Iwaki EWN-B-21-VH Dosing Pump
Spare Parts for EWN-B-21-VH Dosing Pump
Product Summary
The Iwaki EWN-B21-VH is a high-performance electromagnetic metering pump featuring a PVC pump head with EPDM seals and Hastelloy C276 valve balls. Designed for the precise injection of alkaline chemicals, coagulants, and other fluids compatible with EPDM, it offers a stroke rate of up to 360 spm and digital 1:1 control logic.
- High-Speed Dosing: 360 strokes per minute capability ensures high turndown ratios and smooth chemical flow.
- Wet End Materials (VH): PVC Head, EPDM Seals, and Hastelloy C276 Valve Balls suitable for caustics and specific water treatment chemicals.
- Multi-Voltage Power: Universal 100-240 VAC power supply adapts to any global site requirement.
- Digital Controller: The B-Series controller features a clear LCD display with adjustable stroke rate (0-100%) and stroke length.
- Waterproof Design: Robust IP65 equivalent construction protects the drive unit from splashing and corrosive environments.
Spare Parts List
| Select | Qty | Part Number | Description | Material / Spec |
|---|---|---|---|---|
| 1 | EH1971 | Diaphragm | PTFE / EPDM | |
| 1 | EWN0143 | Connector Set (Check Valves) | VH (PVC/EPDM/Hastelloy) | |
| 1 | EW0402 | Pump Head Unit | PVC | |
| 2 | EWN0005 | Fitting (4x6mm) | PVC | |
| 2 | EWN0010 | Fitting Nut | PVC | |
| 1 | EWN0003 | Air Vent Body B | PVC | |
| 1 | EWN0070 | Air Vent Body A | PVC | |
| 1 | EWN0009 | Lock Nut | PVC | |
| 1 | EH0059 | Retainer | PPS | |
| 2 | EH0060 | Valve Ball | Hastelloy C276 | |
| 2 | EH0062 | Valve Seat | EPDM | |
| 4 | EH0029 | O-Ring (Valve) | EPDM | |
| 4 | EH0270 | Hex Socket Head Bolt | Stainless Steel |
Exploded Parts Views
Key Technical Specifications
| Parameter | Value |
|---|---|
| Model / Curve | EWN-B21-VH |
| Rated Power | 20 W |
| Voltage / Frequency | 100-240V / 50-60Hz |
| Rated Current | 0.8 A |
| Discharge Connection | 4mm x 6mm Tubing |
| Impeller Type | Diaphragm (PTFE+EPDM) |
| Installation Type | Surface Mount / Solenoid Dosing |
Troubleshooting, Common Faults & Solutions
Pump does not start
Likely Cause: Disconnected power or fuse blown.
Action / Part: Check 100-240V supply and cable integrity.
Pump stroke sound is audible but no liquid
Likely Cause: Gas Lock (Air binding) in the pump head.
Action / Part: Open Air Vent Valve (EWN0003/70) to bleed trapped air.
Liquid leakage from head
Likely Cause: Diaphragm damaged or bolts loose.
Action / Part: Inspect Diaphragm (EH1971) and tighten Head Bolts (M4).
Flow rate fluctuates
Likely Cause: Debris in check valves or voltage instability.
Action / Part: Clean/Replace Valve Balls (EH0060) and Seats (EH0062).
Over-feeding (Siphoning)
Likely Cause: Discharge point is lower than the tank level.
Action / Part: Install a Back Pressure Valve or Anti-Siphon Valve.
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