To control the flows of the working fluid, a special part is used, which is called the spring cap. With its help, the streams of the working fluid enter and exit directly from the cylinder. The spring cap is a round product with a small diameter rod. The transition between the cap and the rod provides for a large radius. This is necessary to increase aerodynamics and strength.

1. A8 (4D2, 4D8)
2. A8 Saloon (4D2, 4D8)
3. A8 / S8 (4D2, 4D8)
4. A4 (8D2, B5)
5. A4 Saloon (8D2, B5)
6. A4 / S4 (8D2, B5)
7. A4 Avant (8D5, B5)
8. PASSAT (3B2)
9. PASSAT Saloon (3B2)
10. A6 (4B2, C5)
11. A6 Saloon (4B2, C5)
12. A6 / S6 (4B2, C5)
13. PASSAT Variant (3B5)
14. PASSAT Wagon (3B5)
15. PASSAT Estate (3B5)
16. A6 Avant (4B5, C5)
17. A6 / S6 Avant (4B5, C5)
18. PASSAT (3B3)
19. PASSAT Saloon (3B3)
20. PASSAT Variant (3B6)
21. See more in applications

The operation of the spring cap

When the valve rotates around its own axis, holding the gas during landing, the poppet allows gases to pass through. There is a gap between the rod and the bushing. It allows you to prevent jamming when overheating. This clearance helps the poppet to fit into the seat. Due to the presence of a chamfer installed at an angle, self-alignment of the product is supported. In addition, the locking force is increased.

The material of the spring cap

Today, the FEBI BILSTEIN brand Spring Cap are made of silchromic steel. It is a highly durable material with a high level of fire resistance. It is used for diesel engines as well as for claim motors. New generation parts are used from a different type of steel. It will not work for diesel engines. After all, sulfur, which is part of diesel fuel, systematically destroys steel, which contains nickel.