7 replies to this topic

[dhns]

Hai all,

Anybody can expline difference between ,

" Normal temperature and pressure
Standard temereture and pressure
Atmospheric temperature and Pressure
Absolute temperatuer mand pressure "

and Relation between them.,all this thinks for gases , liquids and mixed phase

Regards.,
Dhns,
dhnsekaran@gmail.com

[pleckner]

1. You posted this in the wrong forum as these questions have nothing to do with Relief Devices. Please repost this question in either the "Industrial Professionals" or the "Student" forums, whichever applies.

And this leads me to the following:

2. Please provide your background so that we may better help you understand.

[joerd]

Read http://en.wikipedia....ard_Temperature and come back with any questions the wikipedia can't answer for you.

[Padmakar Katre]

Dear,
This is quite basic question,These are the reference conditions ,

1.NTP-Normal Temp and Pressure - 0 C and 1 atm

2.STP- Standard Temp and Pressure- 20 C and 1 atm (Somewhere it is 16 C and 1 atm)

3.Atmospheric Temp and Pressure- Ambient Conditions which we call as Metrological data (Specific to the locations/sites)

4.Absolute Temperature and Pressure- Absolute temperature is say in degree Kelvin which is K=273.01+degree C and Abs Pressure=Guage+1 i.e. 1atmg=1+1=2 atm (Abs)

Now you tell us how to relate them.Point No 2 which is defined by IUPAC but not universally accepted so tempearture value varies.

Here is onle link where you clear your confusions,

http://en.wikipedia....re_and_pressure

[dhns]

Dear,
i have little bit controduction with your concept.what i have got..in this link http://en.wikipedia....re_and_pressure
i have seeing some different condition for STP..kindly clarify

[pleckner]

A lot of this has to do with the industry you are talking about or in acedameia.

In the (crygoenic) gas industry, NTP is usually defined at 70 degrees F and 14.696 psia (21.1 degrees C and 1 atm). STP in aceademia is usually defined at 32 degrees F and 14.696 psia (0 degrees C and 1 atm). But STP in the typical chemical, gas and oil industries is defined at 60 degrees F and 14.696 psia (15.56 degrees C and 1 atm). And as shown in Wikipedia, some in the oil and gas industry has changed the pressure reference to 14.73 psia.

The bottom line is to never say NTP, STP or whatever WITHOUT GIVING THE BASIS!!!

[Art Montemayor]

Mahesh:

Please don "high jack" some else's thread for your own convenience. Start another thread on the subject matter that you are seeking.

Additionally, pay attention to what Phil Leckner clearly (& boldly) stated:

Always state the temperature and pressure basis for the "Standard" conditions you are refering to.

You haven't done that.