Roots UNIVERSAL RAI® blowers are internally and
externally treated after factory assembly to protect against
normal atmospheric corrosion before installation. Maximum
period of internal protection is considered to be one year under
average conditions, if closing plugs or seals are not removed.
Protection against chemical or salt water atmosphere is not
provided. Avoid opening the blower until ready to start
installation. as protection will be lost quickly by evaporation.
NOTE-If there is to be an extended period between
delivery (and/or installation) and startup, the following
steps should be taken to insure corrosion protection:
Coat internals of cylinder and gearbox with Nox-Rust No.
VCI10 or equivalent. Repeat once a year or as conditions
may require. Motorstor is oil soluble and does not have to
be removed before lubricating. If desired, No. VCI10 may
be removed from within the cylinder shortly before startup
by spraying a fine mist of petroleum solvent through the
blower while it is running at a slow speed with open inlet
and discharge, or it can remain in the blower if it is not
harmful to the operation of the connected system.
Fill drive end bearing cavities with grease as specified in
Paint shaft extension, inlet and discharge flanges, and all
other exposed surfaces with Nox-Rust X-110 or
Seal inlet, discharge, and all vent openings with tape. It is
not recommended that the unit be set in place. piped to
the system, and allowed to remain idle for extended
periods. If any part is left open to the atmosphere, the
Motorstor vapor will escape and lose its effectiveness.
Units are not to be subjected to excessive vibration during
storage. If stored outdoors, provide coverage such as a
tarpaulin or lean-to.
Rotate drive shaft three or four revolutions every two
Prior to startup, remove flange covers on both inlet and
discharge and inspect internals to insure absence of rust.
Check all internal clearances. Also. at this time. remove
gearbox and inspect gear teeth for rust.
Because of the completely enclosed blower design,
location of the installation is generally not a critical matter. A
clean, dry and protected indoor location is to be preferred.
However. an outdoor or wet location will normally give
satisfactory service. Important requirements are that the
correct grade of lubricating oil be provided for expected
temperatures, and that the blower be located so that routine
checking and servicing can be handled conveniently after
installation. Effect of the location on driver and accessory
equipment must also be considered.
Supervision of the installation by a Factory Service
Engineer is not usually required for these blowers. Workmen
with experience in installing light-medium weight machinery
should be able to produce satisfactory results. Handling of the
equipment needs to be accomplished with care, and in
compliance with safe practices. Blower mounting must be
solid, without strain or twist, and air piping must be clean.
accurately aligned and properly connected.
A bare blower without base should be lifted by a rope
sling, with one loop passing under the gearhouse and the
other loop under the cylinder.
When a blower is furnished mounted on a baseplate. with
or without a driver, use of lifting slings passing under the base
flanges is required. Arrange these slings so that no strains are
placed on the blower casing or mounting feet, or on any
mounted accessory equipment.
Before starting the installation, remove plugs, covers or seals
from blower inlet and discharge connections and inspect the
interior completely for dirt or foreign material. If cleaning is
required, finish by washing the cylinder, headplates and
impeller thoroughly with a petroleum solvent such as DuPont
Triclene D. After this, turn the drive shaft by hand to make
sure that the impellers turn freely at all points. Anti-rust
compound on the drive shaft extension may also be removed
at this time with the same solvent. Then plug the inlet and
discharge connections to keep out dirt until ready to connect
the air piping. Washing out is not required if the interior is
found to be clean. The corrosion inhibitor used will vaporize
and disappear during operation.
Care, plus consideration of all possible problems, will pay
dividends when arranging the blower mounting. This is
especially true when the blower is a "bare" unit furnished
without a baseplate. The convenient procedure may be to
mount such a unit directly on a floor or small concrete pad.
but this generally produces least satisfactory results. It
definitely causes the most problems in leveling and alignment.
Direct use of structural framing members is also not a
recommended mounting. If unavoidable, the members must
be rigidly reinforced when part of a building, and spring type
mountings should not be used. Noise transmission can
usually be reduced by use of a cork insulating pad 1 to 2
inches (25 to 50 mm) thickness. The pad should be supported
by a full steel plate attached to the structure, with a rigid
concrete slab laid on top of the cork to carry the blower and
For a blower without base, it is recommended that a well
anchored and carefully leveled steel or cast iron mounting
plate be provided at the installation point. The plate should be
3, 4 to 1¼, inches 119 to 32 mm) thick, with its top surface
machined flat, and needs to be large enough to provide
leveling areas at one side and one end after the blower is
mounted. It should have properly sized studs or tapped holes
located to match the blower foot drilling. As an alternative,
smaller plates at each end of the blower may be used. This is
more complicated. usually makes leveling more difficult, and
can produce twist or strains in the blower. Use of a high
quality machinist's level is important. With the mounting plate
in place and leveled, set the blower on it without bolting and
check for rocking. If it is not solid, determine the total
thickness of shims required under one foot to stop the rocking.
Place half of this under each of the two short feet, and tighten
the mounting studs or screws. Rotate the drive shaft to make
sure the impellers still turn freely. If the blower is to