×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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!

*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

delievery truck pump pressure

delievery truck pump pressure

delievery truck pump pressure

(OP)
I have an old 600 gallon liquid nitrogen dewar.  I'm worried that it is possible for the pump on the truck that fills it to over pressurize the vessel.  Its MAWP is 250 psig.  BOC has the contract for filling our dewars (tanks), however I have not been able to get a pump curve for one of their trucks from them.  They tell me not to worry because the relief valves/rupture discs will protect the vessel.  I disagree because the relief devices were sized for fire, not for truck fill rate.  A few people had told me that the truck pumps can deliver 200 GPM LN2 at 350 psig?  Does anyone have an idea of what these delvery trucks can actually deliver?

RE: delievery truck pump pressure

I wouldn't worry too much.  The standard MAWP for a tank that size is ~220 psig and BOC is filling tanks like that all day long.  Most off-loading pumps are good for about 100 psig above the pressure of the tanker, so maybe 120-150 total.  Just make sure that you have the Trycock open when filling to make sure the tank isn't overfilled, or then you might have a problem with pressure.

RE: delievery truck pump pressure

It is true that Pressure relief Valves/ rupture disc in the container would handle the pressure rse if abnormal and moreover BOC handles these kinda jobs in Tons and there is no need to worry!!! Whenever a cryo vesses or in your case, a dewar is designed the relief valves are designed to operate at a pressure less by 30% of your MAWP. A rupture disc would operate/ break away at 15% of your MAWP and they will be able to handle all the pressure rise here. I ve been working with Cryo vessels for a long time and had a great deal about it in UG courses too.

Hope this solves!!!

RE: delievery truck pump pressure

You are wise to notice this could be a problem.  Small tanks fill quickly and some even at the rates you described (200 GPM and 350 psi).  Most of the trucks are lower than that but the hydraulic units can achieve these numbers.  The fact that the vessel is a 250 psi unit helps.  If this were a less than 150 psi unit Air Products would not fill it without a fill line closure device or an engineered orifice.  This came from the death of a delivery driver when a vessel exploded from being overfilled, and the relief devices could not handle the volume that the truck was delivering.  I have information on the incident and the fill line closure device (FLCD) if you are interested in another level of protection.  

Close attention to the pressure should keep you and others safe even with the system you have..

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! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close