ISO 17579:2025

International
Standard
ISO 17579
First edition
Ships and marine technology —
2025-03
Design and testing requirements of
pneumatic quick-closing valves
Navires et technologie maritime — Exigences de conception et
d'essai des soupapes pneumatiques à fermeture rapide
Reference number
© ISO 2025
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ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Pressure and temperature . 3
5 Structure and design . 3
5.1 General .3
5.1.1 Structure .3
5.1.2 Materials .3
5.2 Design and materials of the body .4
5.2.1 Design . .4
5.2.2 Materials .4
5.2.3 Manufacturing .4
5.3 Design and materials of the bonnet .4
5.3.1 Design .4
5.3.2 Materials .4
5.4 Design and materials of the disc .4
5.4.1 Design .4
5.4.2 Materials .4
5.5 Design and materials of the stem .5
5.5.1 Design .5
5.5.2 Materials .5
5.6 Stem sealing .5
5.7 Design and materials of the spring.5
5.7.1 Design .5
5.7.2 Materials .5
5.8 Design and materials of the pneumatic components .5
5.8.1 Design . .5
5.8.2 Materials .5
5.9 Design and materials of the seat . .6
5.9.1 Design . .6
5.9.2 Bore materials .6
5.10 Design and materials of the connection .6
5.10.1 Design .6
5.10.2 Materials .6
5.11 Requirements of pneumatic components and hand wheel .6
5.12 Surface treatment .6
6 Test and inspection . 6
6.1 General .6
6.2 Material test .6
6.3 Non-destructive testing (NDT) . .7
6.3.1 General .7
6.3.2 Dye penetrant testing (PT) .7
6.3.3 Retest .7
6.3.4 Submission of inspection results .7
6.4 Dimension check .7
6.5 Visual inspection .7
6.6 Operating tests .7
6.7 Pressure tests .8
6.7.1 General .8
6.7.2 Pressure tests in ambient temperature .8
6.7.3 Test procedures and methods .8

iii
6.8 Fire-resistance test .8
7 Marking . . 8
Annex A (informative) Examples of PQCV construction . 10
Bibliography .12

iv
Foreword
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This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology, Subcommittee
SC 3, Piping and machinery.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
Introduction
Marine pneumatic quick-closing valves are extremely important for the prevention of fires caused by
flammable liquids and the overall safety programme onboard ships. According to SOLAS Chapter II-2
[16]
Regulation 4, in the event of a fire, the following must be fitted with a cock or valve directly on the tank,
which can be closed from a safe position outside the space concerned:
a) oil fuel pipes, which, if damaged, would allow oil to escape from a storage;
b) settling or daily service tank having a capacity of 500 l and above, situated above the double bottom.
In older ships, the valve would normally be closed manually through a long mechanical connection from the
valve to the position outside the machinery space. In modern ships, this valve is usually a pneumatic quick-
closing valve (PQCV), which uses compressed air and spring tension to rapidly close off the fuel or oil flow
in the event of a leak downstream of the tank. The PQCV is operated by a pneumatic quick-closing control
devices, the specifications of which are defined by ISO 24225.
Proper operation of pneumatic quick-closing valves is one of the most important items to be checked during
port state supervision ship inspections. If the quick-closing valve operation fails, the port state will likely
require the problem to be corrected before the ship can proceed. This can result in detention of the ship,
with adverse effects on the ship’s schedule. Therefore, it is important to develop standards specifying the
design and tests for pneumatic quick-closing valves to ensure quality and performance. In addition, since
the PQCV is not used on an everyday basis, but is expected to perform as designed in an emergency, proper
operation should be verified regularly and periodic maintenance completed.

vi
International Standard ISO 17579:2025(en)
Ships and marine technology — Design and testing
requirements of pneumatic quick-closing valves
1 Scope
This document specifies requirements for the design and tests of pneumatic driven quick-closing valves,
used in ship fuel and lubricating oil systems to stop the fluid flow in the event of a leak. This document is
applicable to valves of nominal diameter (DN): 15, 20, 25, 32, 40, 50, 65, 80, 100, 125, 150, 200, 250, and 300,
corresponding to nominal pipe sizes (NPS): 1/2, 3/4, 1, 1 1/4, 1 1/2, 2, 2 1/2, 3, 4, 5, 6, 8, 10, and 12.
NOTE This document is mainly intended for use by producers. Onboard ship inspection and maintenance after
the delivery and installation of the valve can help ensure continued proper performance.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 4987, Steel and iron castings — Liquid penetrant testing
ISO 5208, Industrial valves — Pressure testing of metallic valves
ISO 5752, Metal valves for use in flanged pipe systems — Face-to-face and centre-to-face dimensions
ISO 7005-1, Pipe flanges — Part 1: Steel flanges for industrial a
...