Precision Dosing. Reliable Performance. Flexible Control.
Walchem and Iwaki leverage over a century of combined application and engineering expertise to deliver the EWP Series Metering Pumps – an advanced product line optimized for precision chemical dosing across a broad range of industrial applications.
The EWP Series pumps offer flow rates up to 6.7 GPH (25 l/h) and pressure capabilities reaching 300 PSI (20 bar), all within a compact, rugged housing rated to IP66 and a footprint designed for easy installation or ideal for OEM integration.
One Pump, Two Control Options Always Precise.
EWP-L Series
The EWP-L Series pumps combine 360 strokes per minute proven performance into a powerful, compact chassis with manual or external control options to create a robust and easy to operate pump. Two control knobs enable simple and fast output adjustment and selection of proportional analog or pulse input control. With speeds up to 360 strokes per minute and an adjustable stroke length, the EWP-L achieves an exceptional 1800:1 turndown ratio, delivering unmatched versatility and performance among budget-friendly metering pumps.
Built to prime and hold prime, the EWP-L Series pumps are constructed for accuracy, longevity and control, creating a precise chemical injection solution at an economical cost.
EWP-R Series
The EWP-R Series utilize the same compact and powerful pump drive while increasing pump functionality and control. The pumps feature a high-contrast, digital backlit display, a clear visual status indicator, comprehensive alarm features and simple key operation. The large LED status indicator illuminates in multiple colors, presenting real-time visual cues of current operating conditions.
The EWP-R expands proportional control with programmable analog, pulse with Multiply or Divide, Batch, or Interval Batch. Additional control features include external AUX, PRIME, Pre-STOP and Interlock, plus an alarm output relay with pump status.
These features are complemented by a keypad lockout for safety and an integrated 12VDC power supply, making the pump as
sophisticated as it is functional.
Features
EWP Series Metering Pump Features
- High Speed Performance
Operating at 360 strokes-per-minute, EWP Series pumps provide high resolution chemical feed. Most competitive products operate at slower speeds, resulting in slug feeding, accelerated diaphragm wear and poor feed control. - Engineered Longevity
All E-Series pumps feature dual bearing support. The armature and shaft are supported with a bearing on each end, which ensures proper axial movement, enabling the E-Series to operate at 360 SPM while extending the life of the diaphragm and mechanics. - High Compression Ratio
The compression ratio of a metering pump is important because it affects the pump’s ability to prime and vent. The compression ratio is raised when you reduce the dead volume of the pump head during operation. All E-Series pumps feature a very high compression ratio that ensures proper feed especially with off-gassing products (i.e. Sodium Hypochlorite). - Superior Check Valve Performance
Dual Check Valve Assemblies in both suction and discharge fittings feature precision ball guides and tapered seats. Precise machining and molding of parts limit valve ball travel, ensuring that balls fully seat and seal with every stroke. The superior check valve design guarantees fast priming and reliable performance. - Rugged Enclosure
The E-Series pump is the first in its class to deliver a full 2-year warranty — on the entire pump.- Redefining Industrial Performance.
The EWP-Series is built to outperform, with enhanced sealing and superior water resistance. Its rugged IP66 rating holds strong—even without the standard clear splash guard of the EWP-R model.
- Redefining Industrial Performance.
- Flexible Installation
The EWP series feature a removeable secondary base that can be used to mount the pump either on a flat surface, or on a wall, enabling quick removal of the pump without tools and saving valuable space in cabinets and on top of tanks. The base is supplied with EWP-R pumps (optional for EWP-L).
Specifications
EWP Series Metering Pump Specifications
| EWP-L Series Specifications | |
|---|---|
| Manual (MAN) | 0–100% stroke rate control (max. 360 spm) |
| External Control (EXT) | 4–20 mA input proportional to 0–360 spm |
| Operating Frequency | 0–6 Hz, synchronous with 0–360 spm |
| Status LED – EXT Mode | Red LED flashes when operating in EXT mode |
| Status LED – Pump Running | Green LED blinks synchronously with pump strokes |
| Status LED – STOP | Red LED lights when STOP signal is active |
| Dial Function | Simple function dial (Stroke rate adjustment, PLS/ANA mode selector) |
| STOP Control Function | Pump stops when STOP signal is input |
| Pulse Input | Dry contact or open collector |
| Analog Input | 4–20 mA DC (input resistance: 220 Ω) |
| STOP Input | Dry contact or open collector |
| Power Supply Voltage | 100–240 VAC, 50/60 Hz |
| EWL-R Series Specifications | |
|---|---|
| Operation Mode – MAN | 0.1–100% stroke rate (1–360 spm) |
| Operation Mode – EXT (ANA.P) | Analogue preset: 4–20 mA, 0–20 mA, 0–4 mA, 20–0 mA (proportional to stroke rate) |
| Operation Mode – ANA.V | Analogue variable control |
| Operation Mode – PLS.V | Pulse variable control |
| Operation Mode – DIV | Dividing function: ÷1–9999 |
| Operation Mode – MULTI | Multiply function: ×1–9999 |
| Operation Mode – BATCH | Batch operation: 0.1 mL–99.9999 L (0.0001–26.4199 gal) |
| Operation Mode – INT.B | Interval batch operation: 0–9 days, 0–23 hours, 0–59 minutes |
| Flow Rate (INT.B) | 0.1 mL–99.9999 L (0.0001–26.4199 gal) |
| Operational Panel | LCD display: 14-segment (5 digits), 7-segment (4 digits), backlit |
| Status LED – White | Lights when pump is in wait state or menu mode |
| Status LED – Green | Blinks synchronously with stroke during pump operation |
| Status LED – Orange | Blinks synchronously with stroke when Pre-STOP signal is input |
| Status LED – Purple | Lights when STOP signal is input |
| Status LED – Red | Lights when Interlock signal is input |
| STOP / Pre-STOP | Pump continues running during Pre-STOP; stops when STOP signal is input |
| PRIME Function | Maximum spm operation while START/STOP key is held |
| Keypad Lock | PIN number disables keypad operation |
| Interlock Control | Pump stops when interlock contact input is detected |
| AUX Operation | Pump runs at preset AUX speed |
| Buffer Memory – MULTI/DIV | Stores excess pulses up to 65,535 shots (ON/OFF selectable) |
| Buffer Memory – BATCH | Accumulates flow volume up to 99.9999 L (ON/OFF selectable) |
| Current Value Indication | Input current displayed in ANA.V / ANA.P modes |
| Calibration | Supported |
| Maximum Flow Rate Setting | Stroke rate: 0.1–100.0%, 1–360 spm |
| AUX Flow Rate Setting | Stroke rate: 0.1–100.0%, 1–360 spm |
| Anti-Chattering | Selectable pulse recognition time to reduce noise effects |
| Logic Selection | Normally Open / Normally Closed selectable for I/O |
| Units | mL/min, L/h, GPH (each can be enabled or disabled) |
| Data Logging | Total flow volume, total shots, OUT1 ON time, total power-on time, operation time, software version |
| Pulse Input | Dry contact or open collector |
| Analogue Input | 0–20 mA DC (input resistance: 220 Ω) |
| STOP / Pre-STOP Input | Dry contact or open collector, 2-step contact (level sensor) |
| AUX Input | Dry contact or open collector |
| Interlock Input | Dry contact or open collector |
| Output – OUT1 | Open collector (photo-coupler), 24 VDC, 30 mA |
| OUT1 Alarm Functions | spm, STATE, STOP, Pre-STOP, Interlock, Batch Complete (enable/disable selectable) |
| Auxiliary DC Power | 12 VDC, 30 mA |
| Power Supply Voltage | 100–240 VAC, 50/60 Hz |
| Proportional Setting (Current) | 2-point setting: 0.0–20.0 mA to max flow rate or 0–100% stroke rate |
| Proportional Setting (Pulse) | 2-point setting: 0.0–500 Hz to max flow rate or 0–100% stroke rate |
| Automatic Calculation | Calculates output capacity per shot and displays flow rate |
Q & A
EWP Series Metering Pump Q & A
Downloads
Download Walchem EWP Series Metering Pump Brochure
Download Walchem EWP-L Series Specification Sheet
Download Walchem EWP-R Series Specification Sheet
Talk to one of our process control experts today at (855) 737-4714 or fill out our online form to learn more.