Kalrez® perfluoroelastomer parts: a high performance solution for heavy-duty diesel engine sealing
The heavy-duty diesel truck market is moving strongly to engine turbocharging to meet lower emission and higher fuel efficiency goals. Hotter engines, longer warranties, more aggressive fluids, increased use of biodiesel fuels, and stringent new emissions regulations all demand higher performance materials to seal turbocharger systems.
Seals used in heavy duty ship and locomotive diesel engines also face very hostile operating environments combining high temperatures and aggressive chemicals, like sulfuric acid, which can test elastomer seals to the limits.
While seals play a vital role in fluid and gas containment, seal failure can result in very costly repair and standstill time while engines are out of action.
DuPont Performance Elastomers (DPE) Kalrez® perfluoroelastomer parts can meet the challenge by significantly reducing the cost of standstills, and by increasing safety and reliability. Kalrez® O-rings can provide a durable turbo sealing solution, offering lifetime service at temperatures as high as 327°C, comfortably above the typical 230°C+ air and air/fuel mix temperatures found inside the turbo chamber.
In addition, Kalrez® perfluoroelastomer parts offer excellent resistance to the additives in engine oils, including chemicals, dispersants, oxidation and abrasion inhibitors, and to sulfuric acid in exhaust gases. They also meet the most stringent evaporative emissions regulations and offer permeation resistance 10 times greater than fluoroelastomer.
Perfluoroelastomer is the most temperature and chemical resistant of all the elastomers - enabling Kalrez® perfluoroelastomer parts to withstand more than 1 800 chemicals and solvents, including acids, bases, amines and steam, and retain their elasticity and recovery properties even after long-term exposure to temperatures up to 327°C. DPE offers Kalrez® in almost any custom shape such as O-rings, valve seats, diaphragms and gaskets.
Kalrez® perfluoroelastomer parts perform equally well in diesel engines for marine and locomotive use, particularly in exhaust manifold and turbo system sealing.
Kalrez® 7075, a high temperature resistant perfluoroelastomer with excellent compression set resistance, has recently been tested under intensive operating conditions by a major diesel rail drive engine manufacturer, with positive results. Early indications are that Kalrez® perfluoroelastomer engine sealing parts will allow operators to reduce maintenance costs significantly.
For further information about Kalrez® parts in diesel engine sealing, contact CTC.DPE@usa.dupont.com