Allweiler Mechanical Seal 032mm MPN 38543 Lot of 2

This lot contains two (2) genuine OEM spec Allweiler Mechanical Seals (032mm, MPN 38543) for heavy duty marine, offshore and industrial centrifugal and screw pump applications. The shaft sealing system works in tough engine room settings with constant exposure to marine gas oils (MGO), heavy fuel oil (HFO), lubrication oil, fresh water and seawater cooling loops.

MPN 38543 features a single conical spring, unbalanced push-type geometry and precision-lapped seal faces to stop fluid migration on 32 mm drive shafts, while ensuring low friction and minimum thermal build-up under continuous operational loads up to 16 bar and 180°C.

Model Details

• Manufacturer: Allweiler GmbH (CIRCOR Group)
• Manufacturer Part Number (MPN): 38543 / 032 433.01
• Pump Item Position Reference: 433.01 (Standard Allweiler Pump Shaft Seal Assembly)
• Nominal Shaft Diameter: 32 mm (032 Size Code)
• Seal Design Type: Single Conical Spring, Unbalanced Rotary Mechanical Seal
• Quantity Included: 1 Lot of 2 Mechanical Seals

Key Features

1. Precision Lapped Sealing Faces: High-grade Silicon Carbide (SiC) and Carbon/Ceramic face pairing ensures zero-leakage performance under dynamic pressure fluctuations.
2. High Thermal & Chemical Resistance: Outfitted with premium FKM/Viton elastomer bellows and O-rings rated for operation up to 180°C and compatible with aggressive marine fuels and lube oils.
3. Heavy-Duty Conical Spring Drive: Provides uniform axial loading across the sealing faces to prevent vibration-induced shaft wear and premature axial deflection.
4. Corrosion-Resistant Metal Structure: Constructed with high-grade AISI 316 stainless steel retainer components and spring housing for extended durability in marine saltwater environments.
5. OEM Direct-Fit Engineering: Manufactured to exact DIN 24960 / EN 12756 dimensions, eliminating shaft sleeving modifications during engine room pump overhauls.

Compatible Pump Models

• Allweiler Screw Pumps: BAS, SPF, TRILUB, SN Series, NIM Series (150-250, 200-250, 250-250)
• Allweiler Centrifugal Pumps: NT, NB, NI, NAM, NTT High-Temp Thermal Oil Series
• Allweiler Pump Assembly Reference: 0008055515 / Item Code 433.01

Primary Industrial & Marine Applications

• Main Engine Lube Oil Transfer & Booster Pumps
• Heavy Fuel Oil (HFO) & Marine Gas Oil (MGO) Supply Modules
• Boiler Feedwater & High-Temperature Thermal Oil Loops
• Marine Centrifugal Bilge, Ballast, and General Service Pumps
• Industrial Hydraulic Power Unit (HPU) Circulation Systems

Chief Engineer’s Guide

When replacing a 32mm Allweiler mechanical seal in an engine room pump, never compromise on shaft cleanliness or spring direction. Pay close attention to these field-proven installation procedures:

• Verify Shaft Runout and Radial Play: Before installing MPN 38543, ensure shaft radial runout does not exceed 0.05 mm and axial end-play is under 0.1 mm. Excessive vibration will chip the brittle Silicon Carbide faces.
• Conical Spring Rotation Direction: Conical single-spring seals are rotation-dependent. Inspect the coil orientation relative to the shaft rotation when viewed from the drive end to ensure the spring tightens onto the shaft during operation rather than unwinding.
• Elastomer Lubrication: Use a mild soapy water solution or P-80 assembly lubricant when pushing the FKM secondary seal over the shaft step. Never use grease or petroleum jelly, as petroleum-based lubricants attract carbon dust and cause face slip or elastomer swelling.
• Face Cleanliness: Wipe both sealing faces with isopropyl alcohol and an lint-free precision wipe prior to final casing closure. Even a single particle of soot or dirt trapped between the faces will cause immediate micro-fretting and leakage upon startup.
• Pre-Commissioning Priming: Always vent the seal chamber completely and ensure the pump casing is fully primed before starting. Dry running a SiC/Carbon seal for even 5 seconds will thermal-shock the face, leading to immediate fracture and catastrophic failure.

Frequently Asked Questions

What shaft size does the Allweiler 38543 mechanical seal fit?

The Allweiler MPN 38543 mechanical seal is precisely sized for a 32 mm inner diameter (ID) pump drive shaft, with an outer diameter of 47 mm and an operating length of 38 mm.

Can this mechanical seal handle high-temperature fuel oil applications?

Yes, equipped with FKM (Viton) secondary elastomers and high-grade Silicon Carbide/Carbon seal faces, MPN 38543 is rated to withstand continuous operating temperatures up to 180°C (-35°C to +180°C).

How do I know if the conical spring is installed in the correct direction?

Conical spring mechanical seals depend on shaft rotation. When looking at the seal from the stationary seat end, the spring coil must wrap in a direction where shaft rotation causes the coil to grip tighter around the shaft during normal pump operation.

Is this lot compatible with Allweiler screw pumps?

Yes, MPN 38543 is a standard mechanical seal specification across many Allweiler screw pump models (including SPF, BAS, TRILUB, and SN series) as well as select centrifugal marine pumps