Ceramic Drainage and Chemical Stoneware – Glazing Choice For sanitary pipes and chemical stoneware articles used in sewers, effluent lines, and acid-bearing services, which glazing treatment is most appropriate to obtain a dense, smooth, and durable surface?

Introduction:
This question checks practical knowledge of glazing used for stoneware sanitary pipes and chemical stoneware, where durability, smoothness, and chemical tolerance are needed to reduce abrasion, abrasion driven head losses, and fouling.

Given Data / Assumptions:

• Product: vitrified stoneware pipes and chemical stoneware fittings.
• Service: sanitary sewage, industrial effluents, and chemically aggressive liquids.
• Objective: select a glazing that forms a strong, smooth, and durable skin.

Concept / Approach:

During firing, common practice for stoneware pipes is salt glazing. Common salt reacts with silica at high temperature to form a thin, glassy sodium alumino-silicate film that is adherent, hard, and smooth, improving resistance to abrasion and many chemicals.

Step-by-Step Solution:

Verification / Alternative check:

Standards and catalogs for vitrified stoneware sewer pipes describe salt-glazed internal and external surfaces, confirming long service in harsh drainage conditions.

Why Other Options Are Wrong:

Lead glazing: not preferred for sanitary effluent lines and chemical stoneware due to toxicity and chemical limitations. Opaque or tin glazes are decorative and not the industry norm for sewer stoneware. None of these: incorrect because salt glazing is correct.

Common Pitfalls:

Assuming any glossy glaze is suitable; ignoring process integrated salt glazing used specifically for stoneware pipe manufacture.

Final Answer:

Salt glazing for stoneware pipes