Category Archives: accesory equipment

Data Plates for UN Portable tanks (T11, T20, T22, T50)

Posted on June 6, 2017 | Leave a comment

Question:  “My tank is missing the data plate. What do I need to do in order to get another one?” 

Tank Guru: 

Each tank container used in international service needs to have the data plate that was affixed by the original manufacturer (or a replacement copy), a CSC Safety Approval plate, and a TIR/Customs plate.  The manufacturer’s plate includes key information regarding the design pressure and temperature, shell thickness, original hydro test date and last test date, and the approvals to which the tank was designed and constructed.  Additionally, for certain high-pressure tanks there might also be an ASME Code plate or a product plate that shows the list of substances approved for transport in the tank.

Most newer ISO tanks have a consolidated data plate that includes all of the manufacturer’s details as well as the CSC and TIR approvals.  If the data plate is lost or damaged in such a way that it’s not legible, you should affix a replacement plate that has been engraved with the original information — and then reviewed and stamped by the class society surveyor who carried out the last periodic test.  Replacement plates are available through tank container repair facilities or select parts suppliers:

http://www.perolousa.net/Combination_Replacement_Plate_for_MFG_DataCSCCustoms_-_8__x_20__Stainless_Steel/p733948_3684161.aspx

http://www.perolousa.net/Replacement_Plate_for_Manufacturers_Data_-_8__x_12__Stainless_Steel/p733948_3684051.aspx

http://www.perolousa.net/Replacement_Plate_for_TIRCustoms_-_4__x_8__Stainless_Steel/p733948_3684133.aspx

http://www.perolousa.net/Replacement_Plate_for_CSC_Safety_Approval_-_4__x_8__Stainless_Steel/p733948_3684080.aspx

 

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Posted in data plates, tank testing

container weights

Posted on May 9, 2016 | Leave a comment

Question:  “We mounted a mixer and some other equipment to our tank container.  This added equipment also added weight, so now the markings on the tank are incorrect.  What should I do?” 

Tank Guru:  Now that the International Maritime Organization (IMO) has introduced the Safety Of Life At Sea (SOLAS) regulations for Verified Gross Mass (VGM) of containers, there will continue to be increased scrutiny of container weights — especially when loaded, but also when empty.

It is key to have an accurate starting point, knowing what the empty weight of the container is before cargo is added.  If you have reason to believe that the actual weight of the container doesn’t match the tare (empty) weight that is stenciled on the tank, then we recommend re-weighing the tank.  First ensure that it is completely emptied of product, then have it weighed at a certified truck scale or comparable.  Once you know the weight, grind and re-stamp the data plate to correct both the tare weight and net payload, and replace any corresponding decal markings as well.

There are a lot of reasons that the tare weight on a tank container can change from its originally declared weight.  More common reasons include the installation of baffles, or the addition (or removal) of insulation and jacketing.  It is important that when changes are made, the markings are also updated accordingly.  People will make assumptions based on a container’s markings, and  improperly declared weights have been a factor in previous incidents involving ship safety.

Thanks for the question!

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Posted in accesory equipment, tank specifications

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80% filling ratio

Posted on July 5, 2013 | 2 comments

Question:  “We have a customer that wants to load a 1.17 SG product in 24000 liter tanks.  Because the product will solidify in transport as it cools, a representative from one of the Class Societies said it would be OK. 

The problem we see is that once the product arrives overseas and is heated at a depot prior to being delivered to the customer, it will no longer be solid and we believe it will no longer meet the viscosity requirements in IMDG 4.2.1.9.6 that allow you to ignore the 80% fill rule.  But the Class Society representative says that the IMDG viscosity criteria is at 20° C, and since we are having to heat the product above 20° C in order for it to be viscous, therefore we are in luck.”

Tank Guru:  His logic makes sense; however it sounds like complying with the letter of the law but not the spirit of the law.  If the rule is there to prevent a dangerous slosh and surge situation, but you dodge the rule because ‘had the product been cooler it would have been less volatile’ — then good luck defending that position in a court of law if there is a rollover accident resulting in death or injuries.

I think you should convince your customer to use 21000 liter tanks, which will generally have a lower tare weight than larger tanks, and allow for slightly more payload anyway.      #CommonSenseSafety

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Posted in Russell Harrison, tank baffles

Pounds-per-Gallon rating

Posted on October 9, 2012 | Leave a comment

Question:  “On our tank trailers, we have a pound-per-gallon rating.  Is there a rating for this on our tank containers?  Do we have a maximum pound per gallon rating?”

Tank Guru:  There is a definitely a maximum cargo weight you can carry, but the terminology in the tank container industry is a little different from the tank trailer industry, at least in the U.S.

For a tank container it is based on the Maximum Gross Weight (MGW) of the tank.  For instance, on many new tanks the MGW is 36000 KG or 79,365 lbs.  If you subtract from that the tare weight of 7,500 lbs. for a representative 24000 liter T11 tank, you would have a Maximum Payload carrying capacity of 71,865 lbs.

So if you filled that 24000 liter tank to the minimum safe-transport level of 80% you would have a payload of 19200 liters or 5,072 gallons.  Therefore the cargo could weigh up to 14.169 lbs. per gallon (71,865/5,072).  Now, you could never legally scale a load that heavy, but if you could the tank could handle it.  So in theory, that would be the pound-per-gallon rating.  In actual practice, you will be shipping loads of lighter density products in 24000 liter tanks (and probably to a higher filling ratio), but you can still use the same math for any sized tank and its actual MGW (less its actual tare weight).  Or, you could even use 24000 liter tanks at a lower filling ratio if baffles are installed — but just don’t forget to include the weight of any added baffles to the tare weight of the tank (because of the reduction to the payload capacity).  Hope that helps!

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Posted in tank baffles, tank specifications

level gauges for portable tanks

Posted on June 2, 2010 | Leave a comment

Question:  “What are the possible alternatives of level gauges we could install on our T11 24000 liter tanks.  Would a Scully system work for this?”

Tank Guru:  Scully systems are mainly intended just as overfill protection (high-level alarm) and do not provide a continuous indication of the product level.  When considering level gauges, the options are somewhat limited on portable tanks because of the lack of electrical power, and the need to have something that will hold up to the rigors of transportation service (shock, vibration, etc.).  Not to mention that in a stainless steel chemical tank, most customers are going to want a gauge with all SS wetted parts.  

So there are basically 2 practical options: float gauges, and ultrasonic or radar technology.  There are a handful of float gauges available for transport tanks that vary from basic mechanical devices which have a long arm inside the tank with a stainless steel float that magnetically operates a simple dial (indicates percentage of tank volume); to a precision gauge where the float travels up and down a sender bar which is calibrated to display the actual volume of liquid inside the tank (either liters or U.S. gallons).   

Another option is the radar gauge, and as with the float gauge there are a couple of different ways you can go – either guided wave radar or microwave loop (non-contact).  There are pros and cons of one technology versus the other, and a lot of it depends on what will be transported in the tank and whether you have the ability to anchor the probe used in a guided wave system to the bottom of the tank; but in general one big advantage of radar systems over the float gauges is that there are no moving parts.  The disadvantage is that these systems typically cost more than a float gauge.

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Posted in accesory equipment, level gauges, tank specifications