Vapor Recovery from Truck Loading
Vapor Recovery from Truck Loading
(OP)
Hi guys. Not sure this is the right forum, but.
Question: What is the typical method/strategy used for vapor recovery of vapors displaced during truck loading? The commodity is light crude oil. The trucks will be bottom-loaded. The connection for the vapor line is on the bottom also, if that matters. Thanks in advance!!
Question: What is the typical method/strategy used for vapor recovery of vapors displaced during truck loading? The commodity is light crude oil. The trucks will be bottom-loaded. The connection for the vapor line is on the bottom also, if that matters. Thanks in advance!!





RE: Vapor Recovery from Truck Loading
Best regards, Morten
RE: Vapor Recovery from Truck Loading
Normally you have an internal pipe in each compartment open in the tanker vapor space and continued outside of the compartment(s) to a common API coupling for vapor return next to the API filling couplings on the bottom of tanker. The loading station has a vapor return line piped back to the storage tank. The vent line is interlocked with the filling line, so you cannot start filling unless the vapor return line is connected to the storage tank and the grounding cable is connected to the tanker. This is a standard 'loading arm' station for road tanker filling. The grounding line is also an instrument conductor for the filling rate monitoring, the over-fill protection and net transfer control. The control system is either a complex, SCADA like system or a simple local control panel and batch controller, containing all the standard controls and interlocks. Most of the local controllers are standard, off-shelf purchase items, but require programming and connection to the plant monitoring system. The internet is full bursting with relevant info, everyone wants to sell you components or up to turnkey filling stations.
Cheers,
gr2vessels
RE: Vapor Recovery from Truck Loading
RE: Vapor Recovery from Truck Loading
RE: Vapor Recovery from Truck Loading
The diagrams I have seen thus far all show the vapor space of the truck connected to the vapor space of the unlosding tank, this done to equalize the pressure inside the truck. This won't work if the truck is being loaded from a floating roof tank.
I really need a Truck Loading 101 class or a primer. I have searched everywhere and haven't found anything. Thanks guys!
RE: Vapor Recovery from Truck Loading
If it is non hazardous liquid that doesn't create a hazardous vapour then you could just use air, but floating roof sounds like hydrocarbons to me so air is a complete no no.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Vapor Recovery from Truck Loading
Yeah - Can't use air to equalize the trucks since the commodity is crude oil.
So then what is the typical method for the inert gas to get to the trucks? Do I just furnish a bottle rack with N2/CO2 bottles, some let-down regulators, and piping to connect to the unloading islands? Then the CO2 piping just connects to the vapor line on the truck I assume?
Thanks brother - I owe you a cold one!
RE: Vapor Recovery from Truck Loading
You might want to create a small pressurised (2 to 3 barg) tank to allow the easy movement of large low pressure volumes.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Vapor Recovery from Truck Loading
RE: Vapor Recovery from Truck Loading
In reference to the engine exhaust method, I have not fouind any connections or hardware (e.g. OPW) that would permit this. The truck would have to be set up with an exhaust connection of some type so the driver can connect the tank vapor line to the exhaust line. Also I believe the pressure would have to be regulated osmehow because the backpressure ont he exhaust can't be allowed to exceed some value before the engine starts to run poorly.
RE: Vapor Recovery from Truck Loading
All you need is a correctly sized vent/vacuum relief valve fitted with a flame arrester. Talk to the manufacturers of road tankers fittings, they have the correct type and size of those valves, including the ones used for crude oil transport.
Cheers,
gr2vessels