Preface
In the last decade the world has seen a rapidly developing manufacturing trend, which gave the rise to many new racking suppliers around the globe, especially in China. There are literally hundreds of factories in China at present all producing pallet racking and boasting that their product meets the latest FEM & EN directives. All this comes with of course very attractive prices, while at the same time luring the customer into a false sense of security that the product is of high standard by having glossy brochures and nice looking websites. This is not to say that everything coming out of China is of poor quality as most consumer products are, as we all know manufactured in China. However joining the storage system manufacturing industry needs prior and in depth knowledge of structural statics and required norms to enable safe design. This should also be reflected in the product price of course as we will illustrate further in this article.
Why FEM and EN standards are so important
In today’s market with land costs rising it is not unusual to see selective pallet racking with top beams above 10m and Narrow aisle operations above 14m. Whilst most operators are very aware of beam deflection which is easily visible, regrettably insufficient attention is given to the strength design and safe weight loading of the frame which can take up to 7-8 times a pair of beam loads.
Make no mistake; pallet racking is a dangerous affair. Lives are at risk on a daily basis during operation hours with forklift drivers negotiating tight aisles, turning into and out of the rack with considerable speed and carrying heavy loads.
FEM regulations have been adopted as the Industry standard; these standards are now being adapted to suit all Euro Norm standards to be known as the CEN EN (European committee of standardization).
For more information please visit http://www.cen.eu/. Companies failing to meet these standards will not be allowed to sell into the EU.
With this in mind it is of paramount importance to ensure that the offered system does indeed meet these standards and directives as dictated by CEN. The standards affecting pallet racking are:
EN 15620: Tolerances, deformations and clearancesEN 15635: Application and maintenance of storage equipmentEN 15629: Specification of storage equipment
All pallet racking manufacturers should adhere to these standards and they should have proof that they do so. Bear in mind that the certificate should be issued by an independent body.
Don’t be afraid to ask for these certificates as accepting that the product is FEM compliant because it says so in their literature could prove a regrettable decision.
What to look out for in selecting a pallet racking system
Usually when a client is presented with a quotation they look at the following (in this order):
Cost
Capacities
Beam deflection
All racking manufacturers can claim that their bay load can take X tons and that their pair of beams can take Y tons; but there is more to it than that.
In our opinion, the following points should be taken into account:
Supplier history and references
Proof of FEM tests
Grade of steel used
Yield point (dependant on grade of steel) – denoted as YP
Tensile strength (dependant on grade of steel)
Mid point beam deflection
Safety factor
Connectors
Powder coating standards
Sections of the beams and frames
Frame and beam capacity loading tables
We will explain each point individually
Supplier history and references
Supplier pedigree is very important as is a list of references both internationally and in your country. Ask to see references of installations of multi national organisations, an on-going customer list and where appropriate, a case study.
A company with an established history will guarantee you spare parts for your future extensions as it will continue to be in operation. Will a relatively new supplier be around in 3 years time, especially with signs that the global economy is slowing down? Can you sue them if you find out that indeed they haven’t adhered to FEM standards and a collapse has occurred, or that they have been using lead in their paint? Do they provide product or public liability insurance?
Proof of FEM tests
Whilst many companies claim to conform to these and all other published standards, the fact is they have never had their product tested. Any testing is accompanied by sets of photographs’ showing and detailing the various tests with graphs and reports. If the product has been tested then the reports / photographs are available. If a company can not produce this proof then draw your own conclusions!
Grade of steel
One of the most important elements often overlooked regrettably, is the raw material itself. Rolling pallet racking requires little expertise and can often be done at a low investment meaning that more and more companies were jumping on the bandwagon.
Steel grades around the world vary in according to region but while certain ones are widely available and can be purchased on the spot in standard coil widths, higher grades that are usually required for frames have to be ordered on a 3-month lead time in some countries, thereby forcing local manufacturers to use lower grade steel with lower yield points and tensile strengths (we will explain these 2 items further down).
Don’t be fooled by some manufacturer’s samples being larger/thicker than another’s, and thinking that it must be a stronger product. This is often done to compensate for the fact that the steel is of lower quality. Most manufacturers in China use mild steel, so make sure you ask and challenge that the stated material is indeed the one used.
Yield point
All metals have an elasticity property, meaning that if a force is applied on a metal bar for example, it will deform and then return to its original position when that force is retracted. The Yield point is the amount of force that will cause the material to deform beyond the point of its ability to return, thereby causing a permanent deformation.
The steel grade should dictate this value.
Tensile strength
Tensile strength is the property defining the permanent deformation of the material when a stretching force is applied. Again the steel grade should dictate this value.
Midpoint beam deflection
The maximum mid point deflection of a beam in accordance to EN 15620 or FEM 10.02.02 should not exceed 1/200 of the beam length. This means that the beam deflection from the horizontal position is allowed to deflect by 2700/200 = 13.5mm when under load, thus returning to its original position when the load is removed.
So when the beams are loaded you should be able to see a slight "bending".
Ensure that this is not a greater than 1/200 as that would give a higher deflection than the EN allowance dictates; it would also show that the beam capacity is higher when in fact there is more overloading. Proper charts should indicate capacities at defined deflections.
Safety factor
Safety factor is applied to ensure the safety of the installation, and in accordance to FEM 10.02.02 this value is 1:1.55, i.e. 55% on system and 92% on yield calculated to 2nd order analysis.
The published safety factor in China is 30% overload to 1st order analysis, thereby not EN compliant and many manufacturers (even European ones manufacturing in China) lower their factor to be more competitive pricewise.
Again, make sure you get proof that the product is indeed FEM tested and is not just claimed. It could be that the product is only suitable for the Chinese market and not the European one.
If you have a cheap quote from a European manufacturer, it is most likely that the product is now made in China for the Chinese market and that it should not be exported to Europe.
Connectors
The fixitivity of the end connectors is a critical feature to the calculation of the loading tables. Beams with good connectivity to the post will help support damaged uprights’ until racks can be safely off load and repaired. Look for 5 pin (50mm pitch) connectors which is what the European manufacturer’s are manufacturing, in contrast with the standard Chinese 3 pin connector at a 75mm pitch which will twist/rotate under load.
Powder coating standards
Powder coating is another area to question in that most Chinese manufacturers use high lead paint or powder in order to give the product a shiny finish. This would not be accepted in a warehouse where the storage of food, beverages and pharmaceuticals are present, as every time the pallet is scraped over the beam, small particles of lead are sprinkled over the pallets below.
Ensure the supplier uses lead-free powder coating. Ask for certificates!
Sections of the beams and frames
Ask the supplier for all the various post and beam sizes to see the variety of loading capabilities. Even bracing and footplate sizes are important as they can add to the overall system strength considerably. All the various sizes should be depicted in their loading charts for you to make a comparison between suppliers (including a reference to the beam deflection as mentioned above!).
For example if one supplier’s beam is 125mm high and claims a load of 3.6 tons per pair, and another needs 140mm beam to achieve the same load, ask yourself why. It is likely that the steel is of lower grade.
Compare frame loads carefully in relation to the position of the 1st beam from the ground. The section of the 1st beam level is also critical to the frame load; the bigger the section the higher the capacity.
Frame and beam capacity loading tables
This is always an interesting question; how do manufacturers establish their loading charts?
Loading tables should be a result of FEM compliant testing by a qualified independent body. The loads are then calculated using 2nd order analysis by use of a highly complex procedure which requires a special computer program.
This stresses again the point that you should ask the supplier for an FEM certificate.
Summary
We hope to have raised your awareness of what to look out for when considering the purchase of pallet racking. It is easy to be tempted by a supplier who offers a stupidly low price and not take into account all the above points that will constitute a safe working environment for you and your employees.
Spend time investigating the technical details and comparing like for like without disqualifying quotes based on price. Question the supplier and ask for proof of what they are claiming. If they can’t provide proof on EN/FEM compliancy then walk away as it is likely that it is not. EN compliancy is a costly and complex process and is not acquired that easily.
Research and product testing on a regular basis in order to ensure that the product is always inline with the latest directives is of paramount importance, which also adds to the overall product cost.
Remember... the racking business, especially on high volume projects is a low margin one, and if one supplier’s price is higher than the other’s there is usually a very good reason for it.
On a last note, remember that companies showing you ISO 9001 certificates doesn’t mean that their product is safe; ISO compliance is the documentation of procedures and processes and has nothing to do with safety.
Simply put, you get what you pay for.