Fire Water Piping Material

A possible problem with plastics is that they could be melted by the fire before the fire is put out. A dry type system might be better, or one could increase the pipe sizes to allow for deposits, or maybe the water could be treated. This is likely to be governed by local code(s).

well, you may be having marine growths that plug pipes = need for chlorine to sterilize the incoming sea water. In addition, carbon steel + salt water is a recipe for corrosion, so you need additives to this water to limit this. There may be a company that makes additives that control corrosion as well as marine growth.

The marine growth enter as microscopic larvae, that settle and then grow. They then will reach a limit of growth due to nutrient and/or oxygen deprivation = dead stuff that loses adherence and drifts and clogs pipes.

This is a mature field and an experienced engineering firm should provide solutions for this at the design and construction phase.

One of the best materials for sea water applications is Super Duplex Stainless Steel (ASTM Grade UNS32760S). This falls under the category of nitrogen-impregnated Duplex Stainless Steels and is made especially for sea water applications. However, this material is quite expensive.

Satish

Stainless Steel pipe would be by far the best option, it is lighter than lined pipework, more flexible in terms of fittings and supporting, strainers could be introduced into the line to alleviate the debris and algae/bio-mass issue, and it is a good heat resistant material. Corrosion resistance is also good, but as a previous contributor indicated, other less expensive options are available.

I have some useful data regarding stainless steel in my library specific to heat, corrosion and material adhesion characteristics in pipework applications, which may prove helpful to you, I will try to dig it out for you in the unlikely instance that other contributors cannot help you

Appreciate and thankx for everyone for your valuable input. I know good things don't come cheap. Which is cheaper on the long run - duplex stainless or cupro nickel or carbon steel with additives?

We use alloy 42 at 850 oC (1560 oF) for 4 hours at peak temperature at a time. Alloy 42 use to oxide and flake badly. End up developing glass and glass ink to coat alloy 42 and have run in salt water condition for more than 1000 hrs without failure.

The ink was from Global Applied Materials in India. If you need I can provide you the contact number so you you can discuss with them I am sure you will need to work with them for coating development to pipe

Good suggestion.

I remember doing some inspection of a water box for a desalination plant. The water box was fabricated using cupro nickel....... a bit expensive though...