🔍 Key Concepts

• Differences between insulating vs binding refractory products • Typical use of castable vs cement/mortar materials in machinery lagging (piping, turbines, non‑boiler equipment) • Which materials are designed to provide thermal insulation rather than just hold bricks or blocks in place

💭 Think About

• For each option, ask: is this mainly used to insulate surfaces or to bond/line refractory bricks in boilers and furnaces? • Think about which material would most likely be applied over machinery or piping similarly to lagging or other insulation systems, not to build a furnace wall. • Which of these products is specifically marketed/known as an insulation material rather than a structural or bonding refractory?

✅ Before You Answer

• Identify which choices are primarily bonding agents (mortar, cements) vs true insulation products. • Confirm which material can be cast or applied in place to form an insulating layer on machinery surfaces outside the boiler setting. • Eliminate any choices whose main function is holding firebrick or refractory shapes together rather than providing standalone insulation.