502 Cartridge Mechanical Seal

The 502 series has a broad size range and several installation dimensions that change across the range. That makes it a product where "502 + shaft diameter" is a good starting point, but not always enough for a confident replacement order. The technical drawing separates shaft sizes 14-68 mm and 70-100 mm in the installation area, so matching the existing seal envelope matters.

For Qixing, this creates a practical purchasing workflow: first identify the 502 size, then check the stationary seat, shaft and housing dimensions, and finally confirm the fluid, pressure, temperature and speed before production.

What Makes the 502 Series Distinctive

• Wide shaft coverage from 14 mm to 100 mm.
• Operating range: -20°C to +120°C, pressure up to 2.5 MPa and sliding speed up to 15 m/s.
• Standard stationary seat listed as BO; BP is listed as an alternative.
• The technical drawing identifies the BO seat with DIN24960 notation.
• The drawing includes a flushing/cooling port in the housing area.
• The 502 is presented by Qixing as a 502 Cartridge Mechanical Seal and uses an elastomer-bellow sealing structure.
• Material-code options are provided for stationary ring, rotary ring, secondary seal, spring and metal parts.

502 at a Glance

BO Seat or BP Seat?

The technical specifications lists BO as the standard seat and BP as the alternative. It also marks the BO seat with a DIN24960 reference in the drawing. However, the product specifications does not explain a performance difference between BO and BP. For a replacement order, the safest approach is to identify the seat used in the existing installation and confirm the relevant dimensions instead of treating the two codes as automatically interchangeable.

A Better Way to Match a 502 Replacement

Fluid Selection: Read the Application Line Carefully

The product specifications list clean water, sewage water, oil and other moderately corrosive fluids. That is useful for initial filtering, but it is not a universal chemical-compatibility statement. Sewage can contain suspended solids, oils can contain additives, and corrosive liquids vary greatly in concentration and temperature.

For this reason, Qixing should confirm the actual medium before selecting the face and secondary-seal material codes. This is especially important when the application is more aggressive than the product specifications's wording "moderately corrosive."

Material Code Options

The technical specifications gives material options as codes only. This product page keeps those codes without inventing unsupported material names:

• Stationary ring: V1 / Q1 / Q2 / U2 / U1
• Rotary ring: B / A / Q1 / Q2 / U1 / U2
• Secondary seal: P / E / V
• Spring and metal parts: F / G

What to Measure Before Removing the Old Seal

If the 502 is being sourced as a replacement, maintenance teams can save time by recording a few dimensions before the old assembly is discarded. Measure the shaft diameter first, then record the seat outside diameter and axial installation length. If possible, also note the flushing/cooling port arrangement shown in the technical drawing.

• Shaft diameter d
• Seat and housing diameters D3 / D4 / D6 / D7
• Overall and working lengths L / L3 / L4
• Secondary axial dimensions L5 / L6 / L2 / L38
• Existing seat style and visible model marking
• Clear photos of the complete assembly and stationary seat

Why Choose Qixing for the 502

Qixing, the mechanical seal brand of Ningbo Yade Fluid Connector Co.,Ltd, manufactures and supplies mechanical seals for industrial buyers. For the 502 series, we can review model, shaft size, dimensions, seat requirement and duty conditions together before quotation, which is more useful than quoting from the model number alone.

For OEM and replacement projects, customized selection can be based on drawings, existing samples, dimensional measurements or operating data. Specific production capacity, certification or delivery requirements can be confirmed separately for the project rather than assumed on the product page.

FAQ

What shaft sizes are available for the 502 series?

The product specifications list 502 sizes from 14 mm to 100 mm shaft diameter.

What operating limits are shown for the 502?

The operating range is -20°C to +120°C, pressure up to 2.5 MPa and sliding speed up to 15 m/s.

Which stationary seat is standard?

BO is listed as the standard seat, while BP is listed as an alternative.

Does the product specifications reference DIN24960?

Yes. The technical drawing labels the BO seat with a DIN24960 reference.

What fluids are listed for the 502?

Clean water, sewage water, oil and other moderately corrosive fluids are listed.

Is the 502 a cartridge seal or an elastomer bellow seal?

Qixing presents this product as the 502 Cartridge Mechanical Seal. Its elastomer-bellow sealing structure should be matched by dimensions and operating conditions before ordering.

Can I order by shaft diameter only?

Shaft diameter is the first selection point, but seat style and installation dimensions should also be checked for replacement work.

What should I send for a replacement quote?

Send the existing model, shaft size, seat style, installation dimensions, medium, pressure, temperature, speed and clear photos if available.

Can Qixing customize the 502 seal?

Qixing can support customized matching based on dimensions, samples and operating data. Any non-standard configuration should be confirmed case by case.

Are BO and BP automatically interchangeable?

BO is the standard seat and BP is an alternative. Confirm dimensions and installation requirements before treating the seat options as interchangeable.

502 Dimension Table

Dimensions are shown in millimeters. Model names below use the Qixing-facing 502 designation.