Mobile Toilet Material Selection Standards and Requirements

The selection of materials for mobile toilets should be based on the corrosion level of the usage scenario, with priority given to materials that meet the QB/T 2656 - 2004 standard. The core requirements are as follows:

I. Material Types and Applicable Corrosion Levels

1. 304 Stainless Steel: Suitable for environments with medium to high corrosion levels (such as coastal areas and chemical industrial zones). It has an acid-base resistance range of pH 4 - 10, is highly resistant to high humidity, and does not rust easily, with an outdoor service life of over 20 years. After passing salt spray tests (48 hours of neutral salt spray without rusting) and acid-base immersion tests (immersion in pH 4 acidic solution and pH 10 alkaline solution for 24 hours each without corrosion marks), this material can meet the needs of long-term exposure to corrosive environments.
2. Metal Embossed Panels: Suitable for environments with mild corrosion levels (such as inland cities and dry areas). It has an acid-base resistance range of pH 5 - 9, and its outer anti-corrosion coating enhances moisture resistance, with a weather resistance life of about 15 years. It needs to pass salt spray tests (48 hours without rusting) and acid-base immersion tests (same as above), but long-term high humidity or strong acid-base environments may accelerate coating aging.
3. Fiberglass Reinforced Plastic (FRP): Suitable for environments with medium corrosion levels (such as humid or rainy areas). It has the widest acid-base resistance range (pH 3 - 11), is completely waterproof, and has excellent moisture resistance, with an outdoor service life of about 12 years. It needs to pass salt spray tests and acid-base immersion tests, but extreme temperature differences or long-term exposure to ultraviolet rays may affect material stability.

II. Core Testing Standards and Methods

1. Salt Spray Test: Simulates coastal high-salt-spray environments by placing material samples in a salt spray test chamber for at least 48 hours of neutral salt spray exposure to observe whether rusting occurs on the surface. The pass criterion is no visible rust spots or corrosion products.
2. Acid-Base Immersion Test: Samples are immersed in a pH 4 acidic solution and a pH 10 alkaline solution for 24 hours each to check for corrosion marks, discoloration, or peeling on the surface. The pass criterion is no obvious signs of corrosion.
3. Special Environment Tests: For extreme usage scenarios (such as high-altitude or extremely cold areas), additional ultraviolet aging tests (simulating long-term ultraviolet exposure) and freeze-thaw cycle tests (simulating drastic temperature changes) can be conducted to verify the durability of materials under combined stresses.

III. Key Points for Material Selection Decision-Making

1. Select the appropriate material based on the corrosion level of the usage scenario (mild, medium, or severe) to avoid over-design or insufficient performance.
2. Give priority to materials that have passed the QB/T 2656 - 2004 standard test to ensure that basic corrosion resistance performance meets the requirements.
3. For special environments, additional considerations should be given to the material's resistance to ultraviolet rays and temperature differences. If necessary, choose customized anti-corrosion treatment solutions.