×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Oil/Gas In rubber hose - Static implications

Oil/Gas In rubber hose - Static implications

Oil/Gas In rubber hose - Static implications

(OP)
Hi Guys, I'm an electrical engineer
Posting this in here, but if it's not the right forum, please point me to another

Issue is, that I'm involved in doing the grounding design at a type of fuel station where trucks (tankers) will be filled with a fuel

I think that the equipotential leads that earth the truck/tanker when its filling have a switch on them so that you can (I guess) control when or not the truck/tanker is floating and when it's grounded

Does anyone have any info on the purpose of that switch or can you shed some light onto the usefulness of it?

Also, if the fuel is diesel, which I believe is combustible but not flammable, then is there any need to worry about static discharge?

Cheers!

RE: Oil/Gas In rubber hose - Static implications

when loading trucks of any kind of material,its not that the truck is grounded, its that the truck is bonded to the equipment it is loading from. This means there is not POTENTIAL charge between the truck and the tanks/pumps et al.

I've seen trucks loading saltwater with some heavy oil and vapours burst into flames because the truck was not bonded to the tanks they were pulling from.

Guess what, diesel is falamble under the right conditions.  Diesel makes a good fire starter for bond fires and in backyard barbies too.

RE: Oil/Gas In rubber hose - Static implications

All the loading/unloading stations I have seen constructed recently have some form of interlock so that loading/unloading cannot commence until the truck is correctly bonded. As an electrical, I guess you know how to do this better than I can.

RE: Oil/Gas In rubber hose - Static implications

We have to connect to ground all trucks prior to load/unload, otherwise the pumps will not start (interlocked).
In our case, all equipment is grounded, therefore the trucks have to be grounded.
In other applications, as dcasto indicated, the truck/tanker has to be bonded to the equipment.
In both cases the goal is the same, cero potential charge.
I am not going to say either is fail safe, because I have seen truckers that "ground" their truck by the front fender while they are unloading from the back. There is no guarantee that there is conectivity throughout the truck.
If you google on why gas stations require you not to get back into your car while loading you'll see what I mean.

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying " Damn that was fun!" - Unknown>>

RE: Oil/Gas In rubber hose - Static implications

(OP)
Yeah, thanks for the help guys.

I found out that the purpose of the switch was so that the initiation of contact (that could result in a spark) would be geographically (located) away from the hazardous area.

That is, if there wasn't a switch in the equipotential lead, then you could spark AT the truck when connecting it up. Better to be doing the spark at a safe distance (the location of the switch).

Cheers

RE: Oil/Gas In rubber hose - Static implications

Check API RP 2003 and NFPA 30 for grounding, bonding, interlocks and static relaxation.  Also review the signals and interlocks at existing bulk plants or product terminals similar to your project.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources