Anybody Know the MAWP of a Tanker Truck?

[KernOily]

Hi guys. Not exactly sure where to post this. so starting here. Anybody know what the set pressure is of the pressure relief device on a tank truck, or perhaps what the MAWP is of the tank on a tank truck? If it matters, this is for a crude oil tank truck, either a semi or a tandem trailer. I have not been able to find it anywhere. Thanks! Pete

 

[KernOily]

OK I found one thus far, a 110 bbl tank used for gasoline/diesel. It has MAWP of 5 psig. I do not know if this type of trailer would be used for hauling crude oil. Still looking.

 

[LittleInch]

It seems to depend on what is planned to be transported. The design pressure needs to be greater than the highest vapour pressure that can be produced at the highest product temperature to avoid vapour release under normal conditions. 5 psig would cover most liquid fuels and crude oil, but as ever each one, especially crude oil is different.

Therefore there is no fixed standard.

It should be noted on the tank nameplate fixed to the tanker body.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[zdas04]

Most of them around here pressurize the tank to empty them (they have a compressor instead of ta pump). To reliably be able to get into the top of a 1000 bbl tank they have a PSV set at 30 psig. The ones with pumps are lower (some are atmospheric).

David Simpson, PE
MuleShoe Engineering

Law is the common force organized to act as an obstacle of injustice Frédéric Bastiat

 

[moltenmetal]

I've seen pictures that confirm that they don't much like vacuum-

There was a paper I had a copy of long ago that had pictures of vacuum-related failures. Damn, I wish I could find that thing! Can't remember which magazine or journal it was from, and it was at least 20 years ago. It had a picture of a tanker truck which basically looked like a string of sausages, crushed by vacuum in-between each set of anti-slosh baffles.

 

[KernOily]

OK I got the answer. The MAWP for crude oil tankers, whether semi or tandem, is 25 to 30 psig depending on the manufacturer. And they are built to DOT 407 (actually MC407AL). So there's a random bit of knowledge to file away in your bag o tricks. Might save you a compressor skid sometime.

Thanks for the replies guys!!! Pete

 

[maddocks]

We use pressurized LPG tankers - designed for 250 Psig. Totally depends on the fluid, the contract and the hauling company.