Fuel Drain Valves

AC 20-119 · FAA

Public domain · FAAAdvisory Circulars

Overview

The Fuel Drain Valves (AC 20-119) is a public-domain FAA advisory circular, republished here as a free chaptered HTML edition with a linked table of contents and the official PDF.

Publisher: FAA
Document: AC 20-119
Pages: 1

Key points

This advisory circular provides an acceptable means of compliance with FAR requirements for positive locking of fuel drain valves.
FAR Sections 23.999(b), 25.999(b), 27.999(b), and 29.999(b) require that each drain valve must have a means for positive locking in the closed position.
The advisory circular addresses whether a spring-loaded valve can be considered a 'positive locking valve.'
Spring-loaded fuel drain valves conforming to MIL-V-25023B or TSO-C76 may be approved if the operator can visually confirm the valve is closed.
Applicants must demonstrate that the valve will not open inadvertently under operating conditions.

Frequently asked questions

What is the purpose of this advisory circular?

The purpose of this advisory circular is to provide guidance on compliance with FAR requirements for fuel drain valves.

What are the FAR requirements for fuel drain valves?

FAR Sections 23.999(b), 25.999(b), 27.999(b), and 29.999(b) require that each drain valve must have a means for positive locking in the closed position.

Can spring-loaded valves be used as positive locking valves?

Yes, spring-loaded fuel drain valves may be considered positive locking valves if they conform to specific standards and the operator can visually confirm they are closed.

What standards must spring-loaded fuel drain valves conform to?

Spring-loaded fuel drain valves must conform to MIL-V-25023B or TSO-C76 or equivalent.

What must applicants demonstrate regarding the valve's operation?

Applicants must show that the valve will not open inadvertently under operating conditions.

Document

Advisory

U.S. Department of Transportation

Circular

Federal Aviation Administration Date: 2/7 /83 AC No: 20-119 Subject: FUEL DRAIN VALVFS Initiated by: AWS-130 Change: 1. PURFCGE: This advisory circular provides an acceptable ireans, but rot the only means, of compliance with the requirements of the Federal Aviation Regulations (FAR) for EX)Sitive locking of fuel drain valves in the closed position.

2. BllCKGroUND. FAR Sections 23.999(b}, 25.999(b), 27.999(b), and 29.999(b) require, in part: "Each drain • must have manual or autcmatic ireans for positive locking in the closed position . • " This requirement refers to the required drain valves. The PJrpose of this advisory circular is to respond to the question as to whether a spring loaded valve in the closed p:>sition could be considered a "positive locking valve."

3. GUIDANCE. Spring loaded fuel drain valves ronforming to MIL-V-25023B or TSO-C76 or equivalent may be approved for those installations \,,l[lere the person cperating the valve can visually confirm that the valve is closed, provided the applicant has sho.vn that the valve will rot open inadvertently ~~e q:,erating oondition, M. c. Beard Director of Airworthiness