Why price nitrogen per part?

Because every alternative is priced that way. The decision is never 'nitrogen or nothing'. It is nitrogen against a stronger lamp, a different photoinitiator, a surface-active initiator, or accepting a tacky surface, and those are compared per part or per year. An hourly gas figure cannot be set against any of them without being converted first, so this page does the conversion.

What sets the curtain flow?

Leakage, far more than chemistry. The oxygen level needed comes from the formulation, but the flow required to hold it comes from how well the zone is sealed. Baffles, brush seals, a longer entry tunnel and a smaller open aperture all reduce consumption permanently, and that is nearly always a better investment than a larger gas contract.

Can I turn the nitrogen off between runs?

Usually, and it saves roughly in proportion, but not exactly. A purged zone refills with air when the flow stops, and bringing it back down takes time and gas, so the first parts after a restart can run at a higher oxygen level than the process assumes. Many installations keep a low maintenance flow for exactly that reason, which is a smaller saving than full gating and a more reliable one.

Is nitrogen or more irradiance the better answer?

It depends on the shape of the costs, and the point of the annual row is to let you compare them. Inerting is a continuing cost; a lamp upgrade or a photoinitiator change is mostly one-off. Where the annual gas bill is a meaningful fraction of a lamp upgrade, the upgrade usually wins over any reasonable horizon, and it also removes the asphyxiation hazard, which does not appear as a number anywhere on this page.

Does this include the generator or the tank?

No. This prices delivered gas only. An on-site generator replaces a per-unit price with capital plus electricity plus maintenance, which changes the economics substantially at high consumption. Amortise it into a per-scf figure before entering it here, or the comparison will flatter whichever option you have not yet costed properly.

What about the safety of an inerted zone?

It is the first question, not a footnote to the cost. Nitrogen displaces breathable air, and an inerted tunnel or enclosure can be an oxygen-deficient atmosphere that gives no warning at all before it incapacitates someone. Oxygen monitoring, ventilation, interlocks and confined-space procedures belong to that assessment, and none of it is a line item this page can price.

UV Curing calculator

UV Nitrogen Consumption Calculator: Cost per Part and per Year

Price a nitrogen inerting curtain in units that can be compared with the alternatives. Enter the curtain flow, the fraction of the hour it runs, the delivered gas price and the parts produced. The calculator returns cost per part, hourly and annual cost, and the gas consumed per part. Nitrogen exists on a UV line to beat oxygen inhibition, and every alternative route to the same result, more peak irradiance, a different photoinitiator, a surface-active initiator, accepting the defect, is priced per part or per year. An hourly gas figure cannot be set against any of them.

What this calculator does

Price a nitrogen inerting curtain per part and per year, so it can be compared with the alternative ways of beating oxygen inhibition.
Use it for comparing nitrogen inerting against a lamp upgrade, annualising a gas cost for a capital case, quantifying what gating the curtain with the lamp saves, showing what a leaky cure zone costs in gas, putting inerting onto a per-part cost model.
Price a nitrogen inerting curtain per part and per year, so it can be compared with the alternative ways of beating oxygen inhibition.

Formula used

Hourly consumption (scf/hr) = curtain flow × lamp-on fraction
Hourly cost = hourly consumption × delivered price
Nitrogen cost per part = hourly cost ÷ parts per hour
Nitrogen per part (scf) = hourly consumption ÷ parts per hour
Annual cost = hourly cost × 2000 operating hours (250 shifts × 8 hr: a disclosed convention)

Inputs explained

Nitrogen curtain flow rate: Delivered flow at the curtain while inerting. Set by the oxygen level the chemistry needs and by how well the zone is sealed, not by the lamp.
UV lamp on-time fraction per hour: Fraction of the hour the curtain actually flows. Only counts as a saving if the nitrogen is genuinely shut off between runs.
Delivered nitrogen price: All-in delivered cost including cylinder or tank rental, vaporiser energy and delivery, or the amortised cost of an on-site generator.
Parts cured per hour: Production rate through the inerted zone. Converts a gas bill into a figure comparable with every other per-part cost in this category.

How to use the result

Best suited to comparing nitrogen inerting against a lamp upgrade, annualising a gas cost for a capital case, quantifying what gating the curtain with the lamp saves, showing what a leaky cure zone costs in gas, putting inerting onto a per-part cost model.
Prices the gas only. Regulators, piping, curtain hardware, oxygen monitoring and the capital of an on-site generator are all excluded. Says nothing about whether the flow achieves the oxygen level the chemistry needs, that is measured with an oxygen analyser in the zone, not calculated from flow. Ignores purge time after an interruption, which reduces the saving from gating the flow. Excludes the asphyxiation hazard entirely. An inerted zone displaces breathable air and needs monitoring, ventilation and confined-space discipline; that is a safety matter, not a cost line. Cannot compare nitrogen with the alternatives on effectiveness, only on cost.

Common questions

Why price nitrogen per part? Because every alternative is priced that way. The decision is never 'nitrogen or nothing'. It is nitrogen against a stronger lamp, a different photoinitiator, a surface-active initiator, or accepting a tacky surface, and those are compared per part or per year. An hourly gas figure cannot be set against any of them without being converted first, so this page does the conversion.
What sets the curtain flow? Leakage, far more than chemistry. The oxygen level needed comes from the formulation, but the flow required to hold it comes from how well the zone is sealed. Baffles, brush seals, a longer entry tunnel and a smaller open aperture all reduce consumption permanently, and that is nearly always a better investment than a larger gas contract.
Can I turn the nitrogen off between runs? Usually, and it saves roughly in proportion, but not exactly. A purged zone refills with air when the flow stops, and bringing it back down takes time and gas, so the first parts after a restart can run at a higher oxygen level than the process assumes. Many installations keep a low maintenance flow for exactly that reason, which is a smaller saving than full gating and a more reliable one.
Is nitrogen or more irradiance the better answer? It depends on the shape of the costs, and the point of the annual row is to let you compare them. Inerting is a continuing cost; a lamp upgrade or a photoinitiator change is mostly one-off. Where the annual gas bill is a meaningful fraction of a lamp upgrade, the upgrade usually wins over any reasonable horizon, and it also removes the asphyxiation hazard, which does not appear as a number anywhere on this page.
Does this include the generator or the tank? No. This prices delivered gas only. An on-site generator replaces a per-unit price with capital plus electricity plus maintenance, which changes the economics substantially at high consumption. Amortise it into a per-scf figure before entering it here, or the comparison will flatter whichever option you have not yet costed properly.

Last reviewed 2026-08-25.