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®
Surelock-B
FOREMOST IN AIR FILTRATION
General
Surelock-B Side Access HEPA Filter Housings are
designed to accept all gasket-seal HEPA filters. They
are all-welded factory-assembled flanged units suitable for installation in a duct on the downstream side
of an air handling unit.
Housings guarantee filter system efficiency equal to
the efficiency of the individual filters. Optional prefilter
tracks are designed to accommodate 2 in. pleated
panel filters with efficiency ranges up to 50% per
ASHRAE Standard 52.1 dust-spot test methods. Both
prefilters and primary HEPA filters are serviceable
through gasketed access doors.
Options
• Prefilter tracks
• Double-walled insulation on doors only or on the
entire housing
• Aluminum or 304 stainless steel housing
construction
• Modifications for high temperature (400 °F continuous, 500 °F intermittent duty)
• Swing-arm assemblies for 6 in. deep HEPA filters
Bolt Lock HEPA Filter Housing
Bulletin PB1603-1206
Construction
Housings are 27 in. deep in the direction of air flow
and are constructed of 14 ga. galvanized steel.
Upstream and downstream outwardly-turned flanges
are furnished for attachment to the ductwork. Each
HEPA filter is secured in place by four positivepressure spring-loaded swing-arm assemblies which
maintain continuous pressure on the filter gasket
against the sealing surfaces.
Optional prefilter tracks are galvanized steel furnished
with a pile gasket. Hinged/removable access doors
are furnished with rubber sealing gaskets and positive-pressure adjustable latches with easy-grip knobs
on the air entering and the air leaving sides to create
an airtight seal. Metal-to-metal joints are welded to
ensure a leak-proof assembly at + 8 in. w.g. internal
pressure.
Versatility
Surelock-B Housings are designed to accommodate
Alpha 95 filters with a DOP efficiency of 95% and
Alpha Cell and Alpha 2000 filters with DOP efficiencies of 99.97%, 99.99% and 99.999%. Standard
housings will accept nominal 12 in. deep 24 in. x 24
in. and 24 in. x 12 in. filters from one filter high and
one filter wide to four filters high and six filters wide. If
large units are not practical to install, smaller units are
available with modifications to facilitate stacking.
Important Features
• Units are constructed of durable 14 ga.
galvanized steel
• All metal-to-metal joints are welded for
leak-tightness at + 8 in. w.g. internal pressure
• Prefilter tracks and doors are fully gasketed
• Positive-pressure adjustable door latches
create an air-tight seal
• Spring-loaded swing-arm assemblies hold
HEPA filters to sealing surface
• Access doors are hinged/removable for easy
service
Flanders Filters - Foremost in Air Filtration
Toll Free: 1-800-637-2803
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Cfm Capacities and Dimensions
Using Standard Alpha Cell and Alpha 2000 High Capacity HEPA Filters
Height
Code
05H
10H
15H
20H
25H
30H
35H
40H
Overall
Flange
Height
(in.)
15-5/6
27-5/16
39-5/16
51-5/16
63-5/16
75-5/16
87-5/16
99-5/16
Initial
PD
(in. w.g.)
1.0
1.0
1.3
1.0
1.0
1.3
1.0
1.0
1.3
1.0
1.0
1.3
1.0
1.0
1.3
1.0
1.0
1.3
1.0
1.0
1.3
1.0
1.0
1.3
Face
Velocity
(fpm)
300
375
500
300
375
500
300
375
500
300
375
500
300
375
500
300
375
500
300
375
500
300
375
500
Filter
Type
(Note 4)
Std
HC
HC
Std
HC
HC
Std
HC
HC
Std
HC
HC
Std
HC
HC
Std
HC
HC
Std
HC
HC
Std
HC
HC
Width Code
10W 15W 20W 25W 30W 35W 40W 45W 50W 55W 60W
Overall Flange Width (inches)
26 39-9/16
600
750
1000
1200
1500
2000
1800
2250
3000
2400
3000
4000
3000
3750
5000
3600
4500
6000
4200
5250
7000
4800
6000
8000
1800
2250
3000
3600
4500
6000
5400
6750
9000
7200
9000
12000
--
--
--
--
51-9/16
1200
1500
2000
2400
3000
4000
3600
4500
6000
4800
6000
8000
6000
7500
10000
7200
9000
12000
8400
10500
14000
9600
12000
16000
65-1/8 77-1/8
1800
2250
-3000
3000
3750
5000
6000
7500
10000
9000
11250
15000
12000
15000
20000
3600
4500
6000
5400
6750
-9000
7200
9000
12000
9000
11250
--
15000
10800
13500
18000
12600
15750
--
21000
14400
18000
24000
90-11/16
--
4200
5250
7000
--
8400
10500
14000
--
12600
15750
21000
--
16800
21000
28000
102-11/16 116-1/4 128-1/4 141-13/16
2400
3000
4000
4800
6000
8000
7200
9000
12000
9600
12000
16000
12000
15000
20000
14400
18000
24000
16800
21000
28000
19200
24000
32000
--
5400
6750
9000
--
10800
13500
18000
--
16200
20250
27000
--
21000
26250
35000
--
6000
7500
10000
9000
11250
15000
12000
15000
20000
15000
18750
25000
18000
22500
30000
21000
26250
35000
24000
30000
40000
--
6600
8250
11100
--
13200
16500
22000
--
19800
24750
33000
--
26400
33000
44000
153-13/16
7200
9000
12000
10800
13500
18000
14400
18000
24000
18000
22500
30000
21600
27000
36000
25200
31500
42000
28800
36000
48000
--
Notes:
1. Height and Width Code: The first numeral represents the number of 24 in. x 24 in. filters high or wide. If 24 in. x 12 in.
filters are also used in the height width, the second numeral is “5”.
2. Standard housing depth is 27 in. with or without a 2 in. prefilter track.
3. For capacities and pressure drop other than those shown, ratio the face velocities.
4. Capacities shown are based on Standard (Std) and High Capacity (HC) 99.97% and 99.99% Alpha Cell filters nominal 12
in. deep and actual face sizes of 24 in. x 24 in. and 24 in. x 12 in.
5. Use Surelock Housings with Alpha 95 filters rated at 500 fpm and 1.0 in. w.g. initial pressure drop.
Model Number Development
Example: The number SLB220H30WX represents a Surelock
B housing with 2 in. prefilter track, 2 filters high and 3 filters
wide. The letter X indicates that special features are required.
Prefix SLB stands for Surelock B style housing
Prefilter track designation. Nothing goes here if no prefilter track
is desired. Insert a 2 for a 2” prefilter track or a 4 for 4” prefilter track
Height and Width code: The first numeral of each section represents the
number of 24”x24” filters high or wide. If a 24”x12” filter is used to complete the height or width, the second numeral of section will be “5”.
For special features or sizes, end with the suffix “X” and describe them.
SLB 2
20H
30W
X
2
Flanders Filters - Foremost in Air Filtration
Toll Free: 1-800-637-2803