Rod seal K29 90x105,5x6,3

The K29-090 PU is a two-piece single-acting buffer seal designed for hydraulic rod sealing applications. The K29 profile consists of a polyurethane (PU) sealing element and a thermoplastic back-up ring made of POM. The elastomeric element features a specially designed 20° contact angle profile that allows back pressure relief between the buffer seal and the primary seal. The POM back-up ring prevents extrusion of the sealing material under pressure.

The K29 is not intended as a primary sealing element — it is used exclusively as a buffer seal in combination with a primary rod seal (such as K22, K32 or equivalent profiles). Its function is to protect the primary seal from pressure peaks, reducing wear on the entire sealing system. The seal is assembled into closed grooves; before installation, the element should be lubricated with system oil.

This seal is a direct replacement for the following profiles from other manufacturers: Parker BU, Simrit SM, Trelleborg BF-R, SKF RBB, Hallite BUFFER 653, ARTIC SEALS RBR.

Technical specifications:

• Profile type: K29 — single-acting rod buffer seal
• Sealing element material: PU (polyurethane, 92 Shore A)
• Back-up ring material: POM (polyoxymethylene)
• Inner diameter d: 90 mm (3.543")
• Outer diameter D: 105.5 mm (4.153")
• Installation width H: 6.3 mm (0.248")
• d × D × H (inches): 3.543" × 4.153" × 0.248"
• Tolerance d: f8
• Tolerance D: H11
• Maximum operating pressure: 400 bar
• Temperature range: –30°C to +100°C (mineral oil)
• Maximum sliding speed: 0.5 m/s
• Working media: mineral oils HFA, HFB, HFC (DIN 51524)
• Sliding surface roughness Ød: Ra ≤ 0.4 μm / Rmax ≤ 3.2 μm

Suitable for hydraulic cylinders used in construction machinery, forklift trucks, injection moulding machines, agricultural machinery, cranes and standard cylinders. Available at lemming.shop.