Aftermarket replacements for EagleBurgmann M7N / H7N | AESSEAL W07DMU / W07DMBU | Vulcan 1677 / 1678
Luwint M7N and M7B are O-ring mounted, wave spring mechanical seals for pump maintenance and replacement applications. Both use a compact rotary assembly, with face and elastomer options to suit different liquids and operating conditions.
M7N is an unbalanced design for plain shafts. M7B is a balanced design for stepped shafts or sleeves, with a higher catalogue pressure limit. Selecting between them requires a check of the shaft arrangement, working length and stationary seat, as well as the operating duty.
Why Choose the M7N / M7B Range
-
Two shaft configurations: M7N suits plain-shaft installations, while M7B accommodates the stepped-shaft arrangement required by its balanced design.
-
Wave spring loading: provides axial force to maintain contact between the sealing faces within a compact assembly.
-
Set-screw drive: secures the rotary assembly to the shaft or sleeve.
-
O-ring secondary sealing: offers elastomer choices for different liquids and temperatures.
-
Material options: allows the sealing faces and stationary seat to be selected for the application.
Choosing the Correct Model
| Feature | M7N | M7B |
|---|---|---|
| Seal design | Unbalanced | Balanced |
| Shaft arrangement | Plain shaft or sleeve | Stepped shaft or sleeve |
| Corresponding EagleBurgmann family | M7N | H7N |
| Luwint catalogue pressure limit | Up to 17 bar | Up to 40 bar |
| Shaft dimensions to check | Diameter D | Both diameters d and D, plus step position |
The M7B catalogue uses paired dimensions such as 25/30 mm. These identify two diameters in the stepped-shaft arrangement; they are not alternative nominal sizes.
For either model, confirm the rotary outside diameter, rotary working length L1, stationary-seat diameter and seat length L2. L1 excludes the stationary seat. The installed assembly must match the pump’s available axial and radial space.
M7B should not be selected as a pressure upgrade to M7N without checking the shaft or sleeve geometry and complete installation.
Typical Operating Conditions
| Parameter | Luwint catalogue range or limit |
|---|---|
| M7N shaft sizes listed | D = 22–100 mm, in selected metric sizes |
| M7B stepped-shaft sizes listed | Selected d/D pairs from 18/22 to 95/100 mm |
| M7N pressure | Up to 17 bar |
| M7B pressure | Up to 40 bar |
| Sliding speed, both models | Up to 20 m/s |
| Temperature, both models | −30°C to +200°C |
Actual limits depend on seal size, face materials, elastomer, liquid and operating conditions. Maximum pressure, speed and temperature should not be assumed to apply simultaneously.
Common Cross-References
| Luwint | EagleBurgmann / Burgmann | AESSEAL | Vulcan |
|---|---|---|---|
| M7N | M7N | W07DMU; earlier W07DM | 1677 |
| M7B | H7N | W07DMBU; earlier W07DMB | 1678 |
These references identify corresponding seal families. Confirm the working length, shaft geometry, stationary-seat configuration and materials before ordering. Suffixes and alternative seat arrangements can change the required dimensions.
Where It Is Used in Australia
With suitable materials and a verified dimensional match, the M7N / M7B range can be selected for:
-
Industrial water transfer and circulation
-
Cooling-water and plant utility pumps
-
Chemical transfer involving compatible liquids
-
Lubricating-oil and general process pumping
-
Wastewater duties following assessment of solids and abrasion
Selection should account for fluid chemistry, viscosity, solids content and seal-chamber conditions.
Materials Available
The Luwint catalogue lists:
-
Seal faces and stationary seats: Carbon, Ceramic, Silicon Carbide (SiC), Sintered Silicon Carbide (SSiC) and Tungsten Carbide (TC).
-
Elastomers: Nitrile (NBR), EPDM and Viton (FKM).
Contact Luwint to confirm the appropriate face pairing and elastomer for your liquid and duty, together with availability for the required model and size.
Sydney Supply. Help with Selection.
Contact Luwint for current stock availability, pricing and dispatch timing.
For help identifying a replacement, send the pump make and model, clear photos of the old seal, shaft or sleeve dimensions, rotary working length and stationary-seat dimensions. For M7B, include both shaft diameters and the step position.
Please also provide the liquid, operating temperature, pressure and shaft speed.
Ask us for the full PDF catalogue and the M7N / M7B dimensional drawing.
Contact: Wayne Liao
Email: wayne@luwintonline.com
Mobile: 0433 986 633
LUWINT supplies aftermarket replacement products for original equipment applications. We are an independent supplier and are not affiliated with or endorsed by EagleBurgmann, AESSEAL or Vulcan. Brand names and model references are used solely for identification and cross-reference.