NACE MR 0 175 compliant material for Flow meters 1

[Ali_1983]

Can stainless steel (either S 304 or SS 316) be used as a material for construction for flow meters with NACE MR-01-75/ISO 15156 compliant for custody transfer application ?

The max operating pressure and temperature in the process pipe is as follows, Pressure: 15 barg, Temperature: 34 Deg C max, the design pressure is 47.5 barg. The medium is crude oil.

The H2S content for 4 out of 5 zones is < 1 PPM, only for 1 zone the H2S content is stated as max 70 PPM.

Kindly advise on the material of construction.

 

[Chumpes]

Hi
did you already have a look into the document NACE MR0175/ISO 15156 ?
why don't you use carbon steel ?
what is the water content ? what is the water dew point temperature (°C) ? what is the H2S content into the liquid free water phase (ppmw) ? what is the partial pressure H2S (bar) ? what is the chloride concentration into the liquid free water phase (ppmw)?

knowing the above, you may find information you need directely into the document, please try to start reading part 3 and have a look at table A.2

regards

 

[Ali_1983]

Dear Chumpes,

Thank you for your reply.

Water cut maximum mentioned is 3.1%, chloride concentration not known, dew point temperature of water also not know,

There is one zone with 70 PPM H2S, the other zones have < 1 PPM or 0 H2S content, would carbon steel (CS) be a suitable option ? Pls recommend ?

Can carbon steel be used for zones where the H2S content < 1 PPM ? And say stainless steel grade S 304 be used for zone where H2S content is 70 PPM ?

Pls advise.

 

[EdStainless]

Are you specifying this equipment? I suggest that you study some more.
This is the purchasers responsibility.
I sure wouldn't proceed without knowing the Cl levels.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[Chumpes]

Hi
when flow regimes are established and favorable, in absence of retention zones (low points) where free water can separate and accumulate, I believe the limited watercut (3.1%) would provide limited wetting of metallic surface and then carbon steel (with resistance to sour service if required) may be applicable for pipings at T=34°C. I don't know flowmeter technology that may require stainless steel for this item.

As EdStainless told, unknown chlorides makes it difficult to conclude SS 304L/316L are adapted... chloride concentration is also a key variable for corrosion of stainless steels. I also believe chloride ions have only moderate influence on the corrosion of carbon steel like material.

 

[Chumpes]

Water cut maximum mentioned is 3.1%, chloride concentration not known, dew point temperature of water also not know,

for your information, when liquid water phase exists at equilibrium with other phases, then the water dew point temperature IS the operating temperature ! =))