Corrosion resistant valves – Erreesse

Corrosion resistant valves: Chlorides, wet acid gas and wet sour gas service

Process corrosive fluids are all those containing even minimum concentration of Sulfuric Acid (H2SO4), chlorides, wet acid gas (with Carbon Dioxide, CO2) and wet sour gas (with Hydrogen Sulphide, H2S). Corrosion resistant alloy (CRA) materials, overlays or PTFE lining (Halar coating) on exposed pressure containing & retaining components should be considered to prevent the integrity of the valve and minimize the possibility of failures and leakage. Materials for sour service (Hydrogen Sulphide, H2S) shall be also conform to NACE MR0175 (ISO 15156) or NACE MR0103 if specified for refinery service.

Corrosion is a gradual loss of material by chemical or physical reaction with the process fluid; depending on concentration, temperature and pressure drop the exposed to fluid surfaces can be seriously damaged impairing the performance of the valve, unless the correct valve type and materials are selected. Those services where the process fluid may contain aggressive contaminants or suspended solid particles are typically identified as corrosive & dirty applications. Erreesse valve ranges includes special models suitable for severe abrasive, slurry, scaling, fouling and solidifying services.

The below listed services can exist in combination with other services or applications, including toxic substances like Sodium Hydroxide (NaOH), Chlorines (Cl), flammable liquids (LNG, LPG or NGL condensate) or generic hydrocarbon gas in high pressure, cryogenic or high temperature applications.

 

-Chlorides, wet acid gas and wet sour gas service

Process corrosive fluids are all those containing even minimum concentration of Sulfuric Acid (H2SO4), chlorides, wet acid gas (with Carbon Dioxide, CO2) and wet sour gas (with Hydrogen Sulphide, H2S). Corrosion resistant alloy (CRA) materials, overlays or PTFE lining (Halar coating) on exposed pressure containing & retaining components should be considered to prevent the integrity of the valve and minimize the possibility of failures and leakage.Materials for sour service (Hydrogen Sulphide, H2S) shall be also conform to NACE MR0175 (ISO 15156) or NACE MR0103 if specified for refinery service.

-Abrasive and sandy service

Abrasive service identifies the presence of solid particles (hard granules, powder, rust, slags, sand), occurring during line construction, clearing operations or oil & gas production, that can damage seating surfaces and clog the flow with and excessive operating force with potential seat leakage. Sandy service identifies severe abrasive and erosive conditions with high content of suspended sand; pressure drop in this case can be very high, it is important to prevent damages on seating areas, ball & seats should be protected with tungsten or chrome carbide coating as a minimum; soft seated valves shall not be considered for this service.

-Slurry and fouling service

Slurry service identifies liquid fluids with suspended particles or solids where the solid is the product and the fluid is the means of transportation while fouling service identifies liquids with suspended fine sand or limestone that forms deposits on surfaces. Weld overlays and metal seated construction are not enough to prevent the valve from damages, a special design and a careful selection of materials should be considered instead.

-Solidifying service

Solidifying service identifies a fluid that can change from liquid to solid status, like Phthalic Anhydride (C6H4(CO)2O) or liquid Sulphur (S); metal seated and steam jacketed construction with special consideration to valve design can be a good solution to prevent performance of the selected valve.