Product Overview
The WQK series cutter-type submersible sewage pump is engineered for demanding wastewater environments where fibrous materials, rags, plastics, and other stringy solids would quickly clog conventional pumps. By combining a dedicated cutting mechanism with a large-passage anti-clogging impeller and a double-row mechanical seal system, the WQK delivers reliable, maintenance-friendly performance in the most challenging sewage applications.
Key Technical Parameters
| Parameter | Range / Specification |
|---|---|
| Media Temperature | ≤ 60°C |
| Media Density | 1.0 – 1.3 kg/dm³ |
| pH Range | 5 – 9 |
| Fiber Passage Capability | Up to 5× pump caliber in length |
| Solid Particle Passage | Up to 50% of pump caliber in diameter |
| Mechanical Seal | Double-row series seal (tungsten carbide) |
| Continuous Operation | 8,000+ hours (seal life) |
| Installation Types | Fixed auto-coupling / Portable free-standing |
Double-Row Series Mechanical Seal System
The WQK employs a double-row series mechanical seal constructed from hard, corrosion-resistant tungsten carbide (SiC). This dual-seal arrangement provides two independent barriers between the pumped media and the motor chamber, dramatically reducing the risk of motor contamination.
Oil-Water Detection Probe
An oil-water probe is installed in the oil chamber between the two mechanical seals. If the lower seal begins to leak, media entering the oil chamber triggers the probe, which sends an alarm signal and initiates pump protection — before the upper seal or motor winding is compromised. This early-warning system prevents costly motor failures and extends overall pump life.
Oil Chamber Maintenance
The oil chamber should be refilled or replaced every 300–500 operating hours (using 10–30 grade machine oil) to maintain proper lubrication of the mechanical seal faces. Regular oil maintenance is the single most effective step in extending seal service life.
Large-Passage Anti-Clogging Impeller
The impeller and volute are designed with oversized flow passages that allow fibrous materials up to five times the pump’s discharge diameter in length, and solid particles up to 50% of the discharge diameter, to pass through without blockage. This design philosophy prioritizes passage capability over maximum hydraulic efficiency — a deliberate trade-off that minimizes clogging incidents in real-world sewage conditions.
Integrated Cutting Mechanism
Upstream of the impeller, a dedicated cutter assembly rotates against a fixed ring to slice through long fibers, rags, plastic strips, and other stringy materials before they reach the impeller. This two-stage approach — cut first, then pass — is what distinguishes the WQK from the standard WQ submersible sewage pump, which relies solely on large passages without cutting action.
Automatic Coupling Installation System
The WQK supports a dual-rail automatic coupling installation system. A special base is fixed to the bottom of the sump, connected to the discharge piping. Guide rails extend to the top of the pit. The pump, mounted on a carrier bracket, slides down the rails and automatically couples to the base with a sealed connection — no bolts, no entry into the sump required for installation or routine removal.
This system offers significant advantages:
- Rapid installation and removal — maintenance personnel do not need to enter the sewage pit
- Accurate re-positioning — the guide rails ensure the pump couples correctly every time
- Reduced downtime — a faulty pump can be lifted out and a replacement lowered in within minutes
Automatic Control & Protection Cabinet
An optional fully automatic control cabinet monitors the pump’s operating condition and provides comprehensive protection:
- Leakage detection — alarms if water enters the motor chamber
- Overload protection — shuts down the pump if current exceeds the rated value
- Over-temperature protection — monitors winding temperature
- Phase-failure protection — prevents single-phase operation that would burn the motor
Float Switch Level Control
A float switch can be configured to automatically start and stop the pump based on sump level, enabling fully unmanned operation. The pump starts when liquid reaches the high-level set point and stops at the low-level set point.
Operating Conditions & Limitations
- Media temperature must not exceed 60°C
- Media density should remain between 1.0 and 1.3 kg/dm³
- pH value must be within the 5–9 range
- Pumps without internal self-circulation cooling must not have the motor section more than half exposed above the liquid surface
- Operating head should remain within the rated range to prevent motor overload — generally not below 60% of rated head
- Motor current must not exceed the nameplate rated current during operation
Model Designation Example
80 WQK 40-15-4
- 80: Nominal discharge diameter (mm)
- WQK: Cutter-type submersible sewage pump
- 40: Rated flow (m³/h)
- 15: Rated head (m)
- 4: Rated motor power (kW)
Optional suffixes: JY (with agitation device), P (stainless steel), B (explosion-proof).
Typical Applications
- Municipal wastewater treatment plant drainage and lift stations
- Residential quarter sewage collection and transfer
- Commercial building basement drainage
- Hospital and hotel sewage discharge
- Factory process wastewater with fibrous contaminants
- Mining and exploration site dewatering
- Rural biogas digester slurry transfer
- Construction site dewatering with debris-laden water
FAQ
Q1: What is the difference between WQK and standard WQ submersible sewage pumps?
The WQ pump relies on a large-passage impeller to pass solids without clogging. The WQK adds an integrated cutting mechanism upstream of the impeller that slices through long fibers, rags, and stringy materials before they reach the impeller. The WQK is the better choice when the media contains significant fibrous or stringy content; the WQ is sufficient for media containing only granular solids.
Q2: How often should the mechanical seal oil be changed?
Under normal operating conditions, the oil chamber should be drained and refilled with fresh 10–30 grade machine oil every 300 to 500 hours. After pumping particularly thick or viscous slurry, rinse the pump in clean water for several minutes before storage to prevent deposit buildup.
Q3: What happens if the mechanical seal fails?
The double-row series seal provides two independent barriers. If the lower seal begins to leak, media enters the oil chamber and triggers the oil-water probe, which sends an alarm and initiates protective shutdown before the upper seal or motor is affected. This early-warning design prevents catastrophic motor failure.
Q4: Can the pump run dry?
Pumps without an external water-jacket cooling system must not run with the motor section exposed above the liquid surface for extended periods — the motor relies on surrounding liquid for cooling. Pumps equipped with an optional water-jacket external circulation cooling system can operate safely in dry conditions.
Q5: What is the advantage of the automatic coupling system?
The auto-coupling system allows the pump to be installed and removed by sliding it along guide rails, without entering the sump or disconnecting piping. This dramatically reduces maintenance time and eliminates confined-space entry hazards associated with traditional bolted installations.