2 replies to this topic

[daniwibowo8]

Dear Sir/Madam,

 

We have heatless air dryer which already do a change over dessicant few weeks ago.

As per ANSI/ISA-7.0.01-1996 point 5.1 that :

a. the pressure dew point (PDP) shall not exceeding 4 deg C at line pressure.

b. PDP as measured at the dryer shall be least 10 deg C below the minimum temperature which any parts of the instrument air exposed.

 

Actual Data :

Dew point : -18 deg C (atm dew point)

Pressure outlet air dryer : 6.6 kg/cm2 g.

our lowest ambient temperature for 17 years is 18 deg C

 

Design Data :

Dew point : -20 deg C (atm dew point)

Pressure outlet air dryer : 8.5 kg/cm2 g.

 

I am trying to calculate the PDP using dew point calculator and got PDP design is 6.4 and PDP actual is 6.0 deg C.

 

Is it allowable to use that instrument air quality?

 

Thank you

Dani

[breizh]

Hi Dani ,

Let you consider the document attached . Better to convert your data in ppm water to assess the quality of the instrument air .

 

Hope this helps

Breizh

[daniwibowo8]

Good day

 

Thank you breizh

 

regards, dani