What working conditions require a fully welded stainless steel filter element?

1. Typical scenarios where stainless steel filter elements are required

1. High temperature or high pressure environment

Reason: Stainless steel (such as 316L) is resistant to high temperature (≤500℃) and high pressure (≥10MPa), and is suitable for the following processes:

Steam filtration, high temperature gas purification.

Chemical reactor feed filtration (such as strong acid/alkali media).

Alternative: If the temperature is <150℃, polytetrafluoroethylene (PTFE) filter elements can be considered.

2. Strong corrosive media

Applicable conditions:

Handling concentrated sulfuric acid, hydrofluoric acid, etc. (stainless steel needs to choose corrosion-resistant models, such as Hastelloy).

Filtration of liquids without resin but containing oxidants (such as sodium hypochlorite).

Exception: If the medium is weak acid/alkali (such as pH 4-9), PP (polypropylene) filter elements can be used.

3. High mechanical strength requirements

Scenario:

Filtration of slurry containing solid particles (such as mining, ceramic glaze).

Systems with frequent backwashing or high-pressure backwashing.

Advantages of stainless steel: impact resistance, not easy to deform, lifespan up to 5-10 years.

4. Sanitary requirements

Industry: food, pharmaceutical (such as resin-free syrup, injection filtration).

Characteristics of stainless steel: surface finish Ra≤0.8μm, easy to clean and sterilize (CIP/SIP).

2. Scenarios where stainless steel filter elements are not required

1. Non-corrosive liquids at normal temperature and pressure

Recommended filter elements:

PP melt-blown filter element: low cost, disposable (such as pretreatment filtration).

Nylon filter membrane: precision 0.1-10μm, suitable for clarification filtration.

2. Containing organic solvents but no resin

Choice: PTFE filter element: solvent resistant (such as acetone, DMF), chemical compatibility is better than stainless steel.

3. Disposable or low-cost requirements

Alternatives:

Cellulose filter paper: suitable for small-scale laboratory filtration (such as resin-free extract).

Ceramic filter element: high temperature resistant but brittle, suitable for fixed installation.