Howden Roots Tri-RAM 409, Installation, Operation & Maintenance Manual

GEA19684  ISRB_2008 rev._11.15

4

Installation 

Roots blowers & exhausters are treated after factory assembly 
to protect against normal atmospheric corrosion. The maxi-
mum period of internal protection is considered to be one year 
under average conditions, if shipping plugs & seals are not 
removed. Protection against chemical or salt water atmosphere 
is not provided. Avoid opening the unit until ready to start 
installation, as corrosion protection will be quickly lost due to 
evaporation.

If there is to be an extended period between installation and 
start up, the following steps should be taken to ensure corro-
sion protection.

• 

Coat internals of cylinder, gearbox and drive end 
bearing reservoir with Nox-Rust VCI-10 or equivalent. 
Repeat once a year or as conditions may require. Nox-
Rust VCI-10 is petroleum soluble and does not have to 
be removed before lubricating. It may be obtained from 
Daubert Chemical Co., 2000 Spring Rd., Oak Brook, Ill. 
60521.

• 

Paint shaft extension, inlet and discharge flanges, and 
all other exposed surfaces with Nox-Rust X-110 or 
equivalent.

• 

Seal inlet, discharge, and vent openings. 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 
Nox-Rust VCI-10 vapor will escape and lose its effec-
tiveness.

• 

Protect units from excessive vibration during storage.

• 

Rotate shaft three or four revolutions every two weeks.

• 

Prior to start up, remove flange covers on both inlet and 
discharge and inspect internals to insure absence of 
rust. Check all internal clearances. Also, at this time, re-
move gearbox and drive end bearing cover and inspect 
gear teeth and bearings for rust.

Because of the completely enclosed unit design, location of 
the installation is generally not a critical matter. A clean, dry 
and protected indoor location is preferred. However, an out-
door location will normally give satisfactory service. Important 
requirements are that the correct grade of lubricating oil be 
provided for expected operating temperatures, and that the 
unit be located so that routine checking and servicing can be 
performed conveniently. Proper care in locating driver and 
accessory equipment must also be considered.

Supervision of the installation by a Roots Service Engineer is 
not usually required for these units. Workmen with experience 
in installing light to 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. Unit mounting must be solid, without strain or 
twist, and air piping must be clean, accurately aligned and 
properly connected.

Bare-shaft Units:

 Two methods are used to handle a unit 

without base. One is to use lifting lugs bolted into the top of 
the unit headplates. Test them first for tightness and fractures 
by tapping with a hammer. In lifting, keep the direction of 
cable pull on these bolts as nearly vertical as possible. If lifting 
lugs are not available, lifting slings may be passed under the 

cylinder adjacent to the headplates. Either method prevents 
strain on the extended drive shaft.

Packaged Units:

 When the unit 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 unit casing or mounting feet, 
or on any mounted accessory equipment. 

DO NOT

 use the 

lifting lugs in the top of the unit headplates.

Before starting the installation, remove plugs, covers or seals 
from unit inlet and discharge connections and inspect the inte-
rior completely for foreign material. If cleaning is required, finish 
by washing the cylinder, headplates and impeller thoroughly 
with a petroleum solvent. Turn the drive shaft by hand to 
make sure that the impellers turn freely at all points. Anti-rust 
compound on the connection flanges and drive shaft exten-
sion may also be removed at this time with the same solvent. 
Cover the flanges until ready to connect piping. 

Mounting

Care will pay dividends when arranging the unit mounting. This 
is especially true when the unit is a “bare-shaft” 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 gen-
erally produces the least satisfactory results. It definitely causes 
the most problems in leveling and alignment and may result in a 
“Soft Foot” condition. Correct soft foot before operation to avoid 
unnecessary loading on the casing and bearings. Direct use of 
building structural framing members is not recommended. 

For blowers without a base, it is recommended that a well 
anchored and carefully leveled steel or cast iron mounting 
plate be provided. The plate should be at least 1 inch (25 mm) 
thick, with its top surface machined flat, and large enough to 
provide leveling areas at one side and one end after the unit is 
mounted. It should have properly sized studs or tapped holes 
located to match the unit foot drilling. Proper use of a high 
quality machinist’s level is necessary for adequate installation.

With the mounting plate in place and leveled, set the unit 
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 rocking. Place half of this under each of the diagonally-
opposite short feet, and tighten the mounting studs or screws. 
Rotate the drive shaft to make sure the impellers turn freely. 
If the unit is to be direct coupled to a driving motor, consider 
the height of the motor shaft and the necessity for it to be 
aligned very accurately with the unit shaft. Best unit arrange-
ment is directly bolted to the mounting plate while the driver 
is on shims of at least 1/8 inch (3mm) thickness. This allows 
adjustment of motor position in final shaft alignment by varying 
the shim thickness.

Aligning

When unit and driver are factory mounted on a common 
baseplate, the assembly will have been properly aligned and is to 
be treated as a unit for leveling purposes. Satisfactory instal-
lation can be obtained by setting the baseplate on a concrete 
slab that is rigid and free of vibration, and leveling the top of the 
base carefully in two directions so that it is free of twist. The slab 
must be provided with suitable anchor bolts. The use of grouting 
under and partly inside the leveled and shimmed base is recom-
mended.

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