Data Sheet GAS-4105g

AquaSep® Plus L /L Coalescer
System Effectively Separat es
Water from Petroleum Productsand Chemicals
Introduction
Entrained water in liquid hydrocarbons and chemicals canbe a problem. This is particularly true for fuels that containhigh concentrations of surfactants which are readilypresent in hydrocarbons and chemicals (see below).
Surfactants make water removal difficult for conventionalliquid/liquid coalescers and other water separationequipment because they lower the interfacial tension
between the water and the continuous phase fluid.
The same problem can occur when attempting toseparate oil from water. The presence of surfactantsalso leads to disarming of the coalescer. Pall’s
AquaSep Plus coalescer will efficiently separate waterfrom a hydrocarbon stream without disarming.
Common Sources of Surfactants in
Hydrocarbon and Chemical Processes• Sulfur compounds• Organic acids• Well treating chemicals• Anti-static chemicals• Detergents• Corrosion inhibitorsof the coalescer assembly to properly control
particulate matter in the liquid stream. Installing aprefilter significantly extends the life of the coalescerand reduces particulate concentration in the filter
effluent to meet solids specifications.

• Chemical additives
Coalescer Information
The Pall AquaSep Plus coalescer is a multiple stagesystem. It first removes particulate matter, thencoalesces and separates the dispersed phase liquidfrom the continuous phase liquid.
For removal of water from hydrocarbons, the AquaSep
Plus coalescer will remove entrained water to a level of
below 15 ppmv over a wide range of conditions:• Inlet water concentration as high as 3% water byvolume (i.e., 30,000 ppmv.)• Interfacial tension as low as 3.0 dyne/cm
For removal of oil from water, the AquaSep Plus
coalescer will remove free oil from water over a wide
range of conditions in the horizontal configuration.
Liquid/ Liquid Coalescer Elements
Stage 1: Prefiltration
Due to the fine pore structure of this coalescer medium,
Pall recommends that a prefilter be installed upstream

To maximize the service life of AquaSep Plus
coalescers, each coalescer is constructed with an
integral prefilter.
Stage 2: Coalescence
The hydrocarbon and water mixture enters the coalescing
element and flows inside to outside (see Figure 1). This iswhere small droplets of dispersed phase liquid cometogether, or coalesce, as the mixture moves through thedepth of Pall’s specially formulated coalescer medium.
Stage 3: Separation
In separating water from fuel, water-free fuel and large
water droplets flow toward the separator located directly
below the coalescer stage. Flow is outside to inside (seeFigure 1). The separator medium is hydrophobic, which
prevents water from entering the separator. Only waterfree fuel flows through the separator. Water and fuel areremoved by separate drain connections.
In separating oil from water, a settling zone is designed
downstream of the coalescer. In the settling zone, thelarge coalescer droplets are separated due to gravity(see Figure 2).

Benefits
Continuously Efficient in Liquid Separation andParticle Removal for Improved Fluid Quality and Value
The effective liquid separation and the particulateremoval abilities of the AquaSep Plus coalescer systemsignificantly reduces off-spec product incidents, thereby
saving reprocessing and transportation costs.
Low Cost Liquid Separation and Solids RemovalDue to AquaSep Plus coalescer’s longer life and superiorliquid separation efficiency, the overall cost of liquid
separation is low especially when compared to other lessefficient methods. The integral prefilter within the AquaSep
Plus coalescer maximizes element service life.
Does Not Disarm; Increases Service Life
Pall’s specially formulated medium coalescer contains
no glass fiber and does not disarm in the presence ofsurfactants. This results in longer service life thanconventional coalescers. The prefilter stage removes
particulates and also extends the filter service life.

Unique Stack Design
Pall’s coalescer element is stacked on top of a separator
element. This design optimizes the flow distribution fromthe coalescer to the separator, ensuring that eachseparator has an equal flow. In conventional two-stagesystems, the separators are located at different distancesfrom the coalescer, causing an unequal distribution of flow
to the separator. These conventional two-stage systems
require several coalescer elements for each separator.
Pall’s stack design results in overall smaller assembly size
and a longer coalescer/separator life.
Fluid Compatibility
Pall’s AquaSep Plus liquid/liquid coalescer is compatible
with refined products including:• All gasolines• Diesel• Kerosene• Lube oils
• Aromatics

High Performance Design Results inSmaller Assembly Size
The high performance AquaSep Plus coalescer stack
design promotes an even flow distribution permitting ahigh rate of flow. As a result, fewer coalescer cartridges
are required to efficiently remove water from fuel. Thisresults in a small economic assembly size.

• Petrochemicals• LPG

Continuous phase
contaminant free

Pall AquaSep
Plus coalescerPallAquaSep
Plus stackPallprefilter

Coalescerwith integral
prefilter

Pallprefilter

Liquidcontaminant(dispersedphase) out

Separator
Fuel out

Fuel in withwater and Fuel andwatersolids
without dirt

Waterout

Figure 1: AquaSep Plus Liquid/Liquid Coalescer
SystemLower Disposal and Maintenance Costs
The long, useful life of the AquaSep Plus cartridges, isobtained from Pall’s specially formulated non-disarming
high voids volume medium that is properly protectedby Pall prefilters. Overall results are fewer cartridgechangeouts for low maintenance and disposal costs.

Fuel orchemical withliquid or solid
contaminants

Fuel or chemicalwith liquidcontaminants
without dirt

Figure 2: Pall AquaSep Plus Liquid/Liquid Separation
System with Coalescer in a Horizontal
Housing
Mechanism of Coalescing with
Conventional Glass Medium
One of the biggest operational problems for conventionalliquid/liquid coalescers is disarming. When a liquid/liquidcoalescer is performing efficiently, water molecules bondwith components on the glass fiber called a silenol
functional group. The water molecules that collect on theglass fiber coalesce with incoming water molecules toform a large droplet, which will eventually become heavy
enough to drain from the coalescer. In an efficiently
operating coalescer, once a droplet has fallen from anactive site, the coalescing process repeats (see Figure 3).
Step 1

Step 2

Fuel contains
small waterdroplets

Water
molecules
bond to silenolgroup locatedon glass fiber

Glass
Fiber

Step 4

Water droplets
coalesce withbondeddroplets to form
larger droplets

Large water
droplets drain;water moleculesbond to open
silenol sites
Glass
Fiber

Glass
Fiber

To Drain

Disarming occurs when surfactants bond with thesilenol group. The silenol group has a greater affinity
for surfactant molecules than for water molecules. As
the surfactant molecules bond to the glass fibers, thewater molecules pass quickly through the medium (seeFigure 4). This greatly reduces water removal efficiency,increasing the probability of a product quality problem,and short coalescer service life, which, in turn, results infrequent changeout and increased disposal costs ofcoalescer filter elements.
Surfactants

Step 2
Silenol groupon glass fiber
has affinity forsurfactants
over water

Fuel contains
small water
droplets andsurfactants

Glass
Fiber

Glass
Fiber

Step 3
Water droplets
pass throughglass fiber;coalescer isdisarmed andmust be replaced

Glass
Fiber

Figure 4: Mechanism for Disarming

66°C/150°F

Initial Pressure Drop:

0.14 bard/2 psid

Recommended Changeout:

1.03 bard/15 psidPart
NumberFigure 3: Mechanism for Coalescinge

Step 1

Maximum Temperature:

Ordering Information
Glass
Fiber

Step 3

Performance Claims and Specifications

Description

Outer Diameter(cm/in)Length(cm/in)LCS2B1AH

AquaSep Plus
Coalescer

9.53/33⁄450.8/20

LCS4B1AHAquaSep Plus
Coalescer

9.53/33⁄4

101.6/40

LSS2F2H

Separator

9.53/33⁄450.8/20

Please call your Pall representative to confirm compatibility
for a specific application.

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and AquaSep are trademarks of Pall Corporation. ® Indicates ais a service mark of Pall Corporation.