Nondestructive Testing with Bruker Handheld XRF Analyzers

Non-destructive testing or NDT – also called non destructive examination (NDE), nondestructive inspection (NDI), and non-destructive evaluation (NDE)  – with Bruker handheld XRF analyzers can be achieved in seconds or minutes for a broad variety of applications.  By contrast, other elemental analysis techniques, such as OES (Optical Emission Spectrometry) leave a spark mark on the alloys being analyzed; and ICP (Inductively Coupled Plasma) analysis or AA (Atomic Absorption) analysis are destructive to the sample.  Handheld XRF allows you to perform completely nondestructive testing on practically any material.

When it is crucial that materials not be marred in any way yet elemental analysis is required, nondestructive testing with handheld XRF guns make it possible for many manufacturers, retailers, distributors and consultants to remain compliant with regulations:

• Art Conservation and Restoration
• Consumer Products/H.R.4040 with the (S1 TITAN) XRF Gun
• Lead in Apparel with the S1 TITAN
• TPCH- Toxics in Packaging Clearing House Laws
• ASTM F-963 - The Mandatory Toy Standard
• RoHS- Restriction of Hazardous Substances
• Prop 65- Lead restricted from all products sold in CA
• Jewelry Evaluation - Precious Metals, Gold, Silver
• PMI Analysis
• Positive Materials Identification in Aerospace Alloys
• QA/QC for Alloys

There are also applications in industries where nondestructive testing is not required yet it makes life a lot easier if the sample is not destroyed and can be confirmed with back up analysis in a laboratory:

• Soil Remediation
• Mining Exploration

Whether you are striving to comply with regulations or conducting elemental analysis where nondestructive testing is necessary for optimum efficiency, handheld XRF analyzers from Bruker can get the job done, quickly, effectively and nondestructively.

Determine the Operating Group of the Hoist

General Comparison

Summarizing

To select correct crane duty, crane structure and mechanical components, the user must identify and pass on the following information to the supplier:

1. Average lifts and trolley and bridge movements made in an hour.
2. Average length of each movement.
3. Estimate the load lifted each time.
4. Total operating hour per day.

FEM SERVICE CLASS

To determine your crane duty group (according to FEM, Fédération Européene de la Manutention) you need following factors:

1) Load spectrum (Indicates the frequency of maximum and smaller loadings during examined time
period).

2) Class of utilization (This is determined according to number of hoisting cycles during lifetime of crane)

3) Combining these factors is how a duty group is selected.

Example of different load spectrums:

Calculate the Average Daily Operating Time

t = (2 x H x N x T) / (V x 60)

Where:

 H = average hoisting height (m or feet)
 N = number of work cycles per hour (cycle/hour)
 T = daily working time (h)
 V = hoisting speed (m/min or feet/min)

AISE SERVICE CLASS

AISE also provides for different service classes for cranes covered under AISE Technical Report No. 6, "Specifications for Electric Overhead Traveling Cranes for Steel Mill Service". Like CMAA, AISE also provides a numerical method for determining crane class based on the expected load spectrum. Without getting into the specifics of this method, AISE does generally describe the different service classes (load cycles) as follows:

1. Service Class 1 (N1): Less than 100,000 cycles

2. Service Class 2 (N2): 100,000 to 500,000 cycles

3. Service Class 3 (N3): 500,000 to 2,000,000 cycles

4. Service Class 4 (N4): Over 2,000,000 cycles

Further AISE describe the different Load Classes as

1. L1= Cranes which hoist the rated load exceptionally, and normally hoist very light loads

2. L2= Cranes which rarely hoist the rated load, and normally hoist loads about 1/3 the rated capacity

3. L3= Cranes which hoist the rated load fairly frequently, and normally hoist loads between 1/2 and 2/3 or the rated capacity

4. L4= Cranes which are regularly loaded close to the rated capacity

Based on the load classes and load cycles, the CMMA chart below helps determine the class of the crane.

HMI/ASME HOIST DUTY RATINGS

The following table provides an idea of the relative significance of the duty cycle ratings for the various electric hoists. Note that the duty cycle determination for a particular application involves obtaining a significant amount of additional information and expertly applying it to the intended use.

CLASSIFICATION OF CRANES

Crane Duty Groups

Crane duty groups are set of classifications for defining the use of crane. There are several different
standards where these groups are named differently. One may have heard names CMAA, FEM, ISO or HMI. They all have their own classification of duty groups but are still based on the same calculations and facts. Following is a short description of what a duty group means and what it is for.

A crane duty group tells which kind of duty the crane is for; the range is from light duty up to very heavy duty. It is vital to define the needs and estimate the use because of safety reasons and for to ensure a long working life for the crane. You can't put for example a crane designed for light duty into continuous heavy-duty work.

CMAA Crane Classification

As to the types of cranes covered under CMAA Specification No. 70 (Top Running Bridge and Gantry Type Multiple Girder Electric Overhead Traveling Cranes); there are six (6) different classifications of cranes, each dependent on duty cycle. Within the CMAA Specification is a numerical method for determining exact crane class based on the expected load spectrum. Aside from this method, the different crane classifications, as generally described by CMAA, are as follows:

ESSENTIAL PARAMETERS FOR SPECIFING EOT CRANES - Part 2

Hello Structural Engineering readers, how are u? Today we continued some more tips about the above topic for your further explanation.

Other than addressing the last post (see here) parameters, some specific conditions applicable to your application must be mentioned.

1) Do you need the use of a second hoist on the bridge crane? (This hoist may be used as an auxiliary hoist or be required in a process such as tilting/tipping. In case you are handling long materials, like steel tubes and plates, the best solution are to have a crane with two hoists (and hooks) for better stability of the load ensuring safe lifting).

2) What will the operating environment be (dust, paint fumes, outdoor, etc.)?

3) Is there existing cranes on the runway? Then, consider the use of a collision avoidance or collision warning system.

4) Do you require a catwalk on the crane for maintenance access?

5) What other accessories are required such as lights, warning horns, weigh scales, limit switches, etc.

Load is defined as the maximum working load suspended under the load hook. Load block and ropes are not included in the rated load.

The design load for the crane system is based on the rated capacity plus 15% for the weight of the hoist and trolley (capacity x 1.15) and an additional 25% for impact (capacity x 1.25) for a total design capacity x 1.4. (Note 25% impact factor is good for hoists speeds up to 50 fpm).

The capacity of crane is the maximum rated load (in tons) which a crane is designed to carry. The net
load includes the weight of possible load attachment. For example , a 1000 lb crane allow you to pick up a 1000lb load, provided the hoist weighs 150lbs or less and the hoist speed is less than 50 feet per minute.

Under no conditions should the crane be loaded beyond its rated capacity.

Note that the Crane test loads are typically specified at 125% of rated capacity by both OSHA and ASME.

ESSENTIAL PARAMETERS FOR SPECIFING EOT CRANES

Hii readers, today we will show you some tips how to select correct crane envelope that will fit in the building foot print, and the user must identify and pass on the following key information to the supplier before proceed with manufacturing process:

1) Crane Capacity  - The rated load, the crane will be required to lift. Rated load shall mean the
maximum load for which a crane or individual hoist is designed and built by the manufacturer and
shown on the equipment identification plate.

2) Lift Height - The rated lift means the distance between the upper and lower elevations of travel of
the load block and arithmetically it is usually the distance between the beam and the floor, minus the
height of the hoist. This dimension is critical in most applications as it determines the height of the
runway from the floor and is dependent on the clear inside height of the building. Do not forget to
include any slings or below the hook devices that would influence this value.

3) Runway Height – The distance between the grade level and the top of the rail.

4) Clearance - The vertical distance between the grade level and the bottom of the crane girder.

5) Clear Span- Distance between columns across the width of the building. Building width is defined as the distance from outside of eave strut of one sidewall to outside of eave strut of the opposite
sidewall. Crane Span is the horizontal center distance between the rails of the runway on which the
crane is to travel. Typically distance is approximate to 500mm less than the width of the building.
How much span a crane requires depends on the crane coverage width dictated by the application.
(According to the span and the maximum load handling capacity, the crane steel structure is
selected to be either a single or double girder crane construction).

6) Building Height - Building height is the eave height which usually is the distance from the bottom of the main frame column base plate to the top outer point of the eave strut. Eave height is the
distance from the finished floor to the top outer point of the eave strut. There must be a safety
distance between the top edge of the crane runway rail and the first obstacle edge in the building
(for example roof beams, lights and pipes).

7) Runway Length- The longitudinal run of the runway rail parallel to the length of the building.

8) Hook approaches - Maximum hook approach is the distance from the wall to the nearest possible
position of the hook. The smaller the distance is, the better can the floor area be utilized. Always
check which crane gives optimum hook approaches and when combined with the true lift of the hoist
you can utilize most of the available floor space. This is also termed as side hook approach.
End Approach – This term describes the minimum horizontal distance, parallel to the runway,
between the outermost extremities of the crane and the centerline of the hook.

9) Bridge, Trolley and Lift Speeds - The rate at which the bridge or trolley travels or at which the hoist lifts is usually specified in feet per minute or FPM. The crane operating speeds are selected to allow safe operation whilst using the pendant. Dual operating speeds, normally a fast and slow speed with a ratio of 4:1 are commonly used but for optimum control a variable speed control system is strongly recommended.

10) Electrical Requirements - Specify the circuit voltage shall not exceed 600 volts for AC or DC current. Ideally 480 volt, 3 phase, 60 hertz for US requirements. The runway power is usually by conductor bar and hoisting trolley by festoon cable. (refer section 6 for details)

11) Control Requirements - The control circuit voltage at pendant pushbuttons shall not exceed 150
volts for AC and 300 volts for DC. Other control options including radio control, free-floating pendant (festooned) or hoist-mounted pendant requirements must be stated.

Ok, thats all for today. We will learn some more in next post. Thank you for reading.