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Code of Federal Regulations Title 40. Protection of Environment § 40.90.329 Catalyst thermal stress test

Current as of January 02, 2025 | Updated by Findlaw Staff

(a) Oven characteristics. The oven used for thermally stressing the test catalyst must be capable of maintaining a temperature of 500 ±5 °C and 1000 ±10 °C.

(b) Evaluation gas composition.

(1) A synthetic exhaust gas mixture is used for evaluating the effect of thermal stress on catalyst conversion efficiency.

(2) The synthetic exhaust gas mixture must have the following composition:

Constituent

Volume percent

Parts per million

Carbon Monoxide

1

Oxygen

1.3

Carbon Dioxide

3.8

Water Vapor

10

Sulfur dioxide

20

Oxides of nitrogen

280

Hydrogen

3500

Hydrocarbon*

4000

Nitrogen = Balance

* Propylene/propane ratio = 2/1.

(c) Phase 2 engines. The catalyst thermal stress test is not required for engine families certified to the Phase 2 standards.

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Cite this article: FindLaw.com - Code of Federal Regulations Title 40. Protection of Environment § 40.90.329 Catalyst thermal stress test - last updated January 02, 2025 | https://codes.findlaw.com/cfr/title-40-protection-of-environment/cfr-sect-40-90-329/

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