[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: 46CFR39.20-7]

[Page 504-505]
 
                           TITLE 46--SHIPPING
 
         CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY
 
PART 39_VAPOR CONTROL SYSTEMS--Table of Contents
 
                   Subpart 39.20_Design and Equipment
 
Sec. 39.20-7  Tankship liquid overfill protection--T/ALL.

    (a) Each cargo tank of a tankship must be equipped with an 
intrinsically safe high level alarm and a tank overfill alarm.
    (b) The high level alarm and tank overfill alarm required by 
paragraph (a) of this section, if installed after July 23, 1990 must:
    (1) Be independent of each other;

[[Page 505]]

    (2) Alarm in the event of loss of power to the alarm system or 
failure of electrical circuitry to the tank level sensor; and
    (3) Be able to be checked at the tank for proper operation prior to 
each transfer or contain an electronic self-testing feature which 
monitors the condition of the alarm circuitry and sensor.
    (c) The high level alarm required by paragraph (a) of this section 
must:
    (1) Alarm before the tank overfill alarm, but no lower than 95 
percent of tank capacity;
    (2) Be identified with the legend ``High Level Alarm'' in black 
letters at least 50 millimeters (2 inches) high on a white background; 
and
    (3) Have audible and visible alarm indications that can be seen and 
heard on the vessel where cargo transfer is controlled.
    (d) The tank overfill alarm required by paragraph (a) of this 
section must:
    (1) Be independent of the cargo gauging system;
    (2) Have audible and visible alarm indications that can be seen and 
heard on the vessel where cargo transfer is controlled and in the cargo 
deck area;
    (3) Be identified with the legend ``TANK OVERFILL ALARM'' in black 
letters at least 50 millimeters (2 inches) high on a white background; 
and
    (4) Alarm early enough to allow the person in charge of transfer 
operations to stop the transfer operation before the cargo tank 
overflows.
    (e) If a spill valve is installed on a cargo tank fitted with a 
vapor collection system, it must meet the requirements of Sec. 39.20-
9(c) of this part.
    (f) If a rupture disk is installed on a cargo tank fitted with a 
vapor collection system, it must meet the requirements of Sec. 39.20-
9(d) of this part.