One possibility might be BS 1710 - Identification of pipelines and services.

Scope is:

This British Standard specifies the colours for the
identification of pipes conveying fluids in above ground
installations and on board ships on a generic basis. It also
includes ducts for ventilation and conduits used for
carrying electrical services.
The following three methods of identification are included:
(a) basic identification colours only;
(b) basic identification colours and code indications;
(c) basic identification colours used in conjunction
with the user's particular colour coding scheme.


A.

here is what I have seen most often

Red - main fire fighting. (Usually raw water)
Blue - potable water.
Green - raw water for engine cooling or heads.
Yellow - Fuel.
Brown - sewage.

AS1345 (Australian Standard) is another standard for pipe marking. This varies from what Pauljohn states. The best approach would be specify to the country where the vessel will operate most often or where it is to be registered. AND ensure there is a chart correlating colour and contents available on board the vessel.

Mark Hutton

Mark - you are right. If this is a commercial vessel then there might be local regs or codes that have to be adhered to.

If its a private vessel (I got the impression it was) then you are free to make up your own. The colours I mentioned are simply the most common I can remember seeing. Many Brits like to use Black for sewage (Blackwater tank) and Brown for diesel fuel. I have seen some that use stripes to distinguish feed pipes and overboard pipes. Personally I would keep it simple on a private yacht, once you have a few marked it is not difficult to work the others out.

It might be better to make up your own, if you are not bound by any regs, so you would remember it in an emergency situation.

Paul
For a private vessel use of standard colours and a chart to relate colour to contents would be more applicable. As a private vessel it is more likely that there will be various sub contractors and possibly a range of crew working her. Regardless of the colour selections teh key or code to relate colour to contents is paramount.

Mark Hutton

I was looking for some standard for a commercial veesel.
A few years back we all went IMO standards for shipping
at that point it seems that every company came up with its
own c/code within it's Safety Management System (SMS).
But there still seems to be no stardard. The British seem
set a good part of IMO, but I still can't find any color
code set in the IMO rules. This bugs me! When trying to train new poeple we send them off to other companys. They
see a new code, which could lead to some very bad mistakes.
I believe the USCG/Navy still use the basic sys that Paul
mentioned and that sys did work anybody that was taught it
knew it for life.

http://www.technische-klebeschilder.de/schiffsrohrkennzeichen-iso.htm

Google ISO 14726 and get more info also.

I am in Canada and the inspectors were quite reluctant to let us go once until we painted the fuel tank vents the proper color (Brown)
So it does matter

http://www.imo.org/includes/blastDataOnly.asp/data_id%3D8819/834.pdf

This link is interesting for engine rooms also

Check Classification society rules
(DNV; LR etc)

I'd not looked at ISO 14726 before.

Reading it alongside BS 1710 is a slightly disturbing experience.  There are enough areas where the two standards coincide for the unwary to be led astray, and one or two areas (for instance, whether a pipe marked just in blue might be expected to carry fresh water or compressed air) where being astray could be troublesome.

This adds weight to the call from several contributors here to have a chart available onboard outlining the system in use.

Writing it in words on the outside of the pipe always helps too.

A.

zeusfaber,
I have had similar concerns in relation to the different colour codes from different countries. I have not looked at ISO 14726, however had had experience with AS/BS/Petrochem pipe colour coding, and match your experience. Some disturbing different colour/content combinations! When working in different industries and different companies they have all use different colour schemes.

The key to not getting caught out is to ask what colour standard they are working to. As I have stated and reinforced always have a colour/contents chart to decode the system.

Writing the contents name on the pipe is also a good practice, but what language, not everyone speaks English! An excellent example here is; Bahasa Indonesian for “water” is “air”! (Pronounced aieer) Learnt that one as design manager on Pharma plant in Indonesia! Real confusing! In wider industrial sites a line will have an identifier (serial number) and initials for contents e.g. PW for Purified Water lines.

Mark Hutton

Quote (HEC):

Bahasa Indonesian for “water” is “air”.

Sweet.  You couldn't make something like that up.

A.

Paul John, I have most seen what you have described, except for these exceptions

white = steam
yellow = lube oil
orange = diesel oil
black = heavy fuel