Hydrotest Fluid : Cl content

[yanuarsaja]

Hi,
I read some spec for vessel,for hydrotest purpose max. Chlor is 30 ppm
I think,it will applicable for CS and SS material.
Another reference said for Shell and Tube Heat Exchanger (stainless steel).. Shall have Chlor content 25 ppm.

Question: i think both PV and STHE should have same requirement for hydrotest. Is it because in SS, it can trigger CSCC (chlor stress corrosion cracking)?

How much value of chlor which normaly used for hydrotest based on your experience? And the difficulty to comply it??

Thank you
Yanuar

 

[weldstan]

Chloride limits in hydrotest water are normally defined as 20 ppm or 50 ppm (depending on Customer/Engineer) for austenitic stainless steel pressure retaining equipment.

 

[EdStainless]

At low concentrations NaCl raises the conductivity of water about 2 uSiemens for each ppm of concentrations.
In SS tube testing we often are working with water that is less than 2uS, 1ppm Cl max.
In the field limits of 50uS (20k ohm resistance) are common, this would be roughly 23ppm TDS (or NaCl if that were the only thing in the water).

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P.E. Metallurgy, Plymouth Tube