Tier 4 ComplianceTier 4 compliance is an imporant issue for fleet owners. Elasto Proxy makes heat blankets for diesel engines used in off-road mobile equipment. This article is the first in a series about heat blankets and the Tier 4 emissions standard.

Heat blankets are used with diesel-powered equipment to promote engine performance and pollution control. To handle the high temperatures associated with diesel exhaust systems, they’re made with silicone-coated fiberglass fabric or other heat-resistant cloth. Heat blankets also use high-temperature thread made of Kevlar or fiberglass, and metal snaps that promote ease-of-installation.

Today, diesel equipment owners are using heat blankets as part of their efforts to achieve Tier 4 compliance. Established by the U.S. Environmental Protection Agency (EPA), Tier 4 is designed to reduce harmful exhaust from some diesel engines. Heat blankets alone can’t ensure your Tier 4 compliance, but they can help you to maximize pollution control technologies and minimize equipment downtime.

Diesel Engines and Heat Blankets

To understand why heat blankets matter, it helps to review how diesel engines work. First, cooler outside air enters the engine cylinders and is mixed with diesel fuel. Next, pistons compress this air-fuel mixture at high pressures. Finally, the mixture combusts and explosions generate heat. As a byproduct of the combustion process, exhaust gases and particulate matter (PM) are produced.

Within the diesel engine’s exhaust systems, hotter gases help to promote engine performance in the form of more power and better mileage. Before the days of Tier 4, that’s a big reason why heat blankets were used. In addition to directing thermal energy (heat) back into the exhaust system, heat blankets help engine cabins to stay cooler while limiting the spread of heat to nearby engine components.

When the gases with a diesel exhaust system are hotter, more pollutants are incinerated. Downstream, less PM reaches pollution control technologies (such as valves and filters) that can clog and fail in the field. When these pollution control systems stop working, diesel engines that were Tier 4 compliant require maintenance and incur costs. Lost productivity can be expensive, too.

Tier 4 Compliance and Diesel Engines

Tier 4The EPA’s Tier 4 standard is the latest in a series of increasingly-stringent requirements to reduce harmful exhaust from diesel engines. The Tier 1, 2, and 3 standards involved advanced engine designs, but Tier 4 requires new pollution control technologies. Ultimately, Tier 4 reduces two pollutants by about 90%. In addition to PM, Tier 4 slashes byproducts of diesel fuel combustion called nitrogen oxides (Nox).

Now that the 2008 to 2015 phase-in period for Tier 4 is over, diesel engine manufacturers are producing powerplants that meet the stricter EPA requirements. Tier 4 doesn’t affect all diesel engines, however. Rather, Tier 4 applies only to diesel powerplants that meet all of the following criteria:


Non-road / off-road

8 kW (11 hp) to 560 kW (750 hp) and up

Tier 4 and Diesel-Powered Equipment

In terms of application examples then, Tier 4 applies to the diesel-powered equipment such as backhoe loaders, bulldozers, diesel lawn tractors, excavators, farm tractors, and forklifts. The diesel engines in new logging equipment, portable generators, skid steer loaders, and wheel loaders must also meet Tier 4 requirements for emissions reduction.

That’s not all, however. Tier 4 also applies to diesel locomotives, marine vessels, and underground mining equipment. Stationary diesel-powered generators are covered, too, along with many other types of construction, agricultural, and forestry equipment. Although different emissions standards govern the engines used in on-road vehicles and airplanes, Tier 4 affects large parts of the mobile equipment market.

Preview: Heat Blankets and Tier 4 Compliance

In Part 2 of this series from Elasto Proxy, we’ll take a closer look at how heat blankets support the use of pollution control technologies in the Tier 4 standard. We’ll also examine why, compared to metal plates and foil, heat blankets are an effective way to maximize pollution control and minimize equipment downtime. Until then, please contact us with your questions about heat blankets.

Contact Us

Close Menu