lucky you, relax. Trailers made prior to 1978 have copper lines, and you are safe. Our 1974 is safe, our 1971 has had half of it's lines frozen, so I guess it is beyond any danger now.
I am concerned about our 1990, and owners or trailers made between 1978 & mid 1995 MAYBE should be concerned too.
Since my first post, I have had time to review my notes. What concerns me about this 40/50psi is that the increase pressure our lines are subjected could hasten their demise.
Those who are not familiar with that problem should read the very informative thread by 83Excella Plastic Plumbing
A brief summary: "Gray polybutylene tubing was used in plumbing installed between January 1, 1978 and July 31, 1995. While it may leak within a few years of installation, the majority of leaks start to occur in the 10-15 year time frame." A lawsuit ensued.
It is then very important to keep water pressure low. I don't know if the difference between 40 & 50 psi is great enough to make a significant difference, but I will assume it is until proven otherwise.
Why are RV outfits and Shurflo been lying to us?
Is it because the "book" says "use 40", they don't have a 40, so it is easier to relabel a 50 into 40?
Am I making a big deal out of nothing like usual ?
RV owners were kept out of this lawsuit because of the low pressure used in RVs, compared to much higher psi in houses.
But if they lied to us, I am wandering about their liability when my trailer gets flooded.