CAT 391-9818 BEARING-SLV-GD

CAT 391-9818 YM is a Caterpillar genuine gasket assembly, commonly used in static sealing joints of engine or hydraulic systems to prevent oil and gas leaks and contaminant ingress. The following are core original factory specifications and application information; replacement parts are not included.

Core Technical Parameters

Item Details
Part Model: CAT 391-9818 YM (GASKET ASSEMBLY – YM)

Product Type: Modular gasket assembly, including metal skeleton + elastic sealing layer, suitable for high-pressure static sealing conditions, used for sealing flange and shell mating surfaces.

Material: Metal skeleton: Cold-rolled steel plate (SPCC); Sealing layer: Nitrile rubber (NBR), excellent oil resistance and aging resistance.

Surface Treatment: The metal skeleton is galvanized and passivated for corrosion protection; the rubber layer is molded and vulcanized, ensuring high fitting accuracy and eliminating air bubbles and missing adhesive.

Key Dimensions: Applicable flange diameter approximately 120 mm, total thickness 3.2 mm (metal skeleton 2.0 mm + rubber layer 1.2 mm), bolt hole distribution circle diameter 100 mm, suitable for M10 bolts.

Single Weight: Approximately 0.28 kg (0.62 lbs)

Sealing Performance: Working pressure ≤2.5 MPa, working temperature -30℃ ~ +100℃, suitable for mineral oil, hydraulic oil, and other media.

Matching Requirements: Surface flatness ≤ 0.05 mm, surface roughness Ra ≤ 1.6 μm, bolt preload torque 25–30 N・m.

Structure and Core Characteristics:

Metal-Rubber Composite Structure: The metal skeleton provides rigid support to prevent deformation during installation; the nitrile rubber sealing layer has excellent elasticity, compensating for minor deformations and gaps at the mating surfaces, ensuring reliable sealing.

Corrosion-Resistant Design: The galvanized and passivated metal skeleton is suitable for humid and dusty conditions, extending the service life of the gasket assembly.

Precise Fit: The molding process ensures precise bolt hole position and dimensional tolerances, perfectly matching original flanges and housings, avoiding leaks due to installation deviations.

Multi-functional Sealing: Can simultaneously seal oil and gas, suitable for static mating surfaces such as engine cylinder head covers, hydraulic pump housings, and valve group flanges, offering strong versatility.

Compatible Machines and Application Scenarios

Excavators: 336D2, 349D2, etc., used for sealing hydraulic pump housing flanges and valve assembly mating surfaces to prevent hydraulic oil leakage and ensure stable hydraulic system pressure.

Loaders: 966K, 972K, etc., compatible with engine cylinder head covers and oil pan flanges to seal engine oil and prevent oil contamination and loss.

Core Applications: Used for sealing static flanges or housing mating surfaces in engines and hydraulic systems, suitable for high-pressure and medium-temperature operating conditions, solving leakage problems caused by gasket aging and deformation, and improving equipment operational reliability.