Jump to content



Featured Articles

Check out the latest featured articles.

File Library

Check out the latest downloads available in the File Library.

New Article

Product Viscosity vs. Shear

Featured File

Vertical Tank Selection

New Blog Entry

Low Flow in Pipes- posted in Ankur's blog

2

Thermal Expansion Safety Relief Valve


5 replies to this topic
Share this topic:
| More

#1 mido

mido

    Junior Member

  • Members
  • 26 posts

Posted 30 November 2018 - 03:14 AM

we have many cases in our plants of installation indirect heaters in trunk lines and at oil processing plants inlet. the supplier of indirect heaters sometimes supplied it with thermal expansion safety relief . i want to know when this safety relief is mandatory to install and when it is not mandatory because some other suppliers supplied indirect heaters without this PSV. and what the reference for install or not install that PSV?

thanks very much



#2 fallah

fallah

    Gold Member

  • ChE Plus Subscriber
  • 4,622 posts

Posted 30 November 2018 - 03:31 AM

Mido:


 

In general when the fluid being heated is blocked in and the heating fluid is still flowing...



#3 Chemitofreak

Chemitofreak

    Gold Member

  • Members
  • 88 posts

Posted 30 November 2018 - 03:41 AM

Liquid thermal expansion over pressure can occur, when a system that contains a liquid is blocked in and the heat is gained from the environment (solar) or from the process. This causes the liquid to heat up and expand. If the liquid is confined, this expansion can result in over pressure.
 
One has to take into consideration the amount of liquid that can be trapped in between two valves for specifying the thermal relief valve.

Edited by Chemitofreak, 30 November 2018 - 03:45 AM.


#4 mido

mido

    Junior Member

  • Members
  • 26 posts

Posted 01 December 2018 - 03:26 AM

Thanks for reply but my concern is about the need of safety relief if if the indirect heater have only manual isolation valves and not have automated shutdowns ...... can we remove this psv and control this hazard by administrative control that (in case of heater isolated to drain it). as this project is upgrade to existing system and to connect PSV to flare is not feasible.  



#5 fallah

fallah

    Gold Member

  • ChE Plus Subscriber
  • 4,622 posts

Posted 01 December 2018 - 05:36 AM

Thanks for reply but my concern is about the need of safety relief if if the indirect heater have only manual isolation valves and not have automated shutdowns ...... can we remove this psv and control this hazard by administrative control that (in case of heater isolated to drain it). as this project is upgrade to existing system and to connect PSV to flare is not feasible.  

 

In general, administrative control cannot be used instead of a PSV for overpressure relief...



#6 asantosa

asantosa

    Brand New Member

  • Members
  • 3 posts

Posted Today, 09:51 AM

Hello, interesting this topic reagrding on the volumne of the fluis that it is blocked; but actually, I´ve never found volume criteria of the fluid  that is trapped? FOoinstance, if the volume is higher than 50 liters, do I hace to install a TRV, no matter the classification of the fluid is ? ( inflamable, or toxic, etc ). This criteria shall be applied in interconnecting lines outside of batttery limit  or tanckage areas, but actually I do not know the volume or pipe lenght to be applied...Does anyone has heard about criteria for this? thanks






Similar Topics