Howden Roots 412 HPT, Installation, Operation & Maintenance Manual

ISRB-2009, Rev. 02_17.

4

Installation 

Howden Roots blowers arrive without lubrication in the sump, 

see lubrication section for details.
Howden Roots blowers are treated after factory assembly to 

protect against normal atmospheric corrosion. The maximum 

period of protection is considered to be one year under 

average conditions, if shipping plugs & seals or not removed. 

Protection against chemical or salt water atmosphere is not 

approved. Avoid opening 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, following steps should be taken to ensure corrosion 

protection.
•  Coat intervals 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,  

IL. 60521.

• 

Paint shaft extension, inlet & discharge flanges and any 

other exposed surfaces with Nox-Rust X-110 or  

equivalent.

•  Seal inlet, discharge and vent openings. It is not  

recommended that blower 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 effectiveness.

•  Protect blower from excessive vibration during storage.

•  Rotate shaft three to four revolutions every two weeks.
• 

Prior to start up, remove flange covers on both inlet & 

discharge flanges and covers on vent opening and 

inspect internal clearances. Also, at this time, inspect 

gear box intervals thru breather location 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 preferred; however, an 

outdoor location will normally give satisfactory service. Impor-

tant requirements are that the correct grade lubricating oil be 

provided for expected operating temperatures, and that the 

blower be located so that routine checking and servicing can 

be performed conveniently. Proper care in locating drive and 

accessory equipment must also be considered.
Supervision of the installation by a Howden Roots Service 

Engineer is not usually required for these units. Workmen with 

experience installing light to medium weight machinery should 

be able to produce satisfactory results. Handling of  

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.

Mounting

Two methods are used to handle a unit. One is to install lifting 

lugs into the (4) 5/8-11 tapped holes in top of the unit. Test the 

lifting lugs for tightness and potential fractures by tapping with 

hammer. In lifting, keep the direction of cable pull on these 

bolts as nearly vertical as possible. If unable to use the tapped 

holes in top of unit for lifting, lifting slings or a special cradle 

may be passed under the unit for vertical lift.