Oriflow Cobra User manual

© Copyright 2018 ORIFLOW LLC
Operating Instructions for
Cobra and Lynx
Duct Leakage Testers

Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
1
Links to Online Help
(QR Code)
Video – Commercial Duct Leakage
Testing
Online Technical Library
Online Max Leakage Calculator
(SMACNA Leakage Class)
Online Max Leakage Calculator
(% Allowable)

Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
2
Table of Contents
Introduction
Introduction ……………………………………….………………………….…………… 3
Safety Precautions
Safety Precautions ………… READ FIRST! ……….….……………….……………… 3
Prior to Testing
Are You Using the Correct Tester? …………………………………….…...…………. 4
System Preparation …………………….……………….…………….……...….……… 4
Power Requirements …………………………………....…………….……...….……… 4
Extension Cord Requirements ………………………....…………….……...…………. 5
Flex-Duct Length ………………………………………...…………………….……...…. 5
Determining Maximum Allowable Leakage ….………..……………...…….….……… 5
FREE Oriflow duct test summary form (SMACNA or DW/143) ………….….………. 5
Determining Which Orifice Plate to Use ……………....……………..……..…………. 6 - 7
Duct Leakage Test Setup and Procedure
Install Orifice Plate and Upper Tube Section ……………………………..………..…. 8 - 9
Connect Flex-Duct to Orifice Tube ………………........…………….……...….……… 9
Connect Flex-Duct and Static Pressure Tap to Duct System ………….……………. 10 - 11
Duct Leakage Test Setup (SUPPLY) ………………….……………..……..…………. 12
Duct Leakage Test Setup (RETURN/EXHAUST) …………………..……..…………. 13
Zeroing Pressure Gauges ……………………………………………..……..…………. 14
Avoiding Over-Pressurization …………………………..……………...…….…………. 15
Obtaining System Test Pressure ……………………………………...…….…………. 15 - 16
Determining Leakage Rate……………………………………………..….….…………. 16 - 17
Troubleshooting
Can’t obtain system test pressure (DUCT PRESSURE TOO LOW) …………….…. 18
Can’t obtain system test pressure (DUCT PRESSURE TOO HIGH) …….……….… 19
Zero reading on ORIFICE PLATE gauge ……………..…………………........……….. 19
ORIFICE PLATE gauge reading maxed out ………......……………...….…....………. 20
GFCI/GFI trips …………………………………………………………………………….. 20

Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
3
Introduction
These operating instructions are for ORIFLOW models COBRA and LYNX air leakage testers. Take
pride in knowing that you have purchased the best air leakage tester on the market. It is no secret that
Oriflow manufactures the highest quality testers, and has unparalleled customer service and technical
support.
The orifice plates available for your duct leakage tester are constructed from laser-cut 0.063-inch
stainless steel and do not require recalibration for 5 years. Note the authority having jurisdiction may
override this requirement, and if so, Oriflow has reasonable rates for re-calibrating orifice plates
manufactured by Oriflow.
Safety Precautions
Before operating your tester, read the following safety precautions:
DO NOT operate the tester in the rain,
DO NOT operate the tester while it is near or in water,
DO NOT operate the tester with a damaged electrical cord or plug,
DO NOT remove the inlet safety screen,
DO NOT touch the blower wheel when the unit is plugged in,
DO NOT look into the discharge end of the tester when the unit is plugged in,
DO NOT use the tester as a ladder or step stool,
DO NOT allow children near the tester,
DO use an extension cord of the proper gauge (see Table 2),
DO use the proper voltage and line frequency listed on the motor nameplate,
DO lock the caster when the tester is positioned horizontally,
DO use the tester on level ground,
DO secure the tester when transporting it,
DO wear proper hearing protection, safety glasses and work gloves,
DO seek assistance when lifting the tester (e.g., loading onto truck, going up or down stairs).

Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
4
Prior to Testing
Are you Using the Correct Tester?
See Table 1 for the maximum capacity for each duct tester when using the largest orifice plate.
Table 1 – Duct Leakage Tester Capacities


Model
MaximumLeakageCapacity(cfm)*
SystemTestPressure(in.wg.)
0.101246 7 8 9 101214 16
Lynx570
cfm
550
cfm
540
cfm
455
cfm
290
cfm
160
cfm——————
Cobra680
cfm
650
cfm
645
cfm
600
cfm
465
cfm
405
cfm
350
cfm
250
cfm————
Panther1400
cfm
1350
cfm
1320
cfm
1210
cfm
1065
cfm
970
cfm
875
cfm
875
cfm
615
cfm
270
cfm——
Rhino1700
cfm
1630
cfm
1550
cfm
1420
cfm
1330
cfm
1255
cfm
1185
cfm
1185
cfm
1035
cfm
895
cfm
660
cfm
480
cfm
* Using the largest sized orifice available for the model listed.
System Preparation
Cap off all ends of system using clear plastic and duct tape or sheetmetal duct end caps. Make sure
you test the part of the duct system that leakage testing is required. Usually, this is from the system fan
up to, but not including, the VAV boxes (terminal units). Refer to the engineer's specifications and all
applicable codes and test standards.
Power Requirements
Do you have an adequate power supply for your tester (see Table 2)?
Table 2 – Tester Amp Draw
Tester Model Voltage Flow Control
Option Full Load Amps
Lynx 115 Slide Gate 12.7
Cobra 115 Slide Gate 12.8
Cobra 115 VFD 14.0
Cobra 230 Slide Gate 6.4
Cobra 230 VFD 8.0

Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
5
Extension Cord Requirements
If you need an extension cord, is it the proper gauge? See Table 3 below for extension cord
requirements.
Table 3 – Required Extension Cord Wire Gauge
Tester Model Flow Control
Option Voltage Extension Cord
Length (feet) Wire Gauge
Lynx or Cobra Slide Gate 115 10 to 50 14
50 to 100 12
Cobra Slide Gate 230 10 to 50 14
50 to 100 14
Cobra VFD 115 10 to 50 14
50 to 100 12
Cobra VFD 230 10 to 50 14
50 to 100 14
Flex-Duct Length
Make sure you have enough flexible-duct with your tester for the job. Each tester
includes 12.5 feet, which is enough for most applications. Extra lengths of flexible-duct
are available at www.oriflow.com/products.
Determining Maximum Allowable Leakage
To determine the maximum allowable leakage for the project, use ORIFLOW’s free
online programs to make these calculations (www.oriflow.com/programs).
In the U.S., calculations are done for either of the two typical specifications:
1. Percentage of system flow, or
2. SMACNA Leakage Class.
In Europe, Australia and other countries outside of the U.S., the following DW/143 specification is
commonly used:
1. Pressure Classification (Class A, B, C or D)
If the specification uses SMACNA Leakage Class or Pressure Classification, you will need to calculate
the total duct system surface area.
Oriflow has a FREE Adobe test summary sheet that will calculate duct surface area,
leakage, leakage factor, allowable leakage, and Pass/Fail criteria. You can find these
test summary sheets at (www.oriflow.com/freeform). It’s an excellent tool that can be
printed out or emailed to a customer or engineer for submittal.

Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
6
Determining Which Orifice Plate to Use
After determining the allowable leakage at the system test pressure, refer to the following tables for the
capacities of each orifice plate available for the Cobra and Lynx model testers. The proper plate is the
one where the specified allowable leakage falls between the minimum and maximum leakage at the
system static pressure.
For example, if you are testing a system at 4 in.wg. pressure and the maximum allowable leakage is
350 cfm, you will need a 3-inch orifice plate if using the Cobra tester (see Table 6) or a 4-inch plate if
using the Lynx tester (Table 7).
Table 4 – Tester Capacities using the 1-inch Orifice Plate*
System Static
Pressure
(in.wg.)
Minimum
Leakage**
(cfm)
COBRA Tester
Maximum
Leakage
(cfm)
LYNX Tester
Maximum
Leakage
(cfm)
0.10 9 47 37
1 9 44 34
2 9 42 32
3 9 39 27
4 9 36 23
5 9 32 17
6 9 29 15
7 9 24 6
8 9 19 --
9 9 12 --
* If you need to measure lower flow rates, contact us about the
‘low-flow’ orifice plate.
** Recommended minimum based on 0.40 in.wg. across orifice
plate.
Table 5 – Tester Capacities using the 2-inch Orifice Plate
System Static
Pressure
(in.wg.)
Minimum
Leakage**
(cfm)
COBRA Tester
Maximum
Leakage
(cfm)
LYNX Tester
Maximum
Leakage
(cfm)
0.10 34 180 160
1 34 170 150
2 34 165 135
3 34 155 120
4 34 140 105
5 34 125 85
6 34 115 65
7 34 95 25
8 34 75 --
9 34 45 --
** Recommended minimum based on 0.40 in.wg. across orifice plate.

Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
7
Determining Which Orifice Plate to Use (continued)
Table 6 – Tester Capacities using the 3-inch Orifice Plate
System Static
Pressure
(in.wg.)
Minimum
Leakage**
(cfm)
COBRA Tester
Maximum
Leakage
(cfm)
LYNX Tester
Maximum
Leakage
(cfm)
0.10 82 440 375
1 82 420 355
2 82 410 340
3 82 390 320
4 82 375 285
5 82 340 230
6 82 290 170
7 82 245 55
8 82 195 --
9 82 130 --
** Recommended minimum based on 0.40 in.wg. across orifice plate.
Table 7 – Tester Capacities using the 4-inch Orifice Plate
System Static
Pressure
(in.wg.)
Minimum
Leakage**
(cfm)
COBRA Tester
Maximum
Leakage
(cfm)
LYNX Tester
Maximum
Leakage
(cfm)
0.10 175 680 570
1 175 650 550
2 175 645 540
3 175 630 510
4 175 600 455
5 175 545 365
6 175 465 290
7 175 405 160
8 175 350 --
9 175 250 --
** Recommended minimum based on 0.40 in.wg. across orifice plate.

Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
8
Duct Leakage Test Setup and Procedure
Install Orifice Plate and Upper Tube Section
The orifice plate that was determined from the previous section should now be installed with the serial
number facing upwards so the corresponding calibration certificate may be referenced after installation.
Refer to Figures 1 through 4.
Figure 1 – Install Orifice Plate and then Rotate Clockwise
Figure 2 – Rotate Orifice Plate Clockwise until it Locks in Place

Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
9
Install Orifice Plate and Upper Tube Section (continued)
After the orifice plate is locked in place, place the upper tube section over the bolt/wing nut set, rotate
clockwise, and tighten wing nuts (Figures 3 and 4).
Figure 3 – Install Upper Tube Section and Rotate Clockwise
Figure 4 – Tighten Wing Nuts after Rotation