46 CFR § 108.443 - Controls and valves.

---
identifier: "/us/cfr/t46/s108.443"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 108.443 - Controls and valves."
title_number: 46
title_name: "Shipping"
section_number: "108.443"
section_name: "Controls and valves."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "I-A"
subchapter_name: "A—MOBILE OFFSHORE DRILLING UNITS"
part_number: "108"
part_name: "DESIGN AND EQUIPMENT"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "43 U.S.C. 1333; 46 U.S.C. 3102, 3306; DHS Delegation No. 00170.1, Revision No. 01.4."
regulatory_source: "CGD 73-251, 43 FR 56808, Dec. 4, 1978, unless otherwise noted."
cfr_part: "108"
---


# 108.443 Controls and valves.

(a) At least one control for operating a CO<sub>2</sub> system must be outside the space or spaces that the system protects and in a location that would be accessible if a fire occurred in any space that the system protects. Control valves must not be located in a protected space unless the CO<sub>2</sub> cylinders are also in the protected space.

(b) A CO<sub>2</sub> system that protects more than one space must have a manifold with a stop valve, the normal position of which is closed, that directs the flow of CO<sub>2</sub> to each protected space.

(c) A CO<sub>2</sub> system that protects only one space must have a stop valve installed between the cylinders and the discharge outlets in the system, except on a system that has a CO<sub>2</sub> supply of 136 kilograms (300 pounds) or less.

(d) At least one of the control stations in a CO<sub>2</sub> system that protects a machinery space must be as near as practicable to one of the main escapes from that space.

(e) All distribution valves and controls must be of an approved type.

(f) Each CO<sub>2</sub> system that has a stop valve must have a remote control that operates only the stop valve and must have a separate remote control for releasing the required amount of CO<sub>2</sub> into the space protected by the system.

(g) Each CO<sub>2</sub> system that does not have a stop valve must be operated by a remote control that releases the required amount of CO<sub>2</sub> into the space protected by the system.

(h) Remote controls to each space must be in an enclosure.

(i) Each system must have a manual control at its cylinders for releasing CO<sub>2</sub> from the cylinders, except that if the system has pilot cylinders, a manual control is not required for other than pilot cylinders.

(j) If gas pressure is used to release CO<sub>2</sub> from a system having more than 2 cylinders, the system must have at least 2 pilot cylinders to release the CO<sub>2</sub> from the remaining cylinders.

(k) If the entrance to a space containing the CO<sub>2</sub> supply or controls of a CO<sub>2</sub> system has a lock, the space must have a key to the lock in a break-glass type box that is next to and visible from the entrance.