Walchem EWN Data sheet

Metering Pumps

EWN-R Series Electromagnetic Metering Pumps

The EWN-R Series electronic metering pumps offer superior high speed
dosing capability with more standard features. The flexibility of the EWN-R
pump enable it be integrated into virtually any chemical feed application using
a universal-voltage, digital controller with an expanded set of control features.
Superb valve performance and advanced solenoid engineering combine to
make a highly precise pump for the most demanding applications.

EWN pumps have outputs to 6.7 GPH (25.2 L/h) and a maximum pressure
of 290 PSI (20 bar). The high speed of operation results in high resolution
chemical feed and long service life. Quiet and compact, the EWN pumps
prime in seconds and hold prime reliably.

High Speed Performance

E-Series pumps operate up to 360 strokes-per-minute with adjustments in 1 spm increments, providing high resolution
chemical feed. Adjustable stroke length further increases the ability to refine the output, making the E-Series one of the
most versatile solenoid metering pumps on the market.

Multi-function Digital Controller

The controller in the EWN-R pump provides for flexible pump control including scalable Analog control, Digital Input
with both Multiply and Divide capability, external stop control, or simple speed and stroke length control. Display
can be adjusted between flow rate units or % speed for easy-to-read output and quick adjustment. The controller is
universal voltage so it can be used anywhere in the world.

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.

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. This superior check valve design guarantees fast priming and reliable performance.

Flexible Connections

A removable tubing insert provides flexibility of tubing sizes and eliminates twisting of the
tubing during connection. A threaded insert can be used in place of the tubing adapter to
easily convert any connection to NPT.

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).

Specifications

(10.5)

Model Identication

Series symbol
EWN-R series

Diaphragm diameter

Eective diaphragm dia.

09: 8mm 11: 10mm 16: 15mm
21: 20mm 31: 30mm 36: 35mm

Drive unit symbol

Average power consumption
B: 20W C: 24W

EWN - B 11 VC U R

Wet-end material symbol

For details, see the table of materials.

Tubing Connection
Blank: 1/4” x 3/8” (B09, B11, B16, B21, C16, C21)

3/8” x 1/2” (B31, C31, C36)
1/4” FNPT (SH/FC, FC also supplied with tubing ttings)

(For other options, contact your distributor)

Wet End Materials

Pump Head Diaphragm

VC

VE EPDM EPDM

VF PTFE EPDM EPDM

PC

PE EPDM EPDM

PA PCTFE AFLAS®

FC

TC FKM FKM

TA

SH 316SS

CE Alumina ceramic EPDM Ethylene propylene diene monomer
FKM Fluoroe lastomer GFRP P Glass fiber reinforced polypropylene
PTFE Polytetrafluoroethylene PVC Polyvinylchloride (translucent)
PCTFE Polychlorotrifluoroethylene HC Hastelloy C276
PVDF Polyvinylidenefluoride 316SS 316 Stainless Steel

PVC

GFRPP

PTFE +EPDM

PVDF

Valve

Balls

CE

CE

HC 316SS PTFE

Valve Seat

FKM FKM

FKM FKM

PCTFE PTFE

PCTFE AFLAS®

O-ring

Seal

Gasket

PTFE

Controller
function code
R: Standard type

Power code
U: 115V US plug
2: 230V US plug

Valve

O-ring

Diaphragm
Pump head

Gasket

Valve seat

Options
C: High compression version + ADV

(available on 09-21-VC/VE)
H: High pressure version (250 PSI)
(available on B11/C16-PC/PE/PA/SH)
H2: High pressure version (290 PSI)
(available on B11-PC/PE/PA/SH)
V: High Viscosity version
(available on C31-PC/P6)
A: Auto Degassing valve included
(available on 11-21-VC/VE)
M: Multifunction valve included
(available on all models except FC/SH
or with other options)
N: No Manual Air Vent Valve (SH only)

Pump Specications (Standard pumps and pumps with MFV)

Model B11 B16 B21 B31 C16 C21 C31

Maximum output
capacity

Maximum rated
discharge pressure

Maximum useable
pressure

Stroke rate % (spm)

Stroke length rate % (mm)

Note 1: Maximum output capacity shown is at Maximum Rated Discharge Pressure (stroke length 100%, stroke rate 100%) and increases as a discharge pressure reduces.
Note 2: Maximum Useable pressure rating is the maximum useable capability of the pump. Maximum output capacities may be lower than published at pressures
higher than Maximum Rated Discharge Pressure. Maximum pressure of PVC type is 174 PSI. Please contact your distributor for more information.
Note 3: The performance is based on pumping clean water at ambient temperature at rated discharge pressure and voltage.
Note 4: Liquid temperature: PVC liquid ends: 14 to 104°F (-10 to 40ºC) GRFPP/PVDF/SS liquid ends: 14 to 140°F (-10 to 60ºC)
Note 5: Ambient temperature: 32 to 122°F (0 to 50°C) Relative humidity: to 85% (non-condensing)
Note 6: All pumps include a manual air vent valve except FC/SHN/HV models. All pumps include one foot valve, injection valve, 20 ft. of PE tubing and ceramic
weight except for SH/H2/HV models.

Input/Output Connectors (Sold Separately):
E90495 5-pin connector: Use for Analog, Pulse & AUX inputs + Output Relay on EWN-R
E90496 5-pin reverse key connector: Use for Stop & Pre-Stop inputs on EWN-R

GPH

mL/min

mL/shot

PSI

PSI

0.6 1.0 1.6 3.2 1.3 2.1 4.3 6.7 6.5

38 65 100 200 80 130 270 420 410

0.02-0.11 0.04-0.18 0.06-0.28 0.11-0.56 0.04-0.22 0.07-0.36 0.15-0.75 0.23-1.17 0.23-1.14

150 105 60 30 150 105 50 30 30

203 116 73 30 174 116 50 30 30

0.1 to 100 (1 to 360)

20 to 100 (0.2 to 1.0) 20 to 100 (0.25 to 1.25)

VC/VE/PC/PE FC/SH/TC

C36