ENGINE VALVE Iran

DEUTZ engine engine valve

The DEUTZ diesel engine uses separate valve seats for intake and exhaust functions. Intake valve seats are manufactured from sintered iron alloy with 15 percent chromium. Exhaust valve seats contain molybdenum and nickel for high temperature resistance up to 750 degrees Celsius. The seat angle is precisely ground at 45 degrees with a tolerance of plus-minus 0.1 degree. Seat width measures 1.8 to 2.2 millimeters for intake valves. Exhaust seats have a wider contact surface of 2.5 to 3.0 millimeters. The interference fit between seat and cylinder head equals 0.08 to 0.12 millimeters. This press fit prevents loosening during thermal expansion cycles. Seat concentricity relative to the valve guide stays below 0.03 millimeters. Hardness of exhaust seats reaches 350 to 400 HB for wear resistance.

Valve guides in DEUTZ engines are made from phosphor bronze or gray cast iron with copper infiltration. Inner diameter of the guide measures 8.00 to 12.00 millimeters depending on engine series. The radial clearance between valve stem and guide equals 0.03 to 0.07 millimeters for intake valves. Exhaust valves require larger clearance of 0.05 to 0.09 millimeters due to higher thermal expansion. Guide length varies from 45 to 65 millimeters to ensure proper stem alignment. The installed heigh

Volvo loader L90 and L120 engine valve seat

The valve seat in Volvo L90 and L120 loader engines is manufactured from chromium-molybdenum alloy steel with a surface hardness of 60 to 64 HRC and thermal resistance up to 950°C. It is precisely interference-fitted into the cylinder head, and the valve contact angle is maintained between 45 and 46 degrees to ensure optimal sealing and gas flow efficiency. The inner diameter of the intake valve seat is 42 mm for L90 and 46 mm for L120, while the exhaust seat diameters are 36 mm and 40 mm respectively. The seat profile and throat geometry are engineered to minimize friction and distribute thermal loads uniformly, increasing durability and reducing heat-related engine failures.

In addition to high mechanical strength, the valve seat surface is coated with a nickel-chrome layer to resist oxidation and carbon buildup. Operating pressures at the valve-seat interface range from 1.5 to 2.5 bar, with resistance to repeated thermal shock from combustion cycles. The average service life exceeds 8,000 operating hours under heavy-duty conditions. Accurate seat concentricity and controlled interference fit reduce valve misalignment and leakage, ensuring stable compression, consistent combustion efficiency, and reliable performance under continuous high-load operation.

Volvo loader L90 and L120 engine valve

The intake and exhaust valves in Volvo L90 and L120 loader engines play a critical role in the combustion process, ensuring precise air-fuel mixture flow. These valves are made of heat- and wear-resistant steel, capable of withstanding operating temperatures between 650°C and 900°C. The intake valve diameter is 42 mm for L90 and 46 mm for L120, while exhaust valves measure 36 mm and 40 mm, respectively. Valve timing is set with millisecond precision, and camshaft angles are optimized to maximize airflow and exhaust gas evacuation, improving fuel efficiency and reducing engine emissions.

The valves operate under variable pressures ranging from 1.2 to 2.5 bar, with an average service life exceeding 8,000 operating hours. The valve seat and head are engineered to minimize friction and wear, reducing maintenance requirements. A lubrication system supplying 2.0 to 3.0 bar ensures proper cooling and smooth operation. Additionally, nickel-chrome coating enhances thermal fatigue resistance and corrosion protection, maintaining engine stability under heavy-duty conditions.

ENGINE VALVE

Engine valves are manufactured from high thermal strength chromium-silicon-manganese alloy steel. Their temperature tolerance reaches 850 degrees Celsius for exhaust and 750 degrees for intake valves. The standard stem diameter ranges from 5 to 10 mm with a dimensional tolerance of ±0.01 mm. The seat angle is typically 45 degrees with a surface finish better than Ra 0.4 microns. Valve spring force varies between 200 and 500 Newtons depending on engine design. These valves undergo gaseous nitriding heat treatment. This process increases surface hardness to up to 800 Vickers.

The valve structure comprises key sections: head, seat face, and stem. The valve lash is typically between 0.15 and 0.25 mm at ambient temperature. The design life under cyclic loading exceeds 100 million cycles. Modern valves often feature anti-wear coatings like chromium-carbide. These coatings reduce the friction coefficient by up to 40%. Hollow stem cooling in some designs lowers operating temperature by 100 degrees Celsius. This feature improves thermal efficiency by up to 3%.