
Duratherm* HWS Series
Hot Water Sanitization Pure Water Elements
Description and Use
The Duratherm* HWS Series includes RO, NF and
UF membrane elements. This Series is specifically
designed to maximize the benefits of hot water
sanitization for industries relying on chemical free
sanitization for product quality and/or industry
compliance standard.
Separation system sanitization protocol is performed via periodic exposure to temperature as
high as 195°F (90°C) at minimum feed pressure to
kill microorganisms by denaturation and coagulation of the proteins chains.
The Duratherm HWS RO and HWS NF are suitable
for separation systems purifying water at temperature up to 122°F (50°C) in low crossflow environment and no suspended solids.
This Series includes a variety of size 8”, 4” and 2.5”
diameters. All element constructions include
Durasan* Cage outer wrap, Polysulfone ATD and
central tube.
Features and Benefits
• Prevent bio-fouling development
• No disposal costs
• 100% wet testing Quality Assurance
• Durable construction
• Sanitization on the permeate side
Markets
• Food / Beverage
• BioPharm
• Electronics
• Chemical
Table 1: Element Specification
Membrane A-Series, Thin-film membrane (TFM*)
a=HWS RO-HR, b=HWS RO, c=HWS NF, d=HWS UF
Model
Duratherm HWS RO2540HR
Duratherm HWS RO4040HR
Duratherm HWS RO8040HR
Duratherm HWS RO2540
Duratherm HWS RO4040
Duratherm HWS RO8040
Duratherm HWS RO8040, WET 65 (14.8) 9,200 (34.8) 99.0%
Duratherm HWS SG80402 60 (13.62) 8,600 (32.6) 98.5%
Duratherm HWS NF4040
Duratherm HWS NF8040
Duratherm HWS UF8040 65 (14.8) -- 10,000 Da
1
Testing conditions: 2,000ppm NaCl solution at 225psig (1,550kPa) operating
pressure, 77°F, pH7.5 and 15% recovery before any hot water sanitization.
2
Testing conditions: 500ppm NaCl solution at 115psig (790kPa) operating
pressure, 77°F, pH7.5 and 15% recovery before any hot water sanitization.
3
Testing conditions: 2,000ppm MgSO4 solution at 110psig (760kPa) operating
pressure, 77°F, pH7.5 and 15% recovery before any hot water sanitization
4
Average salt rejection after 24 hours operation. Individual flow rate may vary
+25%/-15%. Final permeate flow rate is subject to variations in the heat treatments. In most cases, the permeate flow rate after heat treatments will stabilize at 30-50 percent below the nominal flowrate before heat treatment. For a
conservative design, consider a permeate flow reduction of 50%.
D-Series, Thin-film membrane (TFM*)c
P-Series, Polyethersulfoned
Maximum
Crossflow
gpm (m3/h)
1,4
4 (0.9) 620 (2.3) 99.5%
1,4
20 (4.5) 2,300 (8.7) 99.5%
1,4
65 (14.8) 9,900 (37.5) 99.5%
2,4
4 (0.9) 760 (2.9) 99.0%
2,4
20 (4.5) 2,200 (8.3) 99.0%
2,4
65 (14.8) 9,200 (34.8) 99.0%
3,4
20 (4.5) 2,100 (7.9) 98.6%
3,4
65 (14.8) 8,500 (32.2) 98.6%
a,b
Average
permeate flow
gpd (m3/day)
Average salt
rejection
/ MWCO
Find a contact near you by visiting www.gewater.com and clicking on “Contact Us”.
* Trademark of General Electric Company; may be registered in one or more countries.
©2014, General Electric Company. All rights reserved.
FS1270EN.doc Jan-14

Model
Duratherm HWS RO2540HR 25 (2.3) Cage 1263600
Duratherm HWS RO4040HR 88 (8.2) Cage 1263435
Duratherm HWS RO8040HR 355 (33.0) Cage 1263599
Duratherm HWS RO2540 25 (2.3) Cage 1228430
Duratherm HWS RO4040 85 (7.9) Cage 1228459
Duratherm HWS RO8040, WET 355 (33.0) Cage 3048232
Duratherm HWS RO8040 355 (33.0) Cage 1228481
Duratherm HWS SG8040 390 (36.2) Cage 1207613
Duratherm HWS NF4040 88 (8.2) Cage 1263437
Duratherm HWS NF8040 355 (33.0) Cage 1262377
Duratherm HWS UF8040 380 (35.3) Cage 1263602
Active area
ft2 (m2)
Outer wrap Part
number
Table 3: Temperatures
Do not exceed 20 GFD (34LMH) in any circumstances
Model
Duratherm HWS RO HR 122°F (50°C) 122°F (50°C) 194°F (90°C)
Duratherm HWS RO 122°F (50°C) 122°F (50°C) 194°F (90°C)
Duratherm HWS SG 122°F (50°C) 122°F (50°C) 194°F (90°C)
Duratherm HWS NF 122°F (50°C) 113°F (40°C) 194°F (90°C)
Duratherm HWS UF 122°F (50°C) 122°F (50°C) 194°F (90°C)
Maximum
operating
temperature
Maximum
cleaning
temperature
Maximum
sanitization
temperature
Table 4: Pressures and operating parameters
Figure 1a: Element Dimensions Diagram (Female) – 4040 &
8040
Figure 1b: Element Dimensions Diagram (Male) - 2540
Table 2: Dimensions and Weight
Dimensions, inches (cm) Boxed
Model1
HWS 2540 Models
HWS 4040 Models
HWS 8040 Models
1
A includes the interconnector.
2
Internal diameter unless specified OD (outside diameter).
3
The element diameter (dimension C) is designed for optimum performance in
GE pressure vessels. Other pressure vessel dimension and tolerance may result
in excessive bypass and loss of capacity
A B2 C3
40.0
(101.6)
40.01
(101.6)
40.0
(101.6)
0.75
(1.90) OD
0.625
(1.59)
1.125
(2.86)
2.4
(6.1)
3.9
(9.9)
7.9
(20.1)
Weight
lbs (kg)
4
(1.8)
9
(4.1)
29
(13.2)
Model
Duratherm
HWS RO HR
Duratherm
HWS RO
Duratherm
HWS SG
Duratherm
HWS NF
Duratherm
HWS UF
1
Do not operate at T>50°C (Sanitizing only)
Max operating pressure Typical
41–122°F (5–50°C)
600psi (4,137kPa)
600psi (4,137kPa)
600psi (4,137 kPa)
600psi (4,137kPa)
600psi (4,137kPa)
applied
pressure
225psi
(1,551kPa)
225psi
(1,551kPa)
225psi
(1,551kPa)
110psi
(760kPa)
80psi
(552kPa)
Rec.
element
recovery
<15%
<15%
<15%
<15%
<15%
Typical
operating
flux
10-18GFD
(17-31LMH)
10-18GFD
(17-31LMH)
10-18GFD
(17-31LMH)
10-18GFD
(17-31LMH)
10-25GFD
(17-40 LMH)
Table 5: Operating and CIP parameters
pH range
Model
Duratherm HWS RO HR 4.0-11.0 2.0-11.5
Duratherm HWS RO 4.0-11.0 2.0-11.5
Duratherm HWS SG 2.0-10.0 1.0 – 10.5
Duratherm HWS NF 3.0-9.0 2.0-10.5
Duratherm HWS UF 4.0-11.0 2.0-11.5
1
Dechlorination recommended
Continuous
Operation
Clean-in-
Place (CIP)
Chlorine
tolerance
500 ppm-
hours1
500 ppm-
hours1
500 ppm-
hours1
500 ppm-
hours1
5,000+ ppm-
days
Feed
water
NTU < 1
SDI < 5
NTU < 1
SDI < 5
NTU < 1
SDI < 5
NTU < 1
SDI < 5
NTU < 1
SDI < 5
Page 2 FS1270EN

Hot Water Sanitization
Recommendations
For optimal performance, Duratherm HWS elements should always be cleaned using approved
CIP procedures and flushed with fouling free water before the sanitization process. Feed pressure
during sanitization should not exceed 40psi
(275kPa) and the crossflow should not incur a
pressure drop greater than 2psi (14kPa) per element. Heating rate to sanitizing temperature and
cool down should not be faster than 5°C
(41°F)/minute. Maximum sanitization temperature
is 90°C (194°F).
Loss of permeate flow after repeated
90°C (194°F) sanitization cycles
It is almost impossible to exactly predict the percentage of permeate flow rate lost from the high
temperature sanitations, which among other factors depends on:
1) Rate of temperature increase and decrease.
Salt Rejection
Figure 2: NaCl rejection for HWS RO HR element
2) Presence of other species like organics, ionic
and metallic compounds that could locally decrease or increase the temperature at the surface of the membrane.
3) Feed flow rate and specifically the heat trans-
fer rate to the membrane surface.
4) The thickness and geometry of the feed spac-
er used.
At optimum conditions measured in controlled
environment with deionized water, between 30%
and 50% of the original permeate flow rate was
lost before the element performance had stabilized after repeated heat treatments (over 90% of
this flow reduction occurred during the first heat
treatment). With the loss of permeate flow rate,
the salt rejection increases. The rate of cooling
and heating was not more than 5°C (41°F) per minute, and the differential pressure drop per element did not exceed 2 psi.
Pilot testing based on the criteria noted above will
give the best operating parameters for any specific application.
Figure 3: NaCl rejection for HWS RO element
Figure 4: MgSO4 rejection for HWS NF HF element
FS1270EN Page 3

Pressure Drop
Figure 5: Pressure drop for HWS 2540 elements
Figure 6: Pressure drop for HWS 4040 elements
Net Driving Pressure
Figure 8: Net Driving Pressure for HWS RO HR elements
Figure 9: Net Driving Pressure for HWS RO elements
Figure 7: Pressure drop for HWS 8040 elements
Page 4 FS1270EN
Figure 10: Net Driving Pressure for HWS NF HF elements