ZW Self-priming Non-clogging Sewage Pump

1. Product Definition

The ZW self-priming non-clogging sewage pump is a dedicated self-priming pump for sewage application. Unlike the ZX clean-water self-priming pump, it is designed to pump sewage containing solid particles, fibrous debris, feces and silt. No foot valve is required on the suction pipeline; priming water only needs to be filled for the first startup, and repeated refilling is unnecessary thereafter.

Code meaning: Z = Self-priming type; W = Non-clogging sewage discharge type. It is a national standard horizontal industrial pump, mostly driven by 380V three-phase power supply, available in cast iron and 304 stainless steel constructions.

Model example: 50ZW15-30-3

50: Inlet & outlet nominal diameter: 50 mm

ZW: Self-priming non-clogging sewage pump

15: Rated flow rate: 15 m³/h

30: Rated head: 30 m

3: Matched motor power: 3 kW

2. Working Principle

The pump casing is equipped with a large-capacity priming chamber which shall be fully filled with water for initial commissioning. When the pump starts, the rotating impeller drives the stored water to carry entrapped air from the suction pipe and discharge the air-water mixture upward. Gas-liquid separation takes place inside the separation chamber: air is exhausted through the discharge port while separated liquid flows back into the pump chamber via reflux holes. Negative pressure forms in the suction pipeline, and atmospheric pressure pushes low-level sewage into the pump to realize self-priming operation.

Rated self-priming lift: 4.5～5.5 m; maximum limit ≤6 m.

3. Core Construction

Impeller: Semi-open large-flow-path non-clogging double-vane impeller The ZX pump adopts closed small-flow-path impeller only applicable for clean water. In contrast, the ZW pump features an extra-wide flow passage, permitting passage of solid particles up to 60% of pump nominal diameter and fibrous materials around 5 times the pump diameter, effectively avoiding blockage caused by rags and fecal impurities.

4. Key Technical Parameters

Flow range: 6～300 m³/h

Head range: 8～50 m

Motor power: 0.75 kW～55 kW

Allowable medium temperature: ≤80 ℃

Cast iron version: applicable for pH 6~9 medium;

304 stainless steel version: applicable for pH 2~13 medium including acidic/alkaline wastewater and seawater.

Applicable medium: Domestic sewage, fecal wastewater, mud slurry, papermaking pulp, impurity-laden wastewater and mildly corrosive wastewater.

5. Product Advantages

✅ Excellent non-clog sewage handling capacity: capable of pumping feces, plastic bags, silt and fibrous waste; installed above ground instead of being submerged like submersible sewage pumps. ✅ Inherent self-priming performance: foot valve eliminated from suction piping; the pump can reprime automatically if air intrudes into pipelines. ✅ Surface-mounted layout: easy maintenance, suitable for pump house and open-air outdoor installation. ✅ Dual-purpose design: applicable for both sewage and clean water transportation.

6. Application Scenarios

Municipal & residential communities: Basement sewage lifting, septic tank sludge extraction and residential drainage.

Aquaculture industry: Fish pond drainage, biogas digester manure pumping and livestock farm wastewater treatment.

Light industry & factories: Papermaking pulp transfer, food processing wastewater, printing & dyeing wastewater and construction site muddy water drainage.

Agricultural rural application: Silt-containing river water extraction, farmland flood drainage and raw manure irrigation.