A submersible WQ sewage pump in the 50 m³/hr, 30 m head, 5 kW class — the SKU code "Q 50-30-5" decoded as Q=50 mm drain, 50 m³/hr, 30 m, 5 kW — is quoted with a 60 °C liquid ceiling, 1200 kg/m³ density limit, and 380 V / 50 Hz rating, and is the default workhorse Chinese OEMs ship into light-commercial and municipal lift-station duty [S5].
Across Made-in-China.com, the high-pressure submersible sewage category lists 580 - 28,000 USD per piece (1-Piece MOQ) from Diamond-Member audited suppliers in Shandong, giving buyers a concrete FOB band for OEM RFQs as of 30 April 2026 [S7]. For broader definition of a sewage pump and the cast-iron / ductile-iron volute architecture typical of WQ designs, the cross-vendor build pattern is essentially identical between Okorder listings and Sino-foreign JV catalogues [S2][S4][S6].
Price Decoding: FOB Bands by Pump Class
The Made-in-China high-pressure submersible sewage index shows a 580 - 28,000 USD FOB spread per piece, MOQ 1, sourced from Diamond-Member audited manufacturers — that 48× range is not noise, it tracks flow / head / cast-iron mass / impeller pass diameter [S7].
Small vertical centrifugal sewage pumps on Okorder's WQ blockage-free line are typically priced in the low-hundreds-USD range, reflecting the 1-7.5 kW envelope and the integrated-motor submersible architecture (motor and pump as one unit) [S2]. Gasoline-engine-driven WQ-series slurry units carry a price premium for the petrol engine and trailer chassis but stay in the sub-3,000 USD band on most listings [S4]. The WQ 50-30-5 datasheet baseline — 50 m³/hr, 30 m, 5 kW, 380 V / 50 Hz, pH 5-9 — is the reference SKU buyers should pin their RFQ to before negotiating deviations [S5].
Operating Envelope That Drives the Quote
WQ submersibles are rated for medium temperatures up to 60 °C, densities up to 1200 kg/m³, and a pH window of 5 - 9, with the running level never allowed to drop below the manufacturer's permitted minimum liquid level [S5].
Voltage and frequency are 380 V / 50 Hz on the standard 3-phase SKU; deviations to 220 V / 60 Hz, single phase, or 525 V / 60 Hz all move the price and the lead time because the stator lamination and terminal box change [S5]. The gasoline-engine WQ variant replaces the electric motor with an air-cooled petrol engine, allowing pit-side deployment where 380 V three-phase is not available, but trades off continuous-duty thermal headroom and emissions compliance [S4]. Zhejiang Better Pump's product line — sewage, fire, centrifugal, self-priming, multistage, submersible mixer, submersible aerator, low-speed flow — shows how the same impeller-casting line is amortised across adjacent SKUs, which is why sewage-pump price quotes are sensitive to whether a unit is built on a dedicated line or shared tooling [S3].
Sourcing Map: Who Builds What in China
Shandong Blossom Pump is one of the audited Diamond-Member suppliers inside the 580 - 28,000 USD price corridor on Made-in-China, which is the cluster most EU and Middle East buyers RFQ first [S7].
Zhejiang Better Pump runs an integrated product line covering sewage, fire, centrifugal, self-priming and multistage pumps plus submersible mixers and aerators, positioning it as a single-vendor option for WWTP packages that need matched hydraulics [S3]. Jiangsu Burks markets a Sino-foreign joint-venture BKL sewage-pump range alongside its imported-pump selection service, an option worth quoting when the spec demands ISO 5199 or closer impeller-balance grades than a domestic OEM will accept on a tight budget [S6]. SONHO Pump Mfg, the CENS-listed Taiwanese-rooted supplier, sits in the same product family and is the route for buyers who need English-language datasheets and TUV-grade documentation out of the box [S1]. The centrifugal pump architecture is the mechanical baseline almost all of these WQ units share, so hydraulic-curves cross-checking is the same exercise regardless of vendor label.
Spec Comparison Across Pump Types
Three decision criteria separate the buyable SKUs: drive type, solids pass diameter, and lift envelope — and they line up as follows on the current 2026 China OEM index [S2][S4][S5][S7].
Electric submersible WQ (Q 50-30-5 reference): 50 m³/hr / 30 m / 5 kW, 50 mm drain aperture, 380 V / 50 Hz, 60 °C cap, 1200 kg/m³ density cap, pH 5-9 — lowest price band, suited to permanent lift-station installation [S5]. Gasoline-engine WQ slurry: same 50 mm drain and WQ hydraulic, but petrol drive, mobile deployment, higher unit cost because of the engine and skid — suited to construction-site dewatering and emergency bypass [S4]. High-pressure submersible sewage: extends the same WQ architecture into the multi-stage / higher-head envelope, lifting FOB into the 580 - 28,000 USD corridor, suited to long-distance forcemain duty [S7]. Small vertical centrifugal sewage (non-submersible, dry-pit): 1-7.5 kW envelope, dry-pit installation, lower solids-handling margin — suited to indoor plant rooms where a flooded sump is not acceptable [S2]. A diaphragm pump is the comparator for chemical-sludge or shear-sensitive duty; it is a different mechanism (positive-displacement) and should not be confused with a WQ centrifugal on the same RFQ.
Failure Modes and Spec Traps to Watch in the RFQ
Continuous dry-run is the first warranty-void trap on a WQ submersible — the mechanical seal depends on the pump running immersed, and the manufacturer's "permitted lowest liquid level" is a hard line, not a guideline [S5].
A second trap is using a WQ slurry pump on a duty that is actually a gear pump or diaphragm pump job — high-viscosity sludge, shear-sensitive floc, or metered chemical dosing will chew up a WQ impeller and will not deliver stable flow. A third is accepting 220 V / 60 Hz or 110 V single-phase on a 5 kW WQ without confirming the supplier has a stocked stator and a matching cable gland — otherwise the order slips 30-60 days on a stator rewind. The WQ 50-30-5 datasheet also flags the pH 5-9 window: outside that band the mechanical seal and elastomers degrade, and the 1200 kg/m³ density cap is a solids-loading limit, not a viscosity limit [S5].
Related Sourcing Context for a WWTP Package
For a buyer building a 2026 WWTP or lift-station package, the Sewage Pump vs Metering Pump: Spec-Driven Selection for 2026 Pumping Duties comparison covers the boundary between WQ centrifugal duty and PD metering duty, and is the natural next read after pinning the WQ 50-30-5 reference SKU. The Desalination Supply Chain 2026: RO Membrane, ERD and HP Pump Sourcing Map piece covers the high-pressure pump envelope that overlaps with the 580 - 28,000 USD FOB band on the high-pressure submersible sewage index [S7]. For buyers cross-quoting WWTP auxiliaries, the Tank Cleaning Machine Calibration and Maintenance: Spec Bands, Service Intervals article covers the rotating-jet spray ball class that typically rides alongside a WQ lift station.
Trackable signals to watch: (1) MOQ drift on the Made-in-China high-pressure submersible index — a move from 1-Piece MOQ to higher tier typically precedes a 4-8 % price step in the same week; (2) any 380 V / 50 Hz to 380 V / 60 Hz variant added by Shandong Blossom or a comparable Diamond-Member audited supplier, which would unlock Middle East and North Africa tenders without a rewind [S7].