwell and evacuation times, so validate the cycles-per-shift input against actual booth logs.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).

Common questions

How do you calculate leak test capacity per shift? Multiply assemblies per cycle by usable cycles per shift to get gross capacity, then multiply by station uptime and first-pass yield. With 4 assemblies/cycle x 48 cycles = 192 gross, then x 90% uptime x 97% yield, you get 167.6 good leak-tested assemblies per shift.
What is the difference between gross capacity and good leak-tested output? Gross capacity (192/shift here) is the theoretical maximum if the booth never stopped and nothing leaked. Good output (167.6/shift) subtracts the 19.2 assemblies lost to downtime and 5.2 lost to leak rejects, so it reflects what you can actually ship.
What is a good first-pass leak test yield for brazed coils? Mature brazed aluminum and copper-tube coil lines typically run 95-99% first-pass at the leak booth. The 97% default leaves about 5 reject assemblies per shift in this example; below 93%, braze joint or expansion-tooling problems usually deserve a containment review before the test station gets blamed.
Why is the leak test station usually the bottleneck? Pressure-decay and helium tests need evacuation, stabilization and dwell time that cannot be rushed without losing sensitivity, so each cycle is fixed at tens of seconds to minutes. Upstream fin-stacking and brazing are faster, which is why the booth caps line throughput.
How do I increase good leak-tested output? You have three levers: raise batch size per cycle (multi-up fixtures), add usable cycles (faster evacuation or a second test head), or attack the losses. Recovering the 19.2 downtime assemblies through better fixture changeover usually pays back faster than chasing the last point of yield.

Last reviewed 2026-05-12.