# 255.187 Vaults: sealing, venting and ventilation.

**Citation:** 16 NYCRR 255.187  
**Type / status:** regulation / current  
**Agency:** New York State Public Service Commission  
**Effective:** Not stated  
**Published:** Not stated

Transmission and Distribution of Gas. (a) Each underground vault or closed top pit containing either a pressure regulating or reducing station, or a pressure limiting or relieving station, must be sealed, vented or ventilated.

(b) When the internal volume exceeds 200 cubic feet (5.66 cubic meters), each of the following apply:

(1) The vault or pit must be ventilated with two ducts, each having

## Document text

(a) Each underground vault or closed top pit containing either a pressure regulating or reducing station, or a pressure limiting or relieving station, must be sealed, vented or ventilated.

(b) When the internal volume exceeds 200 cubic feet (5.66 cubic meters), each of the following apply:

(1) The vault or pit must be ventilated with two ducts, each having at least the ventilating effect of a pipe four inches (102 millimeters) in diameter.

(2) The ventilation must be enough to minimize the formation of combustible atmosphere in the vault or pit.

(3) The ducts must be high enough above grade to disperse any gas-air mixtures that might be discharged.

(c) When the internal volume is more than 75 cubic feet (2.12 cubic meters) but less than 200 cubic feet (5.66 cubic meters), the following apply:

(1) If the vault or pit is sealed, each opening must have a tight-fitting cover without open holes through which an explosive mixture might be ignited, and there must be a means for testing the internal atmosphere before removing the cover.

(2) If the vault or pit is vented, there must be a means of preventing external sources of ignition from reaching the vault atmosphere.

(3) If the vault or pit is ventilated, subdivision (b) or (d) of this section applies.

(d) If a vault or pit covered by subdivision (c) of this section is ventilated by openings in the covers or gratings and the ratio of the internal volume, in cubic feet, to the effective ventilating area of the cover or grating, in square feet, is less than 20 to 1, no additional ventilation is required.

## Provenance

- Official: Yes
- Source: <https://govt.westlaw.com/nycrr/Document/I505c96ffcd1711dda432a117e6e0f345?viewType=FullText&originationContext=documenttoc&transitionType=CategoryPageItem&contextData=(sc.Default)>
- Source ID: `ny-dps-nycrr`
- SHA-256: `9792186c7d14e52cfcdfdafc0381fe49153c3b615d46d04287573a3f1594344e`
- Retrieved: 2026-08-12T06:20:40.894Z
- Exported: 2026-08-24T15:41:30.259Z
- Document slug: `ny-nycrr-255-187`

### Source metadata

```json
{
  "jurisdiction": "US-NY",
  "title": 16,
  "part": "255",
  "partTitle": "Transmission and Distribution of Gas",
  "scopeKind": "gas-pipeline-safety",
  "tocPath": [
    "Part 255 Transmission and Distribution of Gas",
    "Design of Pipeline Components"
  ],
  "legalScope": "Complete current terminal legal unit exposed by the DPS-designated Title 16 NYCRR pipeline-safety part inventory.",
  "applicabilityCaveat": "Applicability depends on the part and section, Commission jurisdiction, commodity and facility type, intrastate or interstate status, operator and activity, exemptions, waivers, federal preemption, Commission orders, and incorporated law. DPS inspects portions of interstate systems for PHMSA, but PHMSA retains federal enforcement authority. DPS states that all jurisdictional Part 256 gas-holder and Part 257 LPG-plant facilities have been decommissioned even though those regulations remain unrepealed.",
  "incorporationCaveat": "These parts incorporate or rely on federal pipeline regulations, federal and New York statutes, Commission rules and orders, and privately authored technical standards. Part 10 supplies incorporation details. References metadata preserves explicit citations but does not reproduce external material, determine licensing rights, or decide whether a particular incorporation is static or dynamic.",
  "publicationCaveat": "The New York Department of Public Service identifies these eleven Title 16 NYCRR parts as its state pipeline-safety regulations and links to the public DOS/Westlaw NYCRR reading copy. That site labels the online text unofficial and directs users needing evidentiary accuracy to the Official NYCRR maintained by the Department of State Division of Administrative Rules. Each section's 'Current through' date is the most recent official NYCRR supplement covering that section, not a uniform corpus-wide amendment date.",
  "rights": "New York government-edict text is preserved with DPS, Department of State, and publisher attribution. The public reading site's presentation and enhancements, agency marks, forms, annotations, and incorporated federal or privately authored standards require separate rights review; this connector does not claim rights in those materials.",
  "rightsReviewRequired": true,
  "currentThrough": "2024-05-31",
  "historyEvents": "No event is emitted because the section reading copy does not supply an explicit adoption, filing, or effective-date history.",
  "publisherCitation": "16 CRR-NY 255.187",
  "identityAnomaly": null,
  "references": [],
  "region": "NY"
}
```