M.K.Plastics PRVS User manual

M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 1 of 12
Bulletin 25-02-February 2017
PRVS
Centrifugal Fiberglass Blower
INSTALLATION, OPERATIONAND MAINTENANCE MANUAL
Introduction
This bulletin contains the proper installation, operation and
maintenance procedures for the standard PRVS High
Pressure/Low Volume Centrifugal Fiberglass Blower to
ensure safe and trouble-free blower operation. This bulletin
complements good general practices; however it is the
responsibility of the purchaser to provide qualified
personnel experienced in the installation, operation and
maintenance of air moving equipment.
The M.K. Plastics catalog on the PRVS blower provides
additional information describing the equipment, blower
performance, available accessories and specifications. It is
available via our website at www.mkplastics.com.
For additional safety information, refer to AMCA publication
410: Recommended Safety Practices for Users and
Installers of Industrial and Commercial Fans.
For information on special blower application requirements,
please contact the M.K. Plastics corporate office at
[phone], US Toll Free: 1-888-278-9988 or via our
website at www.mkplastics.com.
Figure 1
PRVS Centrifugal Fiberglass Blower
WARNING
This unit has rotating parts. Safety precautions should
be exercised at all times during installation,
operation, and maintenance.
ALWAYS disconnect power prior to working on blower.
Electrical Disconnects
Every motor-driven blower or fan should have an
independent disconnect switch to isolate the unit from the
electrical supply. The disconnect switch should be near the
blower and must be capable of being locked by
maintenance personnel while servicing the unit.
Maintenance personnel must be provided complete control
of the power source.
Moving Parts
All moving parts must have guards to protect personnel. All
PRVS blowers are supplied with vented FRP belt and shaft
guards. Never start a blower without having all safety
guards installed. Check regularly for damaged or missing
guards and do not operate any blower with guards
removed.
Sound
Blowers can generate sound that could be hazardous to
exposed personnel. Appropriate ear protection should be
used by maintenance personnel.
Air Pressure and Suction
Blowers present a hazard from the suction created at the
blower inlet. This suction can draw materials into the
blower where they become high velocity projectiles at the
outlet.Inlets and outlets that are not ducted should be
screened to prevent entry and discharge of solid objects.
PRVS blowers can be supplied with inlet and/or outlet PVC
or stainless steel screens.
View Ports
View Ports to the duct system should never be opened
while the blower is in operation. Serious injury could result
from the effects of air pressure or suction.
Receiving and Inspection
All M.K. Plastics blowers and fans are carefully inspected
before leaving the factory. Compare all components with
the bill of lading or packing list to verify that the proper unit
was received. Check each unit for any damage that may
have occurred in transit:
•Turn the wheel by hand to ensure it turns freely
and does not bind.
•Inspect the dampers (if supplied) for free operation
of all moving parts.
•Record on the Delivery Receipt any visible sign of
damage.
Mishandled units can void the warranty provisions. If units
are damaged in transit, it is the responsibility of the receiver
to make all claims against the carrier. M.K. Plastics will
assist the customer as much as possible; however claims
must be originated at the point of delivery. M.K. Plastics is
not responsible for damages incurred during shipment.

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 2 of 12
Handling
PRVS Blowers are to be hoisted and moved by the base or
by lifting lugs provided on the blower. See Figure 2. The
location of lifting lugs varies by blower size and
arrangement.
Fans and blowers should never be lifted by the shaft,
blower housing, motor, belt guard, damper, weather hood,
inlet & outlet flanges or any other accessories.
Figure 2
Lifting Lug Locations
Storage
If the unit cannot be installed and operated immediately,
precautions need to be taken to prevent deterioration of the
unit during storage.Blowers and fans are frequently
received on site well before they are put into operation.
Proper storage techniques drastically reduce the likelihood
of the blower not operating successfully. The user assumes
responsibility of the blower and accessories while in storage.
M.K. Plastics will not be responsible for damage during
storage.
Whenever possible store the blower and accessories in a
clean, dry and protected area. Ensure that the blower
shaft, bearings and impeller are protected against dust
and corrosion. Cover and seal bearings to prevent
entrance of contaminants. Cover the inlet and outlet to
prevent the accumulation of dirt and moisture in the
housing. Cover motors with waterproof material.
If it is necessary to store outdoors or within a building under
construction, special care must be taken to prevent
moisture, dirt or dust accumulation. Cover completely with
a tarp or heavy plastic wrap.
At least once a month, the impeller should be rotated about
ten revolutions to circulate the grease in the bearings. Stop
the shaft in a different location than where it was previously
stopped.
Block impeller to prevent natural rotation. Do not allow
material of any kind to be piled on top or inside of the
blower. Electrical connections and leads must be protected
from moisture. Reduce the belt tension on belt driven
blowers. This reduces the load on the bearings, minimizing
the potential for problems. Do not store the blower in a
location where it will be subjected to vibration.
Pre-Installation
When the unit is removed from storage after a long
duration, the motor should be measured to verify that the
resistance is still at a satisfactory level compared to the
value recorded prior to storage.
Inlet & Outlet Blower Aerodynamic
Installation
Efficient blower performance relies on the proper
installation of inlet and discharge ducts. Installations with
poor inlet or discharge configurations may result in reduced
performance. Restricted or unstable flow at the blower inlet
can cause pre-rotation of incoming air or uneven loading of
the blower wheel resulting in increased system losses and
sound levels. Free discharge or turbulent flow in the
discharge ductwork will also result in system losses. Note
the following recommendations:
Inlet Duct Turns:
Installation of a duct turn or elbow too close to the blower
inlet reduces blower performance. To achieve full blower
performance, there should be at least three inlet diameters
between duct turns or elbows and the blower inlet. Abrupt
turning without rounded corners should be avoided.
Turning vanes should be installed when possible to
maintain full blower performance. See Figures 3 and 4.
Figure 3
Poor Inlet Duct Installation
Figure 4
Good Inlet Duct Installation

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 3 of 12
Inlet Spin:
A common cause of reduced blower performance is inlet
spin. To prevent this occurring, it is good practice to use
turning vanes in the duct to reduce the effects. See Figures
5 and 6.
Figure 5
Good Prevention of Inlet Spin
Figure 6
Poor Prevention of Inlet Spin
Discharge Duct Turns:
Where possible, allow a minimum of three outlet diameters
between the fan outlet and any turns or elbows. Fan
performance is reduced when turns are made immediately
off the fan discharge. See Figure 7.
The location of the PRVS blower outlet can be catered to
the specific installation. Fourteen positions are available for
PRVS blowers. Where possible, use a different blower
position to reduce the amount of turns or elbows.
Figure 7
Poor vs. Good Outlet Duct Installation
Free Discharge:
Avoid a free discharge into a plenum. This will result in lost
efficiency because it will cause turbulence and does not
allow for static pressure regain. See Figure 8.
Figure 8
Free Discharge to be avoided
Inlet & Outlet Blower Structural
Installation
Blower Installation:
Follow proper handling instructions given on previous page,
paying attention to using the lifting lugs instead of any other
part of the blower to hoist or move the blower.
•Move the blower to the final mounting position.
•Remove skid, crates and packing materials
carefully.
•If supplied, place vibration pads or isolation base
on mounting bolts. Line up holes in the blower
base with bolts.
•Place blower on mounting structure. Carefully
level utilizing shims as required at all mounting-
hole locations. Bolt down the unit.
•Any grout may now be used. Bolt the blower in
position before applying grout. Do not depend
upon grout to support rotating equipment.
•Continue with the Operational Checklist, at the
end of this document.
Additional instructions may be given for some blower sizes,
components and accessories in the M.K. Plastics Submittal.
Support Structure:
Essential to every PRVS blower installation is a strong,
level foundation under the blower, or rigid support structure
to which it is suspended. The foundation or support
structure size is determined by the blower arrangement,
size, weight, motor weight, position (blower orientation) and
location of the installation. Roof or floor structure supports

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 4 of 12
should be per the structural engineer in accordance with
load requirements and applicable building codes.
Vibration Isolators:
To prevent vibration and noise from being transferred
to the building, vibration isolators are recommended.
Isolators should be located between the blower system and
the support structure. M.K. Plastics supplies four main
types of isolators for PRVS blowers. All are corrosion and
weather resistant using galvanized steel housings and
epoxy-coated steel springs.
•Floor Mounted Seismically Restrained Spring
Isolators (1” to 4” deflection.) See Figure 9.
•Floor Mounted Non-Restrained Housed Spring
Isolators (1” to 3” deflection.) See Figure 10.
•Floor Mounted Rubber-In-Shear Isolators (rubber
mounts, up to .5” deflection.) Metal parts are
embedded in elastomer for corrosion and weather
resistance. See Figure 11.
•Hanging Spring Isolators. See Figure 12.
Refer to the M.K. Plastics Submittal for isolator
installation and adjustment instructions.
Figure 9
Seismically Restrained Spring Isolators
Figure 10
Non-Restrained Housed Spring Isolators
Figure 11
Floor Mounted Rubber-In-Shear Isolators
Figure 12
Hanging Spring Isolators
After the blower and isolators are installed the entire
assembly must be leveled. Position the level on the blower
base, not the blower shaft for proper leveling. Additionally,
the motor and blower shafts must be level and parallel
relative to each other for proper alignment. Installation
instructions are found on the Vibration Isolator drawings
which are supplied with each PRVS blower Submittal.
Inlet & Outlet:
To prevent vibration and noise from being transferred
to the ducting, flexible connectors are recommended.
Ductwork which is rigidly connected will transmit vibration
directly through the ductwork. This can cause structural
damage to the blower components and the support
structure. M.K. Plastics supplies vinyl compound FPVC
flexible connectors upon request. They can be used for the
inlet, outlet or both. Stainless steel draw bands are
supplied for attachment to the inlet sleeve, and an
additional flange and sleeve can be provided for the outlet
upon request.
When installing the flex connectors, ensure that the
connector is not over compressed, such that it can be
drawn into the airstream, block or distort the flow into or out
of the blower. See figure 13.

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 5 of 12
Figure 13
Flex Connector Installation
Care must be taken when using a blower to support
ductwork. PRVS blowers are not designed to carry high
external loads. Adding such loads to the blower may cause
the impeller to rub or cause other misalignments which
could damage the blower. Check with M.K. Plastics before
mounting ductwork onto the blower to ensure the blower
design can handle the loads. PRVS blowers are supplied
with extra front support to accommodate specific
installations such as Stack Extensions.
The PRVS outlet flange is supplied undrilled. Drilling can
be done by M.K. Plastics upon request, or done by the user.
A hole-pattern can be found on the PRVS Data Sheet
supplied with the blower. This hole-pattern will ensure the
structural integrity of the FRP flange. An inlet flange can be
supplied when required, pre-drilled or undrilled.
When installing a flanged component to the PRVS outlet or
inlet flange, a gasket is recommended. M.K. Plastics uses
a single-sided, neoprene sponge tape, 1/8” x 1”. This
avoids any leakage or any air being entrained into the
exhaust.
Care must be taken to avoid over-torqueing the bolts
attaching the PRVS outlet or inlet flange. The FRP flange
may crack if too much torque is applied to these bolts. A
guideline is to crush the neoprene seal without collapsing it
entirely.
Wheel-Inlet Clearance
The correct wheel (impeller)-inlet clearance is critical to
proper blower performance. This clearance should be
verified before initial start-up since rough handling during
shipment could cause a shift in blower components. It
should be re-checked after the blower has been in
operation for 24 hours. For all PRVS blower sizes this
clearance is 1/8” (0.125”). See Figure 14. The clearance
is adjusted by loosening the wheel hub on the shaft and
moving the wheel to the correct position. A trim balance
maybe required.
Figure 14
Wheel-Inlet Clearance
Drive Installation and Maintenance
Drive Alignment:
Belt drives are aligned in the factory, but may no longer be
aligned when the blower arrives at the job site. Parts can
move out of alignment during shipping and handling.
For belt driven blowers, proper belt alignment is critical for
long belt life. Misaligned sheaves cause uneven belt wear
and additional flexing of the belt, both of which reduce the
life of the belt. Figure 15 shows properly aligned sheaves,
as well as sheaves with offset misalignment and sheaves
with two types of angular misalignment. Use a straightedge
to assess the alignment of the sheaves. Ensure that the
straightedge contacts the entire face of both sheaves.
Figure 15
Drive Misalignment
Pulley alignment is adjusted by loosening the motor sheave
setscrew and by moving the motor sheave on the motor
shaft, or by moving the entire motor along the motor
mounting bracket.
A recommended method of inspecting the pulley alignment
is shown in Figure 16. With the shorter leg of a carpenter’s
square or other straight edge lying along the case of the
motor, adjust the position of the motor sheave (or the motor)
until the longer leg of the square is parallel to the belt.

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 6 of 12
Figure 16
Method of Inspecting Pulley Alignment
Belt Tension:
Proper belt tension is important for long belt life and
optimum efficiency. Too much tension puts excessive loads
on the belts and the bearings which reduces the lives of
both components. Not enough tension allows belt slippage
which generates heat and drastically reduces the life of the
belt. The proper tension for operating a V-belt is the lowest
tension at which the belts will not slip at peak load
conditions.
All M.K. Plastics blowers and fans are shipped with the
proper belt tension. This tension is calculated for each
specific blower delivery, and is measured at the factory with
a belt tensioning gauge, as shown in Figure 17.
Figure 17
Belt Tensioning Gauge
When replacing the belt, if a belt tensioning gauge in not
available, the belt tension may be determined roughly by
the belt deflection half-way between pulley centers. The
deflection at the center should be roughly 1/50” for each inch
of belt span, or approximately 1/4” per foot of belt span. See
Figure 18.
Figure 18
Belt & Pulley Tension
Belt tension may also be determined by the sound the belts
make when the blower is first started. Belts will produce a
loud squeal which dissipates after the blower is operating at
full capacity. Re-tension the belts just tight enough so that
the squeal when starting the blower dissipates quickly. A
short “chirp” is acceptable; a squeal lasting several seconds
or longer is not.
New belts may stretch a little at first, so re-check belt
tension after 8 hours, 24 hours and 30 days of operation.
Do not change the sheave pitch diameter to change
tension. This will result in a different blower speed than
desired. Adjusting belt tension is easily done by raising or
lowering the motor support plate. Never use belt dressing
on any belts.
V-belt drives need periodic inspection, re-tensioning, and
occasional sheave and/or belt replacement. Dirt build-up,
burrs or obstructions can cause premature belt or drive
replacement. If burrs are found, use a fine emery cloth or a
stone to remove them. Be careful that dust does not enter
the bearings. Check sheaves for wear. Excessive slippage
of belts on sheaves can cause wear and vibration. Replace
worn sheaves with new ones. Carefully align sheaves to
avoid premature sheave failure (see previous section on
Drive Alignment.)
Recommended procedure for belt tensioning:
1. Loosen motor plate adjustment bolts and move
motor plate in order that the belts can easily slip
into the grooves on the sheaves. Never pry, roll,
or force the belts over the rim of the sheave.
2. Adjust the motor plate until proper tension is
reached.
3. Lock the motor plate adjustment nuts in place.
4. Recheck the alignment and realign the sheaves if
necessary.
Recommended procedure for sheave & belt
replacement:
1. Remove sheaves from their shafts.
2. Clean the motor and blower shafts.
3. Clean bores of sheaves and coat the bores with
heavy oil.
4. Remove grease, rust or burns from the sheaves
and shafts.
5. Remove burrs from the shaft by sanding.
6. Place blower sheave on the blower shaft and
motor sheave on its shaft. Damage to the sheaves
can occur when excessive force is used in placing
the sheaves on their respective shafts.
7. Tighten in place.
8. Install belts on sheaves and ensure proper
alignment and tension.
Motor Maintenance
Motor maintenance is per the Motor manufacturer’s
instructions which are supplied with the motor. However
the following guidelines may be used:
1. Keep the motor clean.
2. Keep the motor dry.
3. Keep the motor properly lubricated.
Blow dust off periodically with low pressure air to prevent
the motor from overheating.
On PRVS blowers, motor bearings are pre-lubricated and
sealed. Under normal conditions they will not require
further maintenance for extended periods. Use the motor
manufacturer’s recommendations for re-lubrication and
servicing.

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 7 of 12
PRVS blowers that are Direct Drive Arrangement 4 are
supplied with a motor shaft that is drilled and tapped to
accommodate the blower shaft. Contact M.K. Plastics if a
motor replacement is ever necessary.
Should the motor prove defective within a one-year period,
contact M.K. Plastics directly, or you may contact your
nearest motor service representative.
Wheel and Shaft Maintenance
Periodically inspect the shaft and wheel for dirt buildup,
corrosion, and signs of excess stress or fatigue. The wheel
can be inspected via the view port. Clean the components
as necessary. If the wheel is removed for any reason,
make sure that it is securely attached to the shaft before
restarting the blower.
Drainage Detail
All PRVS blowers come with outlet drains due to water or
condensation that may accumulate. Proper disposal of the
water is necessary. Connect the drain outlet to a drainage
system (by others.)
Blower Bearings
All PRVS blowers are equipped with solid pillow block
bearings. They are equipped with an integral set screw
lock.
Blower Bearing Lubrication:
All PRVS Blowers use only Self-Lube pillow block bearings.
Bearings are factory charged with the correct amount of
grease and do not require further grease charge.
Re-lubrication is not required. See Figure 19.
Figure 19
Solid Pillow Block Bearing
Note: The motor bearing lubrication should be per the
motor manufacturer’s instructions.
Blower Bearing Replacement:
Blower bearing replacement intervals are defined by the
blower operator. M.K. Plastics does not define a schedule
for bearing replacement, as it is dependent on the
environment, usage and maintenance of each specific
blower installation. With proper installation, operation and
maintenance however, PRVS bearings should last several
years. All PRVS blowers are equipped with NSK, RHP
Self-Lube cast iron pillow block units, NP or MP series.
Indicators that bearings need replacement include
excessive noise, vibration or heat in the vicinity of the
bearings.
In applications where contact with the exhaust poses a
serious contamination factor, the bearings can be removed
without removing the wheel and inlet cone. In this case, the
shaft must be held in place with suitable straps or bracings
firmly secured around the bearing support frame. The shaft
must be supported to restrict any lateral movement of both
the shaft and impeller.
Removal of Wheel, Shaft & Bearings:
1. Take note or make a sketch of the position on the
shaft of both bearing races, setscrews and the
wheel and sheave. If you are replacing the shaft
as well, these notes or sketch will give you
reference.
2. Mark the location and orientation of the inlet to
the casing and remove. Note the clearance
between the wheel and the inlet cone. This will
give you access to the wheel.
3. Remove the drive sheave from the shaft.
4. Start wheel removal by unscrewing the front
protective cap and then the nut, washers and
threaded stud assembly that holds the cap to the
blower shaft. Unscrew the setscrews in the wheel
hub. The wheel can now be removed from the
blower shaft. PRVS blowers do not have
bushings, the wheel is held in place on the shaft
with the threaded rod assembly, 2 setscrews on
the wheel hub and key.
5. Remove the bearing housing mounting bolts and
remove the shaft and bearings as one unit. Keep
any existing shims in place.
6. The bearings are attached with set screws;
unscrew and slide the assembly off as one piece.
Tap on the bearing with a wood block and hammer
to remove if necessary.
7. If the existing shaft is being used, check the
shaft for nicks, burrs and damage. Remove any
anti-corrosion coating with a suitable degreaser
and wipe clean.
Bearing Replacement:
1. Making sure that the setscrews are not protruding
from the inner bearing rings, slide the bearings
directly onto the shaft. If using an old shaft, make
sure the bearings are not mounted on a worn
section. Tapping the inner ring face with a soft
driver might be required. Do not hammer on the
housing.
2. The outer ring of the bearing is spherical and
swivels in the housing to compensate for
misalignment. Secure the housing to the stand
with the fixing bolts, but do not fully tighten.
3. Install the wheel on the shaft, and block it in place.
Install the inlet in its original location. Position the
wheel correctly by moving the shaft axially in the
bearing assemblies.
4. Tighten the setscrews on the bearings to
secure the shaft. Refer to torque chart in Figure
20.
5. Rotate the shaft by hand to allow the bearing outer
rings to find their center of free movement.

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 8 of 12
Test Run:
1. Re-install the sheave and adjust the belt tension.
2. Retighten all setscrews and mounting bolts using
torque from Figure 20.
3. Test run and trim balance as necessary.
Pillow
Block
Bearing
Set
Screw
Torque
(in-lbs.)
Mounting Bolt 304 SS
Bolt
Torque
(in-lbs.)
316 SS
Bolt
Torque
(in-lbs.)
RHP
MP17/16 110 1/2-13UNC, 2.25L 517 542
Figure 20
Bearing Setscrew & Mounting Bolt Torque
Changing Blower Shaft Speed
All belt driven blowers with motors up to and including
5 HP are equipped with variable pitch motor sheaves. The
motor sheave diameter is variable by varying the width of
the sheave. To change the blower speed, perform the
following:
1. Loosen setscrew on driver (motor) sheave and
remove key, if equipped.
2. If the sheave has multiple grooves, all must be
adjusted to the same width.
3. After adjustment, inspect for proper belt tension.
4. To reduce speed, open the sheave in order that
the belt rides deeper in the groove (smaller pitch
diameter.)
5. To increase speed, close the sheave so that the
belt rides higher in the groove (larger pitch
diameter.) Make sure the maximum blower RPM
and maximum motor HP is not reached. The
maximum motor HP can be found on the motor
nameplate.
Grounding Straps
If the blower is supplied with a graphite liner, a grounding
strap is provided on the bottom of the scroll housing for the
removal of static electricity. This strap must be connected
to the building electrical grounding circuit or the roof steel
structure. If an Aegis shaft grounding ring is supplied on
the motor, the motor support stand should also be
grounded. See Figure 21.
Figure 21
Grounding Strap location
Operational Checklist
Final Installation
Inspect fasteners and setscrews, particularly blower
mounting and bearing fasteners, and tighten according
to the recommended torque shown in Figure 20.
Inspect for correct voltage with voltmeter.
Ensure all accessories are installed.
Pre-Start Checks
Shut off all primary and secondary power sources.
Ensure fasteners and setscrews are tightened.
Inspect belt tension and sheave alignment.
Inspect motor wiring.
Ensure belt touches only the sheaves.
Ensure blower and ductwork are clean and free of
debris.
Inspect wheel-to-inlet clearance.
Close and secure view port.
Restore power to the blower.
Start Up
Turn the blower on. In variable speed units, set the
blower to its lowest speed and inspect for the following:
Direction of rotation. (See direction arrow on back of
casing.)
Excessive vibration.
Unusual noise.
Bearing noise.
Improper belt alignment or tension (listen for
squealing).
Improper motor amperage or voltage.

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 9 of 12
If a problem is discovered, immediately shut the blower off.
Lock out all electrical power and check for the cause of the
trouble. See Troubleshooting at the end of this document.
Inspection
Inspection of the blower should be conducted at the first 30
minute, 8 hour, 24 hour and 30 day intervals of operation.
During the inspections, stop the blower and inspect:
30 Minute Interval: Inspect bolts, setscrews, and
motor mounting bolts. Adjust and tighten as necessary.
8 Hour Interval: Inspect belt alignment and tension.
Adjust and tighten as necessary.
24 Hour Interval: Inspect belt tension. Adjust and
tighten as necessary.
30 Day Interval: Inspect belt tension. Adjust and
tighten as necessary.
General Blower Maintenance
WARNING
Disconnect and secure to the ‘Off’ position all electrical
power to the blower prior to inspection and servicing.
Failure to comply with this safety precaution could
result in serious injury or death.
Once the unit has been put into operation, a routine
maintenance schedule should be established for
inspecting all parts of the blower. The frequency of
inspection depends on the operating conditions and the
location of the blower.
Regular inspections are recommended for blowers
exhausting non-contaminated air. The following inspection
is recommended twice per year:
•Inspect blower impeller and housing for fatigue,
corrosion or wear.
•Inspect bolts and setscrews on wheel, housing and
bearings for tightness. Tighten as necessary.
Worn setscrews should be replaced immediately.
•Inspect belt wear, tension, alignment and dirt
accumulation. Replace worn belts with new belts
and adjust alignment as needed. If belts have
been replaced, new belts will stretch. Belt tension
needs to be checked and adjusted after 8 hours,
24 hours, and again after 30 days of operation.
Refer to Belt Tensioning section in this
document.
•Inspect springs and rubber isolators for
deterioration or breaks and replace as needed.
•Inspect for cleanliness. Clean exterior surfaces
only. Remove dirt from the wheel and housing to
prevent imbalance and damage.
•Blow dust off the motor with low pressure air to
prevent motor from overheating. Remove grease
on motor housing. See Motor Maintenance
section in this document for details.
Inspect blowers exhausting corrosive or contaminated air
(containing airborne particles) within the first month of
operation. Blowers exhausting contaminated air should be
inspected every three months or sooner.

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 10 of 12
Troubleshooting
Excessive Noise or Vibration
•Damaged wheel.
•Wheel rubbing inlet; adjust wheel or inlet.
•Verify wheel balance, rebalance if necessary.
•Belts too loose; worn or oily belts.
•Loose fasteners.
•Speed too high.
•Incorrect direction of rotation. Verify that the blower rotates in same direction as the arrows on the motor or
belt drive assembly.
•Bearing collars or hardware loose.
•Bearings need replacement.
•Debris in impeller: clean all dirt off wheel, check wheel balance and rebalance if necessary.
•Blower surge, check for any restrictions to flow into the blower.
•Check alignment of shaft and motor drives.
Low Volume or Pressure
•Incorrect direction of rotation. Verify that the blower rotates in same direction as the arrows on the motor or
belt drive assembly.
•Poor blower inlet or outlet conditions. There should be a straight clear duct at the inlet or outlet. See Inlet &
Outlet Blower Aerodynamic Installation section above.
•Improper wheel alignment.
Motor Problems (Overheating)
•Motor improperly wired.
•Incorrect direction of rotation. Verify that the blower rotates in same direction as the arrows on the motor or
belt drive assembly.
•High horsepower: resize the ductwork. Check proper operation of any dampers. Check filters and view
port.
•Cooling air diverted or blocked.
•Improper inlet clearance.
•Incorrect blower speed.
•Incorrect voltage.
Bearing Problems (Overheating)
•Bearings reaching maximum life, replace bearings.
•Excessive belt tension
•Check for bent shaft.
•Align bearings.

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 11 of 12
Figure 22
PRVS Belt Drive Arrangement #10 Parts List
Figure 23
PRVS Direct Drive Arrangement #4 Parts List

INSTALLATION, OPERATION & MAINTENANCE MANUAL PRVS Centrifugal Fiberglass Blower Bulletin 25-02-February 2017
M.K. Plastics Corp. Montréal, Québec, Canada [phone] www.mkplastics.com Page 12 of 12
Warranty
M.K. Plastics will not be responsible for damage to equipment or materials through improper installation, storage, improper
servicing, or through attempts to operate it in excess of its rated capacity or recommended use, intentional or otherwise. We will
not be responsible for consequential damage.
Based on the fact that M.K. Plastics has no direct control over the actual handling and use of its products in the field,
M.K. Plastics does not assume any liability for any loss to the customer or any personnel or any physical damages that are
claimed by anyone due to a failure or cause attributed to the use of its products. In no event shall M.K. Plastics be responsible
for consequential damages of any such defective material or workmanship, including but not limited to the buyer’s loss of material
or profit, increase expense of operation, downtime or reconstruction of the work and in no event shall M.K. Plastics obligation
under this warranty exceed the original contract price of the defective item.
M.K. Plastics warrants its equipment, products and parts, to be free from defects in workmanship and material under normal use
and service for one (1) year after delivery to the first user. Our obligation under this warranty being limited to repairing or
replacing, at our option, without cost at our factory any part, or parts which shall, within such warranty period, be returned to us
with transportation charges prepaid, and which our examination shall disclose to our satisfaction to have been defective.
M.K. Plastics will not be responsible for the cost of removal of a defective product or parts or the installation of a replaced product or
parts, or for costs due for its removal, crating or shipping.
On account of variables including but not limited to, vibration, system noise characteristics, motor overloading or change in
voltage condition, the specifics of customer application of equipment or other system conditions, M.K. Plastics does not expressly
warrant its equipment for any specific purpose.
The customer and its agents are responsible for the selection and application of M.K. Plastics products, including their fitness for
the purpose and performance intended. Consequently, the customer on behalf of its agents assumes all liability related to the
use/misuse, application and selection of the M.K. Plastics Products.
Bulletin 25-02-February 2017
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Email: [email protected]