Crane Service Classifications

 According to different standards, crane service can be divided into different classifications. Usually, the most frequently used standards are ASME, CMAA, HMI, ISO, CEN EN, FEM and OSHA. In the following paragraph, it will put in length on crane service classifications based on CMAA (Crane Manufacturers Association of America), HMI (Hoist Manufacturer’s Institute), FEM (Federation Europeenne de la Manutention), and AISE Crane Service Classifications, and their comparisons for your sake to select the proper crane machine for your application.

CMAA crane service classifications

CMAA classifies crane services into six classes: A, B, C, D, E, and F, shown in the following paragraphs:

Class A Infrequent Service

Crane comes into class A has the features:

• Handling loads at slow speeds with long die periods between lifting.
• Capacity loads may be handled for equipment installation or maintenance.
• Applications: powerhouse, public utilities, turbine rooms, transformer stations, motor rooms.

Class B Light Service

Crane comes into class B has the features:

• Dealing light loads from no loads to full rated loads occasionally with slow speed.
• 2 or 5 lifts per hour, around 10 feet per lift on average.
• Application: Light assembly operations, service buildings, light warehousing, etc.

Class C Moderate Service

• Crane comes into class C has the features:
• Dealing loads with no heavier than 50 percent of the rated capacity on average
• 5 to 10 lifts per hour, around 15 feet.
• Applications: machine shops, paper mill machine rooms, etc.

Class D Heavy Service

Crane comes into class D has the features:

• Dealing loads around 50 % but of the rated capacity constantly,
• High working speed, 10 to 20 lifts per hour around 15 feet.
• Applications: Heavy machine shops, foundries, fabricating, plants, steel warehouses, container yards, lumber mill, etc.

Class E Severe Service

Crane comes into class E has the features:

• Handling loads around rated capacity throughout its life time.
• 20 and more lifts per hour at or near the rated capacity.
• Application: Cranes with magnet, bucket loading devices are used in scrap yards, cement mills, lumber mills, fertilizer plants, container handling, etc.

Class F Continuous Servers Service

Crane comes into class F has the features:

• Handling loads around rated capacity under severe service conditions throughout its life.
• Special care to maintenance is required.

FEM crane service classifications

According to FEM standards, crane services can be grouped in the classes of Light, Medium, Heavy, and Very Heavy.
Factors determines the crane services group based on FEM standards are:
1. Load spectrum, which presents the frequency of loads with maximum and smaller lifting capacity during examined time.
2. Number of hoisting cycles during the lifetime of crane.
Example of different load spectrums:

AISE crane service classifications

AISE also gives its method to calculate the crane services class, which is generally described in as follows:

• Crane Service Class 1 (N1): Less than 100,000 cycles
• Crane Service Class 2 (N2): 100,000 to 500,000 cycles
• Crane Service Class 3 (N3): 500,000 to 2,000,000 cycles
• Crane Service Class 4 (N4): Over 2,000,000 cycles

Further AISE describe the different Load Classes as:

• L1= Crane hoists light loads normally but rated load occasionally.
• L2= Crane hoists loads about 1/3 crane rated loads capacity normally but rated loads rarely.
• L3= Crane hoists loads between 1/2 and 2/3 of crane rated capacity normally but rate loads fair frequently.
• L4= Crane hoists loads with lifting capacity regularly.

The crane services class of a crane is determined as the following diagram based on the above load classes and load cycles.

HMI hoist service classifications

HMI also provides a method based on the relative significance of duty cycle ratings for different types of electric hoists. HMI hoist service classifications is provided in the following table:

Note: It requires various additional information of the hoist application conditions to determine the duty cycle.

Comparison of different Crane service classifications

Different crane service classifications are given based on different standards. In order to give you a better understanding to the different crane service classifications, the comparison on CMAA, FEM, ISO, and HMI crane service classification are shown in the following table:

 Conclusion

Various crane service classifications based on different standards are various ways to help you to select the proper crane or hoist for you application. Do remember when choose the crane or hoist for your application, you have to consider the following factors which need to confirm with your crane or hoist manufacturer:

• Hourly lifts and trolley and bridge movements on average.
• Length of each movement on average.
• Estimated weight of loads required to be lifted each time on average.
• Total operating time per day.

5 Ton Freestanding Jib Crane with Electric Chain Hoist for Sale

Freestanding jib crane for sale to Philippines, consists of column, swing jib, electric hoist, drive device and electrical control system. The bottom of column is fixed on the concrete foundation by the anchor bolts, driving device is driven by the motor to rotate swing jib, and the electric hoist reciprocates and runs on swing jib.

What we can do for our customers:

• 5 ton pillar jib crane with chain hoist has been designed for freestanding installation on the building floor.
• This workstation application of jib crane provides a slew range of 360° according to our client’s request. 
• The low-built design allows high hook positions for optimal use of the available building space.
• In addition to the comprehensive standard design, Dongqi crane machine pillar jib crane may adapted individually by making use of useful additions such as electric slewing, electric hoist travelling or mobile control.

Free standing jib crane for sale specifications:

• Arm Length: 3m
• Lifting Capacity: 5 ton
• Lifting Height: 3m
• Slew Angle: 360°
• Slewing Speed: 0.7 r/min
• Electric Hoist: chain hoist with motor trolley
• Power Supply: 220V, 50HZ, 3phase
• Control Mode: Pendent pushbutton control
• Free standing jib crane design can be customized according to your request.

Why customers choose Dongqi jib cranes?

• Precision tapered roller bearings in top pivot and trunnion assemblies provide smooth operation and long life.
• Independent head assembly installed separately from the boom for easier installation.
• These jibs and components are built and assembled with jigs and fixtures to ensure easy installation.
• Recessed bearing assembly allows greatly reduced clearances needed for installation.
• Bolted head/boom connection permits separate installation and provides maximum lift for the hoist.
• In-head, totally enclosed, bottom entry collector assembly allows for the option of easily adding power to the hoist for 360 degree rotation at the time of or after purchase.
• Optional power rotation makes moving heavy loads even easier.
• Suitable for underneath traveling cranes, in open areas where it can serve several work stations, in outdoor applications such as loading docks, or in machining and assembly operations where it can be overlapped with other jibs to provide staged operation.
• Allows operators to position loads precisely, effortlessly and efficiently.
• Safety head retaining pin provides the resistance to accidental upward dislodgment of the head.

How to choose the right jib crane for your application?

When selecting a jib crane that matches your individual requirements, it’s important to think about your operation type, facility structure, cost of the unit and installation, and any necessary options, like motorized rotation, box track festooning, and rotation stops.


 
More specifically, the following factors should be considered when choosing the right jib crane for your specific application:

• Capacity: The maximum weight of the application should never exceed the rated capacity/design weight. Ensure your manufacturer is using design criteria that allows the least amount of deflection so as not to hamper the performance of the crane.
• Height Under Boom: The distance from the floor to the underside of the boom. It’s important to consider the size of the hoist and the amount of lifting distance when deciding on your HUB.
• Overall Height: The height to the highest point on the crane after installation. Any attachments, such as electrical entry, should also be considered to provide full rotational potential and freedom from overhead obstructions.
• Working Span: Distance from the floor to the underside of the jib crane’s boom.
• Boom Rotation: Freestanding and mast-type jib cranes provide 360-degree rotation. Wall-mounted jibs offer 200-degree rotation, and articulating jibs provide 360-degree rotation on the inner and outer arm (freestanding and ceiling-mounted) and 360-degree rotation on the outer arm and 200-degree rotation on the inner arm (wall-mounted).
• Power Requirement: How much power is necessary? Is the power for rotation, trolley, hoist, or all three? How will the power be supplied? Bottom or top entry? Electric or air?
• Weatherization: Does the system or its Electrical components need to be weatherized for outdoor use?
• Installation: Freestanding jibs require reinforced concrete foundations which insure proper installation.

Bridge crane buying tips help you gets ideal bridge crane

 Before bridge crane purchasing, there are many factors needs to be considered to buy an ideal bridge crane. Your purchase is typically to improve productivity and safety within your facility. Therefore you really need to take several things into account prior to the bridge crane purchasing. Lowest bid does not work in the bridge crane industry. There are too many bridge crane variations, safety requirements, and technological features available. Before you invest your money into a new bridge crane, take into account these ten items that will not only save you money but you will invest in the best bridge crane for your application.

Typical double girder bridge crane

 

1. Know Your Application

This is the most important thing to know over anything else. Depending on the application could change many of the deciding factors on what kind of bridge crane you will need.

For example certain chemicals can make plastic brittle or accelerate metal corrosion. Cutting oils can make neoprene and PVC brittle. Heat and moisture can cause your motors to overheat. You will not pick the right bridge crane without the crane company knowing what the application is. Your crane will need to come with certain components depending on its application. To know your application you will need to know what you’re picking up, and the environment in which the bridge crane will be used. Added components will be required for areas with heavy dust, humid, high or low temperatures, outdoor, indoor, chemical exposure, Light, and even altitude can affect the bridge crane. Outside of the standard range, additional components will be required.
Look out for these items on your application.

• Standard Altitude is Below 3280ft (Altitude can affect cooling of electronic components and not allow heat dissipation)
•  Standard Temperature Range is 32˚F to 104˚F
•  Standard Humidity is below 90%
•  Outdoor Applications will require features to prevent damage during rain, snow, ice, heat, wind, and ultraviolet radiation.
•  Corrosive or Explosive Chemicals/ Fumes will require added features
• Heavy dust environments from cutting will require protective added features
•  Heat can liquefy lubricants, and affect motors, and Electrical components
• Cold can freeze lubricants, crack plastic components, and electrical parts

• Drastic temperature changes can cause condensation and short out electrical components and cause corrosion

 

2. duty cycle

The bridge crane’s duty cycle is going to depend partly on the application. If the crane is a production bridge crane it will probably need a heavy duty cycle. If it is a maintenance bridge crane or a bridge crane used for shipping then the cycle may be shorter. You will need to ask yourself how often will this bridge crane will get used every hour and how often will it be lifting near full capacity? Depending on this, different components will be used to make your customized bridge crane. Electric motors have duty cycles and you want to make sure that your bridge crane has the right motor for the job. Picking a severe duty motor for a light duty application will just cause you to spend well over what is required for the application.
There are two standards bridge crane manufacturers go by when picking out the right duty cycle. FEM and CMAA. CMAA is the Bridge Crane Manufacturers Association of America and FEM is Federal European De La Manutention. This is the standards for design and manufacturing internationally of overhead traveling bridge cranes. Both specifications are written based on the input from the larger bridge crane companies. The difference is that FEM is worldwide while CMAA is the United States only. FEM will also separate each main part of the bridge crane (hoist, trolley, and bridge) while CMAA specs classify the bridge crane as a whole. To understand these classifications you will also need to understand what a lift or work cycle is. A work cycle is lifting the load, having a rest period where the trolley or bridge is moving, lowering the load, having a rest period again where the trolley or bridge may be moving, and then returning the hook to the starting position.

FEM Class Definitions

1Bm

•  Light Loads less than two hours per day (Occasional full loads, usually light load, Small fixed load)
• •Medium loads less than one hour per day (Occasional full loads, usually light load, Average fixed load)

1Am

• Light Loads less than four hours per day (Occasional full loads, usually light load, Small fixed load)
• Medium loads less than two hours per day (Occasional full loads, usually light load, Average fixed load)
• Heavy loads less than one hour per day (Repetitive full loads, usually average load, Heavy fixed load)

2m

•  Light loads less than eight hours per day (Occasional full loads, usually light load, Small fixed load)
• Medium Loads less than four hours per day (Occasional full loads, usually light load, Average fixed load)
• Heavy loads less than two hours per day (Repetitive full loads, usually average load, Heavy fixed load)
• Very heavy loads less than one hour per day (usually almost full loads, Very heavy fixed load)

3m

• Light loads less than sixteen hours per day (Occasional full loads, usually light load, Small fixed load)
• Medium Loads less than eight hours per day (Occasional full loads, usually light load, Average fixed load)
• Heavy loads less than four hours per day (Repetitive full loads, usually average load, Heavy fixed load)
• Very heavy loads less than two hours per day (usually almost full loads, Very heavy fixed load)

4m

• Medium Loads less than sixteen hours per day (Occasional full loads, usually light load, Average fixed load)
• Heavy loads less than eight hours per day (Repetitive full loads, usually average load, Heavy fixed load)
• Very heavy loads less than four hours per day (usually almost full loads, Very heavy fixed load)

5m

• Heavy loads continuous use per day (Repetitive full loads, usually average load, Heavy fixed load)
• Very heavy loads continuous use per day (usually almost full loads, Very heavy fixed load)