How to Select Materials for Different Service Media? (CF8 vs. CF3M: What's the Difference?)

   In valve procurement, many customers hold a serious misconception: they believe that "as long as it's stainless steel, the corrosion resistance is much the same." In reality, in industrial piping systems, selecting the wrong stainless steel grade shortens the service life of the valve, causes internal leakage, and can trigger chemical reactions — or even become the leading cause of a safety incident.

   Zhejiang Bolaise Valve Co., Ltd. has always stood by one belief: "A contract is more than a transaction of goods — it is a customer's trust in us. And the first step in safeguarding that trust is helping our customers choose the right material, right from the source." Today, we take an in-depth look at the two most fundamental casting materials in the valve industry — CF8 and CF3M — and examine exactly which service conditions and media they are suited for.

CF8 (304 Stainless Steel): The "Standard Choice" for Food-Grade and Mildly Corrosive Service

   CF8 is the cast equivalent of 304 stainless steel, offering good general corrosion resistance and easy clean ability.

   Suitable Media: Clean water, oils, food and beverages, pharmaceutical ingredients, and weak organic acids.

   Service Conditions: An exceptionally wide temperature range — fully capable from cryogenic -196°C up to 425°C.

   Typical Applications: Food processing, brewing, pharmaceutical equipment, and indoor pipelines carrying generally corrosive fluids.

CF3M (316L Stainless Steel): The "Ultimate Corrosion Fighter" for Demanding Service

   CF3M is the cast equivalent of 316L stainless steel. It contains molybdenum and has a lower carbon content than CF8, making it the undisputed leader of the two grades in both corrosion resistance and weld ability.

 Suitable Media: Seawater, acids and alkali, and chlorides.

    Service Conditions: From cryogenic temperatures up to 450°C, and especially well suited to pipelines that require field welding.

     Typical Applications: Offshore platforms, ship seawater piping systems, flue gas desulfurization and denitrification projects, chemical acid and alkali pipelines, and high-purity welded sanitary piping.

     A Reminder from Bolaise Valve: The addition of molybdenum gives CF3M a "protective shield" against chloride pitting; and its lower carbon content than CF8 ensures the valve will not suffer intergranular corrosion after welding. In chemical and marine engineering, CF3M is the true "gold standard" you can rely on.

Why Choose Bolaise Valve? 

   Zhejiang Bolaise Valve Co., Ltd. has always upheld this belief: "A contract is more than a transaction of goods — it is an entrustment to us of pipeline safety and our customer's reputation." We rigorously inspect every batch of raw material castings, and from machining precision to pressure testing, we refuse to compromise at any stage of the process.

   We will never recommend an unsuitable material simply to win an order. Whether it is CF8 or CF3M, Zhejiang Bolaise Valve will safeguard your project with stable manufacturing processes and strict quality inspection.

If you are selecting stainless steel valves for a project but remain unsure about choosing between CF8 and CF3M, please feel free to contact us at any time.