On a 90 degree or 45 degree pipe bend, if shackle rods are used, they should be placed in _________ and be on the _________ of the bend.

• A. Concrete blocks, inside
• B. Wood blocks, outside
• C. Concrete blocks, outside
• D. Steel blocks, inside

Answer: (A)

The key idea is to provide a solid, fixed anchor for the bend so it won’t shift during installation, backfilling, or under pressure. When shackle rods are used on a 90-degree or 45-degree bend, placing the anchor in concrete blocks on the inside radius gives a rigid, immovable support right at the part of the bend that needs to stay aligned. Concrete blocks are durable and can be poured to fit the bend, giving a stable backing that won’t deform, unlike wood, which can rot or compress, or nonstandard steel blocks. Placing an anchor on the outside of the bend could create leverage that promotes movement or misalignment, so the preferred practice is concrete blocks inside the bend.