NVE Challenger Series User manual

Owner’s Manual
B250 Tri-Lobe Blower
800-253-5500 |www.natvac.comDesigned. Built. Supported in the USA.
MADE IN THE USA
National Vacuum Equipment, Inc.
National Vacuum Equipment, Inc.
National Vacuum Equipment, Inc.

2| B250 Challenger Series www.natvac.com | 800.253.5500
Weights and measurements are
for reference only.
© 2020 National Vacuum Equipment, Inc.
Revision: 1 (Release) January 2020
No part of this manual may be reproduced without the wrien permission of
National Vacuum Equipment, Inc.
B250 BLOWER
Owner’s Record
Date of Purchase: _________________________
Purchased from: __________________________
Serial Number: ____________________________

B250 Challenger Series | 3www.natvac.com | 800.253.5500 Weights and measurements are
for reference only.
CONTENTS
Introduction ................................................................................. 5
About National Vacuum Equipment, Inc.......................................5
Our History ........................................................................................5
Limited Warranty......................................................................... 6
Warranty.............................................................................................6
Warranty Procedures.......................................................................7
Disclaimer .................................................................................... 7
Condition Of Sales ...................................................................... 7
Safety Instructions...................................................................... 8
Safety Precautions.........................................................................10
B250 Tri-Lobe Blower................................................................. 11
General Blower Operation..............................................................11
Location of Serial Number .............................................................11
Specifications.............................................................................12
Operating Environment................................................................. 12
Operating Limits ............................................................................. 12
Performance.................................................................................... 13
Airflow Control ................................................................................ 13
Sound Control ................................................................................ 13
Rotation and Airflow ...................................................................... 14
Handling ........................................................................................... 15
Preservation .................................................................................... 16
Limitations of Use........................................................................... 17
Installation Considerations.......................................................18
Belt Drive System........................................................................... 19
Drive Sha System ....................................................................... 20
Diesel Engine Precautions........................................................... 20
Direct Coupler Installation & Alignment..................................... 21
Hydraulic Drive................................................................................ 21
Plumbing and Piping ..................................................................... 22
Recommended Accessories..................................................... 22

4| B250 Challenger Series www.natvac.com | 800.253.5500
Weights and measurements are
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Exhaust Silencer............................................................................ 22
Intake Filter..................................................................................... 23
Four-Way Valve............................................................................... 23
Inlet Check Valve ........................................................................... 24
Primary Shuto.............................................................................. 24
Secondary Shuto/Moisture Trap.............................................. 24
Operation ................................................................................... 24
Preliminary Check on Stored Units ............................................ 24
Initial Start Up ................................................................................ 25
Prior To Regular Start Up ............................................................. 25
Operating The Blower.................................................................... 26
Stopping The Blower .................................................................... 26
Cold Weather Operating................................................................27
Maintenance ..............................................................................28
Before Beginning Maintenance .................................................. 28
Procedure for Removal of Pressure Retaining Device............ 28
Four-Way Valve Adjustment ......................................................... 29
Relief Valve Seing Instructions................................................. 30
Pressure Relief Valve .................................................................... 30
Pressure Relief Valve Adjustment Procedure........................... 30
Vacuum Relief Valve....................................................................... 31
Pressure Relief Valve Adjustment Procedure............................ 31
Maintenance Schedule................................................................. 32
Clean Out Procedure If Flooded ................................................. 33
Rebuilding ....................................................................................... 33
Maintenance Notes....................................................................... 34
Troubleshooting ........................................................................ 35
Change Sump Gear Oil ..................................................................37
Approximate Oil Capacities ......................................................... 39
Blower Dimensions Diagram ....................................................... 40
Blower Parts Diagram.................................................................... 41
Blower Parts List............................................................................ 42

B250 Challenger Series | 5www.natvac.com | 800.253.5500 Weights and measurements are
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INTRODUCTION
General Information
About National Vacuum Equipment
Congratulations! You now own a quality vacuum/pressure
blower proudly manufactured in the U.S.A. by National Vacuum
Equipment, Inc. You have not only acquired a superior piece
of equipment from a qualified dealer, you have hired a team of
vacuum experts. We stand ready to work with your dealer to
answer your questions and provide you with the information
necessary to keep your equipment in peak working condition.
Thank you for puing your trust in National Vacuum Equipment.
Our Mission
We are dedicated to the production and wholesale distribution
of quality vacuum system products at a reasonable price, on a
timely basis. We are a “one-stop shop” for manufacturers and
distributors of vacuum equipment.
Our History
National Vacuum Equipment, Inc. was founded in 1980 by Bruce
Luoma. The Company started as a retailer of vacuum pumps.
Soon aer it started, the Company secured the rights to exclusive
distribution of the Baioni vacuum pumps in North America.
This helped the Company to evolve into its current status as a
wholesale supplier. To reach the goal of becoming a full service
supplier of vacuum system components, the Company began
fabrication of its own line of components, purchased and
developed its own line of vacuum pumps and blowers, and began
purchasing for resale, various valves and accessories.
Today, NVE has full service machine, fabrication and powder-
coating shops complete with CNC-controlled production
equipment designed for close tolerance work. The company has a
highly trained sta, all of whom are dedicated to quality.

6| B250 Challenger Series www.natvac.com | 800.253.5500
Weights and measurements are
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LIMITED WARRANTY
Warranty
National Vacuum Equipment, Inc. guarantees that the product
it provides is free of manufacturer defects, including; materials
and workmanship. Equipment must be installed by a trained and
qualified installer according to guidelines established by National
Vacuum Equipment, Inc. Properly installed and maintained product
is warranted for a period of one (1) year subject to the following
conditions:
1. A properly completed warranty registration card must
be received by us within 30 days of sale to end user for
blower sales to be considered warrantable. Or use the
QR code on the right to fill out warranty registration
online (hps://natvac.com/warranty-registration/).
All blowers received for warranty consideration must
retain the original NVE serial number tag.
2. The one (1) year period shall begin the day the product is shipped
from our warehouse, unless we are provided with an authentic copy
of the original resale invoice, in which case the one (1) year period
shall begin at such invoice date.
3. The covered product must be used in an application for which it
was intended. We do not recommend our product for particular
uses or applications.
4. Damage caused by improper use or lack of proper maintenance is
not warrantable.
5. Manufacturer’s liability under this, or any other warranty whether
expressed or implied, is limited to repair of or at the manufacturers’
option, replacement of parts which are shown to have been
defective when shipped.
6. Manufacturer’s liability shall not be enforceable for any product
until National Vacuum Equipment, Inc. has been paid in full for such
product.
7. Manufacturer’s liability for incidental and consequential damage is
hereby excluded to the full extent permied by law.
8. Manufacturer’s liability as stated herein cannot be altered except in
writing signed by an oicer of National Vacuum Equipment, Inc.
9. Certain products provided by National Vacuum Equipment,
Inc. are covered by their respective manufacturers’ warranties
(e.g., engines used in the NVE engine drive packages). These
products are not covered by the National Vacuum Equipment, Inc.
Manufacturers’ Warranty.
10.Equipment must be installed by a trained and qualified installer
according to guidelines established by National Vacuum
Equipment, Inc.

B250 Challenger Series | 7www.natvac.com | 800.253.5500 Weights and measurements are
for reference only.
Warranty Procedures
Should a potential warranty situation arise, the following proce-
dures must be followed:
• Contact your dealer immediately upon the occurrence of the
event and within the warranty period.
• Customer must receive a return goods authorization (RGA)
before returning product.
• All serial-numbered products must retain the NVE serial
number tag to be qualified for warranty.
• Product must be returned to NVE intact for inspection before
warranty will be honored.
• Product must be returned to NVE freight prepaid in the most
economical way.
• Credit will be issued for material found to be defective upon
our inspection, based upon prices at the time of purchase.
DISCLAIMER
The information presented in this owner’s manual is accurate per
the date of publication. National Vacuum Equipment reserves
the right to make product design and documentation material
changes without notice.
Furthermore, National Vacuum Equipment is not obligated
to implement the aforementioned alterations into already
manufactured equipment. Should any discrepancy in
documentation or design arise, contact should be made with
National Vacuum Equipment for clarification. The information
presented in this manual is meant for reference only. This
manual cannot represent every possible application for this NVE
product. Thus, it is the installer and/or end user’s responsibility
to ensure the system is designed, installed, and operated in a
safe manner. Furthermore, this manual is applicable only to the
NVE product(s) documented herein. It is not applicable to the
entire system of which the NVE product is a component of. Thus,
the system designer should be consulted for proper, safe, and
eicient operation of any system containing NVE components.
NVE cannot assume any responsibility for damage and/or injury
resulting from improper system operation.

8| B250 Challenger Series www.natvac.com | 800.253.5500
Weights and measurements are
for reference only.
National Vacuum Equipment considers safety an essential
component in the use of its products. There is no replacement
for proper training of personnel who will be in contact with NVE
products. This manual should be thoroughly read and understood
prior to installing, operating, maintaining, or servicing the NVE
product documented herein. Furthermore, as this NVE product is
only a component in an engineered system, the system designer
and any ailiated documentation should also be consulted.
Equipment safety decals should also be referenced and kept in a
clean, and easily visible condition. Contact NVE for replacement
labels if needed.
This symbol is a “safety aention symbol”
and appears with most safety statements
in this manual. Pay special aention
to these symbols and associated
text as they highlight a hazard that, if
not avoided, can result in equipment
damage, injury, and/or death.
It is the installer’s and end user’s
responsibility to read and understand
the inclusions of this, ailiated manuals,
and related documentation before
operating the associated equipment.
Failure to operate any system containing
NVE components according to OEM
specifications and proper training can
result in serious injury or death! ALWAYS
provide all users with proper training.

B250 Challenger Series | 9www.natvac.com | 800.253.5500 Weights and measurements are
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Indicates a hazardous situation which, if not avoided, will result in
death or serious injury.
Indicates a hazardous situation which can cause damage to
machine, personal property, and/or the environment, or cause the
equipment to operate improperly.
Indicates a hazardous situation which, if not avoided, could result in
minor or moderate injury.
Indicates a hazardous situation which, if not avoided, could result
in death or serious injury.

10 | B250 Challenger Series www.natvac.com | 800.253.5500
Weights and measurements are
for reference only.
Safety Precautions
It is vitally important that safety considerations be implemented
in the operation and service of this and other NVE products. While
outlining every safety precaution is beyond the scope of this manual,
some of the most important precautions include the following:
• The blower and associated drive system include rotating
components. Before any service, ensure the equipment is locked
out and that accidental startup cannot occur. Also, ensure proper
guarding is present on the components.
• This blower and associated components operate at elevated
temperatures that can cause severe burns. Be sure equipment is
cool before conducting any service or maintenance operations.
• Never operate the system without adequately sized and
functional pressure relief valves in position. This blower is
capable of producing pressures above most tank manufacturers’
specifications.
• Use suitable liing equipment to li & move the blower/blower
package. Improper liing can cause injury and/or damage to the
equipment.
• Do not expose any part of your body to vacuum. This blower is
capable of producing vacuum levels that can cause serious injury.
• Never disconnect any fiings/hoses with the blower operating.
• Ensure that appropriate Personal Protective Equipment is being
worn when operating and/or servicing the equipment.
• This system must not be used to convey explosive, toxic,
dangerous, or unstable gases/media.
• This system should only be operated and/or serviced by properly
trained individuals. NVE cannot be held responsible for damage
and/or injury caused by improper equipment use/service.
• Ensure all operating limitations are understood and followed in the
installation, operation, and maintenance of the entire system.
It is the installer’s and end user’s
responsibility to read and understand
the inclusions of this, ailiated manuals,
and related documentation before
operating the associated equipment.

B250 Challenger Series | 11www.natvac.com | 800.253.5500 Weights and measurements are
for reference only.
B250 TRI-LOBE BLOWER
NVE B250
TRI-LOBE BLOWER
General Blower Operation
NVE B250 positive displacement
blowers operate with two tri-lobe rotors
to reduce pulsation levels. These are
non-ballast ported machines, which
limits the continuous vacuum levels
that can be maintained. These blowers
operate on the principal of the opening
and closing of “pockets” that trap air
and convey it from the intake port to the
exhaust port. The opening of the lobes
creates a vacuum that pulls air into
the intake of the blower. The air is then
trapped between the rotor lobes and the
housing and conveyed to the exhaust
port where, by the lobes coming together, the air is forced out
the exhaust port. Timing gears control the positions of the two
rotors relative to each other and maintain precision clearances
inside the machine. This allows the unit to operate without
lubrication inside the pumping chamber. The airflow capacity of
the machine (in Actual Cubic Feet/Minute) is nearly proportional
to the rotational speed of the machine and is nearly indirectly
proportional to the pressure
dierential across the machine.
Location of Serial Number
Each NVE B250 blower will have a
stainless-steel blower tag bolted
to the non-drive end plate of the
blower as shown in the figure to the
right. This serial number should be
referenced in any contact with NVE
regarding the unit.
NVE B250 TRI-LOBE BLOWERS
General Blower Operation
NVE B250 positive displacement blowers operate with two tri-lobe rotors to reduce
pulsation levels. These are non-ballast ported machines, which limits the continuous vacuum
levels that can be attained. These blowers operate on the principal of the opening and closing
of “pockets” that trap air and convey from the intake port to the exhaust port. The opening
of the lobes creates a vacuum that pulls air into the intake of the blower. The air is then
trapped between the rotor lobes and the housing and conveyed to the exhaust port where, by
the lobes coming together, forces the air out the exhaust port. Timing gears control the
positions of the two rotors relative to each other and maintain precision clearances inside the
machine. This allows the unit to operate without lubrication inside the pumping chamber. The
airflow capacity of the machine (in Actual Cubic Feet/Minute) is nearly proportional to the
rotational speed of the machine and is nearly indirectly proportional to the pressure
differential across the machine.
INTAKE
EXHAUST
General Blower Construction



Location of Serial Number
Each NVE B250 blower will have a stainless-steel blower tag bolted to the non-drive
endplate of the blower as shown in the figure to the right. This serial number should be
referenced in any contact with NVE regarding the unit.

12 | B250 Challenger Series www.natvac.com | 800.253.5500
Weights and measurements are
for reference only.
SPECIFICATIONS
Operating Environment
NVE B250 blowers are designed to move atmospheric air. Do NOT
use this blower to move explosive, toxic, or corrosive gases or
operate the blower in an area with explosive gases. Contamination
in the intake air must be filtered and/or separated from the air by
means of an intake filter, moisture trap and/or a cyclonic filter. These
filtration and separating devices must be regularly maintained to
ensure proper operation of the blower. Excessive pressure drop
across these devices can cause overheating of this blower. The
blower package should be shielded from excessive sources of dust
and debris. A special emphasis should be placed on the atmospheric
outlet location of the system as this becomes the inlet of the blower
when running in pressure mode. The blower exterior should be kept
clean to promote maximum heat transfer to the surrounding air.
Operating Limits
The NVE B250 is a non-ballast ported machine. Thus, this blower
has a limited pressure dierential rating across its intake and
exhaust ports for continuous operation. The blower must always
be operated within this limit. Operation above this limit will cause
the blower to overheat and may cause catastrophic failure of
the blower. This limit is aected by several parameters. These
parameters include the following: The RPM of the machine,
ambient air temperature, inlet & outlet restrictions of the
machine, altitude of the machine, and the run time duration of the
machine.
As a general rule, higher machine input speeds, higher ambient
air temperatures, and longer operation times will result in higher
blower operation temperatures. The system should be designed
to result in a continuous blower exhaust temperature not
exceeding 370ºF or 280ºF over ambient (whichever is lower). This
measurement should be made on the exhaust side of the blower
housing.
* RPMs up to 2500 are acceptable pending exhaust temperatures are tested and
found to be within specifications shown above.
+ This should only be used as a reference. The system must be calibrated so that
the blower exhaust temperature does not exceed the rating shown in the table
above. This is dependent on many factors and may cause actual inlet vacuum to
vary from the value presented above.
Input Speed Exhaust Temperature ∆ Pressure Inlet Vacuum
1800-2400* 280ºF over ambient or 370ºF 15 PSI + ≈ 15” Hg (Corrected) +

B250 Challenger Series | 13www.natvac.com | 800.253.5500 Weights and measurements are
for reference only.
Performance (Reference Only)
Performance of your NVE B250 blower may deviate from the
aforementioned data for numerous reasons. These reasons
include things such as: ambient temperature, oil condition,
bearing condition, cleanliness of the media being pumped, etc.
Thus, the performance values presented above should only be
used for reference purposes. Actual operating conditions may
vary and it is the system designer’s responsibility to account for
these variations.
Air Flow Control
The airflow rate of the blower can be adjusted by changing the
speed of the blower. This can be accomplished by changing the
PTO ratio, the gearbox ratio, pulley ratio (on belt drives), hydraulic
pump/motor displacement, or driving engine speed. The blower
input speed is nearly proportional to the airflow of the machine.
Sound Control
It is recommended the operator monitor the blower while running
and listen for resonances (increased levels of noise) that may
occur at certain RPMs and operate the blower at speeds above or
below the resonance speeds to reduce excess noise. Resonance
areas are dependent on many factors and tend to be application
specific.
The noise level of the blower will increase with higher levels of
vacuum and RPM. To minimize noise, operate the blower at the
minimum speed and vacuum level required to achieve the desired
performance.
Vacuum (Inches of Mercury) Pressure (PSI)
RPM 0 4 8 10 12 14 15 5 10 15
HP 3.1 3.5 4.9 5.6 6.6 7.5 7.8 6.4 14.5 38.0
2000 TORQUE 8.2 9.2 12.8 14.7 17.4 19.6 20.5 16.8 26.5 38.0
CFM 228
2200
HP 3.8 4.1 5.6 6.5 7.3 8.3 8.8 8.1 12.1 16.5
TORQUE 9.1 9.8 13.3 15.4 17.6 19.9 21.1 19.3 28.9 39.5
CFM 240
2400
HP 4.6 5.4 6.2 7.1 8.1 9.0 9.5 8.5 13.2 18.1
TORQUE 10.1 11.8 13.5 15.5 17.7 19.6 20.7 18.7 28.8 39.5
CFM 262
2600
HP 5.9 6.5 7.2 8.1 9.1 10.1 10.7 10.0 14.4 20.2
TORQUE 12.0 13.1 14.6 16.4 18.4 20.5 21.6 20.2 29.1 40.9
CFM 285
B250

14 | B250 Challenger Series www.natvac.com | 800.253.5500
Weights and measurements are
for reference only.
Rotation & Airflow
Either port can be used for intake and exhaust connection to the
blower. However, the handle position for vacuum and pressure
will vary accordingly. In the “vacuum” position, the four way valve
must be positioned to connect the intake port to the intake
connection (the tank). The following graphics portray this hookup
and airflow information as it relates to the B250 blower.
INTAKE PORT
EXHAUST PORT
Rotation & Airflow
Either port can be used for intake and exhaust connection to the blower. However, the handle position
for vacuum and pressure with vary accordingly. In the “vacuum” position, the four way valve must be
positioned to connect the intake port to the intake connection (the tank). The following graphics portray
this hookup and airflow information as it relates to the B250 blower.
INTAKE PORT
EXHAUST PORT
EXHAUST PORT
INTAKE
PORT
SHOWN IN VACUUM MODE
INTAKE PORT
EXHAUST PORT
Rotation & Airflow
Either port can be used for intake and exhaust connection to the blower. However, the handle position
for vacuum and pressure with vary accordingly. In the “vacuum” position, the four way valve must be
positioned to connect the intake port to the intake connection (the tank). The following graphics portray
this hookup and airflow information as it relates to the B250 blower.
INTAKE PORT
EXHAUST PORT
EXHAUST PORT
INTAKE
PORT
SHOWN IN VACUUM MODE

B250 Challenger Series | 15www.natvac.com | 800.253.5500 Weights and measurements are
for reference only.
Handling
When unpacking the blower or blower package from the skid,
verify the packing list matches the product supplied and that no
visible damage has occurred during shipping. In the event damage
has occurred, first file a claim with the carrier and then contact
NVE for assistance.
Keep all intake and exhaust ports covered to prevent accidental
ingestion of materials into the blower.
Use an appropriately sized li strap for the weight of the blower or
package being lied.
Do NOT use li points on the blower to pick up blower packages.
The blower was not designed to be used as a pick point for
packages. Damage to the blower and/or package will likely result.
The blower stand includes liing pockets that can assist in liing
the package.
The dry weights of the B250 and associated packages are given in the
table below:
Handling
When unpacking the blower or blower package from the skid, verify the packing list matches the
product supplied and that no visible damage has occurred during shipping. In the event damage has
occurred, first file a claim with the carrier and then contact NVE for assistance.
Keep all intake and exhaust ports covered to prevent accidental ingestion of materials into the blower.
Use an appropriately sized lift strap for the weight of the blower or package being lifted.
Do NOT use lift points on the blower to pick up blower packages. The blower was not designed to be
used as a pick point for packages. Damage to the blower and/or package will likely result. The blower
stand includes lifting pockets that can assist in lifting the package
The dry weights of the B250 and associated packages are given in the table below
Part Number
Description
Dry Weight
131-B250-LSM
Blower, B250, Low Shaft, CCW, Manifold
242 LBS
147-B250-001
B250 Frame Mount Gearbox Drive, RH MT & Exhaust Silencer
Package
531 LBS
147-B250-002
B250 Frame Mount Hydraulic Drive A Face Kit, RH MT &
Exhaust Silencer Package
496 LBS
147-B250-003
B250 Frame Mount Hydraulic Drive B Face Kit, RH MT &
Exhaust Silencer Package
492 LBS
Table 1: B250 Blower & Packaging Dry Weights
PART NUMBER DESCRIPTION DRY WEIGHT
131-B250-LSM Blower, B250, Low Sha, CCW, Manifold 242 LBS
147-B250-001 B250 Frame Mount Gearbox Drive, RH MT & Exhaust Silencer Package 531 LBS
147-B250-002 B250 Frame Mount Hydraulic Drive A Face Kit, RH MT & Exhaust
Silencer Package
490 LBS
147-B250-003 B250 Frame Mount Hydraulic Drive B Face Kit, RH MT & Exhaust
Silencer Package
496 LBS
Table 1: B250 Blower & Packaging Dry Weights
Improper handling of the blower can
cause blower damage and/or dropping of
the blower. Ensure the load is balanced
before picking.

16 | B250 Challenger Series www.natvac.com | 800.253.5500
Weights and measurements are
for reference only.
Preservation
Keep all intake and exhaust port coverings in place to prevent
debris or liquids from entering blower. Reapply rust preventative
oil to all metal parts, including the pumping chamber every six
months or more frequently if the relative humidity is greater than
80%.
While in storage, rotate the sha three to four revolutions every
two weeks to keep gears coated in oil. Before installing a blower
that has been stored for any length of time, remove the intake and
exhaust covers and inspect the rotors and cylinders to insure the
absence of rust. In addition, remove the oil fill plug on the drive oil
tank and inspect the gear for any evidence of rust.
Dispose of used rust preventative oil
according to local and EPA regulations
in an environmentally friendly manner.
Use a rust preventative oil with a flash
point over 400ºF. Drain oil prior to
puing unit in service.

B250 Challenger Series | 17www.natvac.com | 800.253.5500 Weights and measurements are
for reference only.
Limitation of Use Reason for Limitation and/
or Risk Corrective Actions
Operation of the blower in an
explosive environment.
Fire and/or explosion can
result.
DO NOT USE
Using blower to move
explosive, toxic, or
dangerous gases.
Fire and/or explosion can
result.
Pollution of the environment.
Health and injury risks to
operator(s).
Liquid drawn into blower
intake.
Blower seizure, damage to
blower, and possible ejection
of parts.
Install a moisture trap or
cyclonic separator before
the intake port of the blower.
If liquid is suspect in the
blower, remove before
starting blower.
Operation above 15 in Hg* of
intake vacuum.
*Value may vary slightly
depending on application.
Overheating of blower.
Eventual catastrophic failure
of blower.
Potential Fire.
Install a properly sized
vacuum relief to keep blower
exhaust temperatures within
specifications. Keep intake
filter clean.
Operation with exhaust port
blocked o or restricted.
Overheating & potentially
dangerous system pressure.
Remove blockage and
minimize restriction in the
exhaust circuit.
Rotation of the blower in the
wrong direction. Damage to the blower.
Change the direction of
rotation of the drive.
(Jog blower to confirm
correct rotation at first
startup).
Operation of blower in
excess of recommended
speed.
Overheating & potential
seizure of blower. Blower
damage & ejection of parts
possible. Operate the blower within the
recommended speed range.
Operation of blower below
minimum speed.
Potential seizure of blower.
Blower damage & ejection of
parts possible.
Operating at excessively hot
inlet & atmospheric condi-
tions.
Overheating of blower.
Eventual catastrophic failure
of blower.
Monitor the blower operating
temperature & adjust intake
vacuum and/or RPM to get
operating temperatures
within specification. Keep
blower & intake filter clean.
Operating at excessively cold
inlet & atmospheric condi-
tions.
Damage to, and potential
seizure of, the blower.
Ejection of parts possible.
Review precautions in cold
weather conditions. Use
recommended lubrication.
Operating above the exhaust
temperature upper limit.
Overheating of blower.
Potential fire.
Damage to, and potential
seizure of, the blower.
Reduce intake vacuum level.
Reduce the blower speed.
Remove restrictions in intake
& exhaust circuits (clean inlet
filter!).
Operation of drive with
excessive misalignment.
Damage to, and potential
seizure of, the blower.
Ejection of parts possible.
Remove misalignment &
replace wearing components
in drive system.
Limitations of Use

18 | B250 Challenger Series www.natvac.com | 800.253.5500
Weights and measurements are
for reference only.
INSTALLATION CONSIDERATIONS
Any B250 blower package should be mounted to the frame of
the truck in a suicient manner. Truck manufacturers’ should be
consulted for proper mounting. NVE cannot take responsibility for
the mounting of any NVE product.
The exhaust discharge of the blower silencer should be
considered in the installation of the package. Remember, this
becomes the intake when the blower is operated in pressure
mode, so ensure hot and/or dirty air is not going to be pulled into
the silencer.
The moisture trap, if equipped, should be plumbed to the primary
shuto and, ultimately, the tank. The connection must be vacuum,
pressure, and temperature rated.
Ensure proper ground clearance is maintained with installation
location.
Inlet connection to primary
shuto (tank)
Exhaust to atmosphere in
vacuum mode & inlet in
pressure mode
Fill out the blower registration form and it email to [email protected].
Fill out the installation check list & warranty validation form and email
it to [email protected].
Never block or restrict exhaust discharge.
Dangerous style pressures are possible.

B250 Challenger Series | 19www.natvac.com | 800.253.5500 Weights and measurements are
for reference only.
Belts and pulleys must be fully guarded
to prevent entanglement and ejection
of parts.
Belt Drive System
The B250 blower is able to accommodate a V-Belt drive system.
It is recommended to mount the prime mover on the intake side
of the blower. This prevents unloading of the blower bearings
at low load levels and also helps reduce the moment load on
the bearings. The pulley should be mounted as close to the oil
sump cover of the blower as possible (with a minimum ¼” gap).
Some method of belt tension adjustment must be installed to
take up belt wear. Belts should be matched to insure uniform
torque transmission. Belts should be replaced in sets. Due to
the inherently higher hub loads generated, synchronous drive
systems should not be used on a B250 blower.
Excessive or insuicient belt tension could damage the blower and/
or prime mover.
Regularly check all bushing fasteners for proper torque, especially
aer initial run in or aer any belt drive service.
A belted drive specialist should be consulted for design review of a
belted drive system incorporating NVE components.

20 | B250 Challenger Series www.natvac.com | 800.253.5500
Weights and measurements are
for reference only.
Drive Sha System
U-Joint operating angles at each end of the sha should always
be to manufacturers’ specifications to prevent yoke bearing
failure. Do not exceed the manufacturers maximum or minimum
recommended angles for the operating RPM.
U-Joint operating angles on each end of a drive sha should
always be equal within manufacturers’ specification of each other
to cancel any angle vibration. A drive line specialist should be
consulted for the design of this system from a torque transfer
and geometric approach. The drive sha should be balanced to
manufacturers’ specification.
Diesel Engine Precautions
This blower should not be operated with a diesel engine running at
low RPMs. Diesel engines at low RPMs are capable of producing
damaging torque pulses that can cause rotor lobe contact and/or
accelerated wear of bearings and gear components.
A drive sha loop should be used to catch
the sha in the event of failure and to
prevent the ejection of parts.
Drive shas represent rotating parts and
pose entanglement hazards.
NEVER approach a rotating system.
It is recommended that overload
protection be incorporated on the
driveline.