# Expansion or contraction.

**Citation:** 49 CFR 193.2135  
**Type / status:** regulation / historical  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 1999-10-01  
**Published:** Not stated

Each operator shall consider the amount of contraction and expansion of each component during operating and environmental thermal cycling and shall:

(a) Provide components that operate without detrimental stress or restriction of movement, within each component and between components, caused by con

## Document text

Each operator shall consider the amount of contraction and expansion of each component during operating and environmental thermal cycling and shall:

(a) Provide components that operate without detrimental stress or restriction of movement, within each component and between components, caused by contraction and expansion; and

(b) Prevent ice buildup from detrimentally restricting the movement of components caused by contraction and expansion.

## Provenance

- Official: Yes
- Source: <https://www.govinfo.gov/app/details/CFR-1999-title49-vol3/CFR-1999-title49-vol3-sec193-2135>
- Source ID: `govinfo-cfr`
- SHA-256: `be9817cbcf638343024a22d4a2959968b2febb9fe402cfa60270d17be170fdad`
- Retrieved: 2026-08-12T01:41:23.231Z
- Exported: 2026-08-23T09:29:07.177Z
- Document slug: `49-cfr-193-2135`

### Source metadata

```json
{
  "part": "193",
  "section": "193.2135",
  "subpart": "Subpart C—Design",
  "annualEdition": 1999,
  "revisedAsOf": "1999-10-01",
  "govInfoPackage": "CFR-1999-title49-vol3",
  "legalStatus": "official-annual-cfr-edition",
  "effectiveDateNote": null,
  "historicalAnchor": true,
  "historicalAnchorNote": "The section appears in an official annual CFR edition but is absent from the connected current eCFR corpus.",
  "jurisdiction": "US"
}
```