Tender for Mechanical Seals for Mixers and Grinders by Polish MPWIK

Tender Name: Supply of mechanical seals for pumps, mixers, and grinders produced by Grundfos, Flygt, and KSB

Buyer Background: MPWIK is a municipal enterprise owned by the City of Warsaw, responsible for public services including drinking water production and supply, wastewater treatment, and network maintenance in the Warsaw area.

Tender Description: Supply of mechanical seals for pumps, mixers, and grinders produced by the brands Grundfos, Flygt, and KSB

Procurement Purpose: To ensure the continuous and stable operation of Warsaw's water supply and wastewater treatment facilities by procuring spare parts (mechanical seals) for critical equipment, used for routine maintenance, preventive repairs, and emergency breakdown repairs of existing equipment.

Types of Mechanical Seals:

Mechanical Seals for Pumps: Classified by structure (single, double), by balance type (balanced, unbalanced), by spring type (multiple spring, single spring).

Mechanical Seals for Mixers: Typically shaft seals for submersible mixers, requiring resistance to wastewater environments.

Mechanical Seals for Grinders: Used for blade shaft sealing of submersible grinders, requiring resistance to impact from solid debris.

Key Material Requirements:

Seal Face Materials: Silicon Carbide (SiC) vs. Tungsten Carbide (WC) or Graphite. For handling sandy wastewater, hard-on-hard materials (e.g., SiC/SiC) are typically required.

Elastomer Materials: Fluorocarbon Rubber (FKM) or Ethylene Propylene Diene Monomer (EPDM), requiring resistance to chemical components and temperature fluctuations in wastewater.

Metal Components: Stainless steel (AISI 316) for corrosion prevention.

Quantity: 1 set

Project Content:

Framework Agreement Duration: Expected to be 12-24 months, with orders placed as needed during this period.

Supply Scope: Provide mechanical seals that are fully compatible with the equipment of the aforementioned brands, ensuring original equipment manufacturer (OEM) quality or certified equivalent substitutes.

Quality Assurance: Provide a minimum warranty period of 12 months, ensuring the seals are free from leakage and material defects under conditions of correct installation and use.

Technical Compatibility Confirmation: Suppliers must have the capability to confirm and provide the correct seal models based on the equipment models provided by the buyer.

Emergency Supply Capability: May require supply within 24-48 hours for urgent repair needs.

Warehousing Requirements: Suppliers may need to maintain a certain inventory of commonly used seals.

Applicable Scenarios (within MPWIK's business scope):

Water Treatment Plants: For sealing pump sets used in raw water lifting, chemical dosing, backwashing, etc.

Wastewater Treatment Plants: For sealing key equipment such as inlet pumps, return sludge pumps, submersible mixers, and submersible grinders. This is where the demand for mechanical seals is most concentrated and the operating conditions are most demanding.

Water Supply Networks: For sealing at intermediate booster pumping stations.

Drainage Pumping Stations: For sealing submersible sewage pumps at stormwater and wastewater lifting stations.