Material for watersupply plumbing in a residence? 2

[Lutfijc]

Hey everyone,

I'm in possession of a 5 storied residence. As of recent events a tenant was kind enough to bring (what seemed like) a small plumbing issue soon after moving in - a nonfunctional hand wash basin at the dining room. What seemed like a 30 minute plumbing work grew into a nightmare as each pipe required for removal and replacement prompted another threading higher up the order to crack upon a slight anticlockwise rotation. I called off any further repair work to assess the extent of potential damages and where investments would need to be made. I've got to know through dialogue with the local plumber(after showing him) that all the water supply plumbing are of galvanized iron(or it could be galvanized steel) and range in ID of 1.5" all the way down to 3/4" leading upto the faucets around each flat.

Before I carry on about the materials available at the local market for use such as PVC or the likes, I'd like to inform members reading that the residence is located very close to a coast/beach. We experience tides every day on average that last for a few hours due to which the ground water table as well as the main water supply are subject to receiving slightly salinated water. On top of that we had experienced a few months worth of water shortages which prompted us to take measures and introduce rain water catchments i.e rooftop water collecting into main water tank. So I'm confident that acidic rain water is also taking its toll on the ID alongside rusting/corrosion due to the salt.

At present I have access to MS, GS, GI and PVC pipes to work with and the PVC pipes are the cheapest around my locality. I'm a resident in Chittagong, Bangladesh and the residence is located here. The building receives direct sunlight from both the East and West while the pipes are exposed to the elements as opposed to newer constructions with concealed plumbing work, not to forget overhead sunlight. It was constructed a long while back, at least 20 years ago and the plumbing hasn't been touched since.

I'm in a dilemma on whether I should go with PVC but I'm not sure if what I have access all over the country is UPVC or CPVC(most likely the former). So if anything I'd love to have people shun my doubts and worries on which direction to go in terms of redoing my plumbing. I'd be really humbled to receive further information on how I can care for the new plumbing work too as the existing lines were neglecting badly.

Thank you for taking the time to read through this inquiry.

- Lutfijc

* If any further information is necessary, do ask and I shall provide!

 

[EdStainless]

So you have grabbed a wild animal by his tail.
I am with you, hesitant about using PVC in sun exposure.
Your current piping only survives because of the internal corrosion layer and the low water flows.
Here in the US the two options would be Cu or PEX.

One option that you have is to use what is available and paint it. I know that this is another maintenance issue, but a good coat of white latex paint will provide UV protection. Using the heaviest CPVC that you can find should give you a reasonable service life.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[Lutfijc]

Indeed, you pretty much summed up exactly what has been going through my mind!

From what I've learn't CU isn't widely used for plumbing merely due its price per foot. When the demand for a product/commodity goes below 50% the importers tend to cater to those items as unfeasible goods and therefore refrain from placing any future orders/shipments. CU tubing of lower diameters are commonly available for use with Air Conditioning units though and PEX is literally unheard of by the likes of the shop owners/importers.

That last line pretty much has offered a very simple and elegant solution - hmm I'll see what can be done about it though would you voice any concerns if the only form of PVC I have access to is UPVC? There is a long history of importers and manufacturers in my country providing misleading information i.e; it could very well be UPVC but is simply marketed as PVC and some will proclaim it to be CPVC in order to move sales. I may be interested in painting the pipes but what sort of paint am I supposed to limit myself considering the pipes will be providing families of 5+ members per floor on a daily basis?

I should also include that the infrastructure build for plumbing by our government are very dated(round 50 + years) and the aging pipes are the main reason why 75% of the country's water is rich in iron. Would maintenance shift if that factor is introduced? Speaking of which, what sort of maintenance should I look forward to perform if I move with (U/C)PVC plumbing?

where are my manners? EdStainless, You've been of great help though, thanks mate!

 

[Compositepro]

With the low cost and ease of installation of PVC it may very well be more cost effective to replace it more frequently than the alternative pipes. Nothing last forever.

 

[EdStainless]

The best that you can do is look at the product and read the line marking on it. It should reference the correct ASTM spec and have other information. If it doesn't check out when you Google it then find another dealer.
In order to paint PVC you do need to wipe it down with a solvent to clean it. But using white latex paint will provide years of protection.
As you have already learned, install unions at key locations. The fittings are expensive but the repairs will be so much easier.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube