---
kind: "section"
citation: "30 C.F.R. § 75.1904"
title: "30"
number: "75.1904"
heading: "Underground diesel fuel tanks and safety cans."
url: "https://uscodex.org/cfr/30/75.1904"
---

# §75.1904. Underground diesel fuel tanks and safety cans.

- (a) **Diesel fuel tanks used underground shall—**
  - (1) Have steel walls of a minimum 3/16-inch thickness, or walls made of other metal of a thickness that provides equivalent strength;
  - (2) Be protected from corrosion;
  - (3) Be of seamless construction or have liquid tight welded seams;
  - (4) Not leak; and
  - (5) For stationary tanks in permanent underground diesel fuel storage facilities, be placed on supports constructed of noncombustible material so that the tanks are at least 12 inches above the floor.
- (b) Underground diesel fuel tanks must be provided with—
  - (1) Devices for emergency venting designed to open at a pressure not to exceed 2.5 psi according to the following—
    - (i) Tanks with a capacity greater than 500 gallons must have an emergency venting device whose area is equivalent to a pipe with a nominal inside diameter of 5 inches or greater; and
    - (ii) Tanks with a capacity of 500 gallons or less must have an emergency venting device whose area is equivalent to a pipe with a nominal inside diameter of 4 inches or greater.
  - (2) Tethered or self-closing caps for stationary tanks in permanent underground diesel fuel storage facilities and self-closing caps for diesel fuel tanks on diesel fuel transportation units;
  - (3) Vents to permit the free discharge of liquid, at least as large as the fill or withdrawal connection, whichever is larger, but not less than 1 1/4 inch nominal inside diameter;
  - (4) **Liquid tight connections for all tank openings that are—**
    - (i) Identified by conspicuous markings that specify the function; and
    - (ii) **Closed when not in use.**
  - (5) Vent pipes that drain toward the tank without sagging and are higher than the fill pipe opening;
  - (6) Shutoff valves located as close as practicable to the tank shell on each connection through which liquid can normally flow; and
  - (7) **An automatic closing, heat-actuated valve on each withdrawal connection below the liquid level.**
- (c) When tanks are provided with openings for manual gauging, liquid tight, tethered or self-closing caps or covers must be provided and must be kept closed when not open for gauging.
- (d) Surfaces of the tank and its associated components must be protected against damage by collision.
- (e) Before being placed in service, tanks and their associated components must be tested for leakage at a pressure equal to the working pressure, except tanks and components connected directly to piping systems, which must be properly designed for the application.
- (f) Safety cans must be:
  - (1) Limited to a nominal capacity of 5 gallons or less;
  - (2) Equipped with a flexible or rigid tubular nozzle attached to a valved spout;
  - (3) Provided with a vent valve designed to open and close simultaneously and automatically with the opening and closing of the pouring valve; and
  - (4) Designed so that they will safely relieve internal pressure when exposed to fire.

## Notes

### Source

Source: 61 FR 55527, Oct. 25, 1996, unless otherwise noted.

### Authority

Authority: 30 U.S.C. 811, 813(h), 957.

### Source

Source: 35 FR 17890, Nov. 20, 1970, unless otherwise noted.