{"id":5226,"date":"2020-02-17T08:51:34","date_gmt":"2020-02-17T06:51:34","guid":{"rendered":"https:\/\/blog.febi.com\/?p=5226"},"modified":"2020-02-17T08:51:35","modified_gmt":"2020-02-17T06:51:35","slug":"egr-valve-for-clean-air","status":"publish","type":"post","link":"https:\/\/blog.febi.com\/en\/egr-valve-for-clean-air\/","title":{"rendered":"EGR Valve: For Clean Air"},"content":{"rendered":"\n

Exhaust gas recirculation \u2013 or EGR for short \u2013 significantly\nreduces nitrogen oxide (NOx<\/sub>) emissions. The EGR valve controls the\nexact quantity of exhaust gases that are fed back into the intake manifold.\nThere, the exhaust gases displace part of the oxygen, therefore lowering the\ncombustion temperature. This prevents the formation of some nitrogen oxides.\nThis is particularly important for diesel engines. <\/p>\n\n\n\n

There are two main types of EGR valves. One is vacuum controlled\nand uses an electro-pneumatic pressure transducer. The opening and closing\nthereof is operated by the engine control unit. The other is driven by a DC\nelectric motor or stepper motor. Both electronic and vacuum variations are\nopened and closed subject to engine load. <\/p>\n\n\n\n

Vacuum Control<\/strong><\/h2>\n\n\n\n
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The electro-pneumatic pressure transducer uses a vacuum that\nis taken from the intake manifold or generated by a vacuum pump. This is\ncontrolled by pulse width modulation to regulate the position of the pneumatic\nvalve on the EGR valve; this regulates the amount of recirculated exhaust gas\nused by the engine. <\/p>\n\n\n\n

Electronic Control<\/strong><\/h2>\n\n\n\n

Here, the position of the EGR valve is controlled by the\nelectric EGR control valve. This results in a more accurate valve position,\nwhich is fed back to the engine control unit via a potentiometer. <\/p>\n\n\n\n

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Diesel engines use their EGR systems throughout their entire\nrev range, which can be up to 60% of the total intake at idle. This system also\nhelps to raise cylinder temperature during the initial warm-up \u2013 this reduces\nnoise significantly. <\/p>\n\n\n\n

Consequences of a Defect<\/strong><\/h2>\n\n\n\n

In diesel vehicles, the valves have large opening\ncross-sections due to the high recirculation rates. This can reduce the\nnitrogen oxide concentration by up to 50% and the formation of soot particles\nby approximately 10%. In gasoline engines, the cross-sections of the EGR valves\nare significantly smaller. <\/p>\n\n\n\n

Due to the constant use and harsh operating conditions, EGR modules are widely used. A defective EGR valve not only results in a significant increase in nitrogen oxides in the exhaust gas, but can also have a negative effect on the other components, such as the diesel particulate filter. febi offers a wide range of high-quality EGR valves, most of which contain the required seals. <\/p>\n