Chapter 22 - Installation And Levelling Flashcards
Why is proper installation, levelling, and alignment vital to satisfactory machine operation?
- following the proper steps alleviates many maintenance problems and extends the life of the equipment
- studies have traced 70% of mechanical breakdowns to misalignment
How are machines maintained in alignment during operation?
- proper installation onto baseplate / bedplates when driver-driven units share a common mounting
- machines not sharing a common mounting can be installed on soleplates / sub-bedplates, which are set into and anchored to the foundations
- independent machines are mounted directly onto a floor or foundation
Define the following:
- primary equipment
- the first unit of machinery set into place
- examples - pumps, conveyors, compressors, refiners
- most cases, referred to as the driven unit
Define the following:
- prime movers
- convert potential energy input of varying kinds into a mechanical form to drive other machine units
- referred to as drives or drivers
- examples - electric motors, steam turbines, and combustion engines
- usually the last machine unit to be aligned
Define the following:
- transmission units
- transmit mechanical energy from a prime-mover to a driven machine
- usually increases the torque and reduces the speed
- examples - gearboxes, differentials, VSD’s
- for alignment purposes, may be referred to as a driven or a drive unit
- a transmission unit for multiple-units is usually regarded as the primary unit and it installed first
Define the following:
- foundation
- main support on which a machine rests
Define the following:
- dowel
- straight or tapered (1/4”/ft) pin preferably with jacking (removal) nuts
- used to ensure permanent location and alignment of the machine to its base
- two dowels are usually used in each unit and located at diagonally opposite corners
Define the following:
- bench marks
- points of reasonably permanent character
- established by a surveyor to known elevations
- used as reference points in surveying and by millwrights for levelling machinery to elevation
Define the following:
- datum points
- known points from which any reckoning (measuring) or scale starts
- necessary to correlate measurements used to determine elevations and horizontal positions for different locations
Define the following:
- datum plane (level)
- horizontal plane from which heights, and depths are measured
Define the following:
- piano wire
- wire with very high tensile strength
- may be drawn extremely taut, giving a straight true line that does not stretch, loosen, or sag
- used as reference or control lines in three dimensions for machinery layout and installation
What operating principles of rotating machinery should the installer understand?
- machine function
- fitting procedures
- mounting
- machine mechanisms
- lubrication
- bearings
- transmission
- alignment
- seals
- rigging procedures
- guards
During installation of a multi-unit machinery set, which unit is usually set into place first?
- primary equipment is the first unit of machinery set into place
- followed by the transmission unit (sometimes primary unit)
- last to be installed is the drive unit
What maintenance procedures should followed after receiving, and prior to, installation of on-site machinery?
- upon arrival at the site, inspect the equipment to ensure that it is in good condition. Report any damage or defects. Also check packing slips for deficiencies
- check the manufacturer’s recommendations and owner’s requirements as to storage, locations, recommended lubricants to protect against rust, etc.
- fill bearing housings, gear reducers and any other oil-lubricated parts of the equipment with oil. Usually a light flushing oil containing a rust inhibitor is used
- examine equipment with openings, such as pumps, fans, refiners, compressors. Remove any foreign matter and seal the openings covers to prevent contamination
- unless otherwise specified, rotate the shafts of large units of rotating equipment at least once a month. Do this whether the equipment is in storage or on its permanent mounts.
What procedures should be followed during rigging and handling of machines?
1 - plan the move from the storage area to the final place of installation. This ensures that no unforeseen problems arise during the move.
2 - review the lifting specifications, such as, equipment weight, location of lifting lugs or special lifting considerations
3 - protect all machined surfaces from damage that can be caused by rigging equipment and attachments
4 - lift the load so that it is balanced and oriented in the required installation position
What installation procedures must be followed for warranty requirements?
- manufacturer’s specifications provide information about:
- installation
- alignment
- testing
- calibration
- lubrication
- start-up
- test-running
How are the machine and base prepared, prior to placing the machine on the base?
1 - before it is placed, inspect and make needed modifications to the equipment (this should be done prior to transporting the equipment to its prescribed location)
2 - review mounting method to be used for the machinery. Determine if it is the be mounted to the foundation, direct to the floor, or on an adjustable mounting
3 - lay out the machine’s position in relation to existing equipment (or blueprint) by establishing centrelines and reference lines
4 - prepare the mounting surface. This includes installing anchor bolts for baseplate, soleplate installation, levelling and grouting
What course of action is to be taken after the machine is moved into place?
1 - rig the machinery and set it in place
2 - fit the couplings, sheaves, sprockets and other field mounted equipment to each unit
What are the requirements for setting the primary unit?
1 - check the bearing clearances and remove locking devices on the primary unit
2 - position, level, and set to elevation the primary equipment
What are the requirements for setting the transmission and prime mover units?
Transmission
1 - check the bearing clearances and remove locking devices on the transmission unit
2 - rough align the transmission unit to the primary unit
Prime mover
1 - check the bearing clearances and remove locking devices on the prime mover unit
2 - rough-align the drive unit to the transmission unit or primary unit
What are the requirements for connecting piping and other attachments to the machines?
1 - connect all piping chutes and other attachments and check their alignment for stresses etc. so that no strain is placed on the machine
2 - disconnect from the equipment all the piping chutes etc. Adjust the piping etc. fro any misalignment between them and the equipment
3 - precision align to the tolerances specified in the manufacturer’s specifications
4 - if attachments cause misalignment from the specified tolerances, the attachments should be adjusted to eliminate these forces; sprockets and sheaves should be in line and parallel to one and another
What steps are involved in lubricating, powering, and testing the machines?
1 - remove flushing oil from equipment. Install the lubricant according to the specifications supplied by the engineer or vendor
2 - complete the installation of the power source for the prime mover (electricity, steam, etc.). Install other electrical and instrumentation interfaces
3 - test run the prime mover. This includes such steps as checking the direction of rotation doing a load test
4 - connect all drives to the primary equipment
5 - lubricate coupling, chains, and other drive components where necessary
6 - install all equipment guards and platforms (work stations) in accordance with design standards and to WBC requirements
How are the stages of installation and testing recorded?
- recommended that equipment tags be used
- as each stage of the installation is completed, that section of the tag is filled in
- it may be necessary to report directly to your supervisor the completion of each step and file equipment reports to be checked by the engineer
What are the requirements for mounting and securing machinery?
- must support the machine without distorting it
- absorb vibrations
- secure the machine at its correct location and level
What methods are used to mount machines?
- mounted directly to concrete pads or floors
- set on concrete pads or floors using special mountings
- mounted on structural steel supports or steel floors
- on soleplates
- on a baseplate
when mounting on structural steel:
- use a base plate
- make the thickness of the base equal to or greater than the thickness of the unit feet
- extend it under the entire unit as shown
- bolt unit and base plate securely to steel supports
Describe the following:
- adjustable machinery unit
- machinery is mounted on devices called machinery mounts or machinery levellers
- anchor bolts are not generally required with this type of mount
- the levelling features incorporate double wedges that enable a machine to be levelled to precise limits in a minimum amount of time
When using this type of mount:
- ensure that it is clean and greased so that it does not jam
- always use mountings that are designed to carry the load of the machine
Describe the following:
- self-levelling pads
- used where the floor is not flat, smooth, or level
- incorporate a rocker in the design to compensate for the misalignment
Describe the following:
- vibration isolators
- prevent machine vibrations from being transmitted to adjacent equipment
- prevent the amplification of internal stresses which cause misalignment and wear of machine elements
various devices used:
- simple felt pads between baseplate and floor
- plain spring mount
- shock-dampeners
What are the requirements of a foundation?
- be solid and rigid
- footings must be firm and large enough to carry the distributed weight safely
- should rest on a firm grounding such as rock, hard clay, well-compacted sand or gravel
- if ground is less firm, weight should be distributed over a larger area
- if soil is wet or soft, pilings may be needed, or vertical supports
How are foundations built to achieve their requirements?
- constructed of solid or reinforced concrete
What does a millwright check on a foundation?
- positions of anchor bolts should be checked against the locations of the anchor bolt holes in the machine (as built)
- should errors be found, they must be recorded and the necessary modifications made to the baseplate (or soleplate) and/or foundation anchor bolts
Why is a machine foundation usually constructed lower than the bottom of the baseplate or soleplate?
- minus elevation by 19mm to 38mm
- 38 mm is a practical thickness for shimming and grouting
- eliminates concern about foundation shrinkage
- provides space for shimming to elevation
- provides space for grouting the baseplate or soleplate
How is vibration controlled?
- use large, well designed foundations
Foundation may also be isolated from the surrounding floor by means of:
- dead air apaces
- vibration insulators (felt, cork, insulation, etc)
What are the purposes of anchor bolts and hold-down bolts?
Anchor bolts
- used to firmly secure the machine baseplate or soleplates to a concrete foundation
- also used to fasten machines directly to concrete floors
- commercially available anchor bolts referred to as cinch anchors
Hold-down bolts
- used to secure machine units to the baseplate, soleplates, or structural steel foundations