Name: ZW Self-priming Sewage Pumps
Brand: Shijiazhuang First Pump Factory Co., Ltd.

ZW Self-priming Sewage Pumps

The ZW Self-Priming Sewage Pump is an innovative pump series that integrates self-priming capability and non-clogging solids handling. Developed by refining the structures of ZX self-priming centrifugal pumps and QW submersible sewage pumps, and incorporating advanced international technology, this pump is engineered for efficient transport of wastewater containing large solid particles and long fibrous materials.

Key Features & Advantages of ZW Self-priming Sewage Pumps

Exceptional Non-Clogging Performance: Features a specially designed impeller dual-vane structure that allows the passage of large solid particles up to 60% of the pump's discharge port diameter and fibrous materials with lengths up to 1.5 times the impeller diameter / 5 times the pump port diameter. This ensures reliable, clog-free operation.
High Self-Priming Efficiency: The axial return external mixing system enables superior self-priming. It achieves a self-priming height up to 5m, approximately 1 meter higher than standard self-priming pumps, with a shorter priming time. No bottom valve or initial water filling is required for subsequent operations, though the pump chamber must be filled before the initial start.
Energy Efficient: Utilizing an optimized hydraulic model, these pumps operate 3-5% more efficiently than conventional self-priming pumps.
Robust Construction & Easy Maintenance: Equipped with a new mechanical seal friction pair operating within an oil chamber for enhanced durability. The design is compact, structurally simple, and facilitates easy inspection and maintenance. A direct-coupled version is available for improved concentricity and stability, offering cost benefits albeit with slightly more complex maintenance.
Versatile & User-Friendly: Can be equipped with automatic control panels for unmanned operation. Outdoor-type motors allow installation without a pump house. The flexible installation options enhance convenience and reduce costs.

Structure & Working Principle of ZW Self-priming Sewage Pumps

Structure

Structure & Working Principle of ZW Self-priming Sewage Pumps

No.	Part Name	No.	Part Name
1	Inlet Nipple	9	Impeller
2	Inlet Flange	10	Mechanical Seal
3	Inlet Valve Seat	11	Water Deflector
4	Priming Plugt	12	Bearing Seat
5	Outlet Nipple	13	Pump Shaft
6	Volute Casing	14	Bearing Cover
7	Air-liquit Separating Pipeline	15	Bottom Cover
8	Rear Cover	16	Seal Ring

Working Principle

The pump body is equipped with a liquid storage chamber, which is connected to the pump's working chamber through an upper return hole and a lower circulation hole, forming an axial flow external mixing system of the pump. After the pump stops working, a certain volume of liquid is stored in the pump cavity. When the pump starts, the stored liquid in the pump cavity, under the action of the impeller, carries air and is thrown upwards. The liquid flows back to the working chamber through the mesh of the gas-liquid separation pipe, and the gas is discharged out of the pump, creating a certain vacuum in the pump, thus achieving the self-priming effect.

Technical Specifications & Operating Conditions of ZW Self-priming Sewage Pumps

Flow rate	8-800 m³/h
Head	12-60 m
Efficiency	45%-65%
Pump Weight	100-1400 kg
Motor Power	2.2-55 kW
Net Positive Suction Head (NPSH)	2.0-6.0 m
Medium Temperature	≤ 80°C (standard), up to 200°C available upon request.
Ambient Temperature	≤ 50°C.
pH Range	Cast iron Wetted Parts: 6-9; Stainless Steel wetted Parts: 2-13.
Liquid Specific Gravity	≤ 1240 kg/m³.
Max. Suction Lift	4.5 - 5.5 meters.
Max. Suction Pipe Length	≤ 10 meters.

Applications:

Ideal for handling heavily polluted wastewater and various liquids with solids across numerous sectors, including:

Municipal sewage engineering, urban wastewater treatment plants
Industrial wastewater discharge (paper, food, chemical, pharmaceutical, power plants)
Construction sites, mining operations
Residential sewage stations, hospital and hotel wastewater
Human defense drainage systems, water plant intake
Rural biogas digesters, farmland irrigation

Operation & Maintenance Guidelines:

Pre-Startup: Check rotation direction and ensure smooth rotation. For the first use, fill the pump chamber completely with liquid. Ensure adequate stored liquid in the pump for all startups.
Startup: Open the outlet control valve before starting to vent air during the priming process. After starting, adjust the valve to maintain operating pressure within the specified range to prevent motor overload or cavitation.
Monitoring: Regularly check pump and motor temperature during operation. Stop immediately to investigate any unusual noise or vibration.
Shutdown: Close the outlet control valve before stopping the pump to prevent siphoning and loss of prime.
Maintenance: Clean the pump chamber after handling viscous or thick slurries to prevent sediment buildup. Perform routine lubrication and inspection. After 3000 hours of operation, conduct a disassembly inspection and replace worn parts as necessary. For long-term storage, disassemble, clean, lubricate, and store properly.

The ZW Self-Priming Sewage Pump represents a pioneering solution in China's self-priming pump market, effectively replacing WQ/QW submersible sewage pumps in many applications. It combines robust non-clogging performance, high self-priming ability, energy efficiency, and maintenance-friendly design, making it a reliable and versatile choice for demanding wastewater handling tasks.