[Code of Federal Regulations]
[Title 46, Volume 1]
[Revised as of Octobery 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR38.10-20]

[Page 495-496]
 
                           TITLE 46--SHIPPING
 
         CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY
 
PART 38_LIQUEFIED FLAMMABLE GASES--Table of Contents
 
     Subpart 38.10_Piping, Valves, Fittings, and Accessory Equipment
 
Sec. 38.10-20  Liquid level gaging devices--TB/ALL.

    (a) Each tank shall be fitted with a liquid level gaging device of 
approved design to indicate the maximum level to which the tank may be 
filled with liquid:
    (1) Between -20[deg] F. and 130[deg] F. for unrefrigerated service; 
or,
    (2) Within the operating temperature range for tanks operating below 
atmospheric temperature.
    (b) Liquid level gaging devices may be of the following types: 
Rotary tube, slip tube, magnetic, automatic float, or similar types 
approved by the Commandant. Except as otherwise provided in this 
section, fixed tube devices are not acceptable as the primary gaging 
device.
    (c) All gaging devices shall be arranged so that the maximum liquid 
level for product being carried, to which the tank may be filled is 
readily determinable. The maximum gallonage capacity as required by 
Sec. 38.15-1 shall be:
    (1) Marked on the tank system nameplate or gaging device; or,
    (2) Shown in the ullage tables.
    (d) Gaging devices that require bleeding of the product to the 
atmosphere, such as the rotary tube, fixed tube, and slip tube, shall be 
so designed that the bleed valve maximum opening is not larger than a 
No. 54 drill size (0.055-inch diameter), unless provided with an excess 
flow valve.
    (e) For pressure vessel type tanks each automatic float, continuous 
reading tape or similar type gage not mounted directly on the tank or 
dome shall be fitted with a shutoff device located as close to the tank 
as practicable. When an automatic float gaging device, which gages the 
entire height of the tank is used, a fixed tube gage set in the range of 
85 percent to 90 percent of the water capacity of the tank shall be 
provided in addition as a means of checking the accuracy of the

[[Page 496]]

automatic float, gage, or other alternate means acceptable to the 
Commandant may be used.
    (f) A gaging device shall be designed for a pressure at least equal 
to the maximum allowable pressure of the tank on which it is installed.
    (g) Gage glasses of the columnar type are prohibited.
    (h) Flat sight glasses may be used in the design of automatic float 
continuous reading tape gages: Provided, That such glasses shall be made 
of high strength material suitable for the operating temperatures of not 
less than one-half inch in thickness and adequately protected by a metal 
cover.