Copper plumbing in old trailer

Hello folks:
I inspected a 1964 trailer yesterday that had copper water distribution plumbing that looks like oil lines. I’ve never seen anything like this before. Was this a common old trailer practice or a home owner job? I’m guessing home owner job, but maybe not? Thanks.

Welcome to the forum.

Got any better photos? what about the copper water lines causes you concern?

I am not very seasoned at this, so I just honestly don’t know, but it seems to me that this is gas line and not plumbing line. It is approx 3/8-1/2 piping and is bendable. I am just curious if this is just some sort of old trailer plumbing or if indeed is oil line material being used as plumbing?

And if it is brass and copper and is working, does it matter?

Those are compression fittings, and could be either water or oil, depending on where they are going.
Nothing wrong with them in a 1965 Manufactured home.

Should be soft type L copper. It comes in different sizes and is allowed given proper connections are made. Those are flare, not compression fittings. Flare is a better joint and is a lot less likely to leak.

Ok great. Thank you very much. Learnt something new!

Why should it be type L and not M or K? Just curious.

You already know (I hope), but I will confirm it once you cite sources for my request from yesterday :slight_smile:

My bad Simon, that is what I meant.

It looks like it’s under the sink possibly in the cabinet, the give away is the hose with the weight. Since it’s on the left side it looks like the pipe that goes up feeds the faucet and the portion that goes left possibly feeds a dishwasher.

I saw that all the time in the vintage cabin/home.

P.S. Welcome to the forum. :smile:

It looks like these are approx. 1/4" copper water supply lines with flare nuts so they would be flare fittings. Flare fittings make very secure mechanical connections which is why they are typically used for oil heating lines, gas line connections for natural gas and propane (LP), etc. Not that common to see flare fittings on a standard residential job but in a trailer where non standard components are the standard this would not be unexpected. They may have been replaced from original. Note that these copper lines are approx. 1/4" so you would expect the functional water flow to be reduced if they are supplying water. 1/2" nominal is the standard size for supply at a minimum so check the flow at all water supply outlets.

Type L copper has blue labeling on it (if there is labeling) and this was the standard thickness back in the day for water supply piping. Very thick wall, costly, etc. They relaxed the plumbing code many years ago and allowed the use of Type M copper (Red labeling) for domestic water supply and also for heating pipe. M copper has a much thinner wall than L. Because it costs less home builders were much happier with the cost reduction of building a new house. M copper has held up well over the years unless you are in an area where the water is very corrosive and “aggressive” and causes premature pinholes and leaks from the water quality itself. K copper is labeled with green lettering, and is commonly used as underground piping (it comes in coils) for incoming water supplies such as the main line from the curb, although plastic piping is also used for underground water supply piping due to lower cost and ease of installation.

In my report I would note what these copper pipes are supplying-water, oil, gas, etc. and if they are water supply lines I would check the flow (as stated before) and note any reduction in “functional water flow” due to the reduced size.

Thank you so much. Super informative. I took notes!

Look for annealed copper tube to be stamped only. Copper pipe may be stamped and have inked labeling designating pipe schedule. Type M pipe is the standard for water distribution. Type L is considered an upgrade by local jurisdictions. Type K is primarily used in water service.