CPVC piping

[kkr5]

Hello,

Can CPVC piping be used in a seawater application (discharge from SW pump)? What is the recommended support span for this piping?

 

[bimr]

Yes, it is resistant to sea water. Additional design considerations include abrasion resistance and weight. The contents of seawater are often highly abrasive and can shorten the life of the piping system.

Pipe spans demand on the pipe diameter. Pipe spans are as low as 5 Feet for 2-Inch pipe to 15 feet for 16-Inch pipe.

http://www.ipexamerica.com/Content/Products/Product.aspx?IsDownload=true&FileId=5438&ProductId=115

 

[MikeHalloran]

In terrestrial service (A/C condensate drain) it's not super impact resistant (big commercial lawnmower).

I'd be hesitant to use it in a boat.


Mike Halloran
Pembroke Pines, FL, USA

 

[Wilbur55]

How long does this installation need to last?

Though this is about sprinkler piping, the same reservations might be appropriate in other applications:

http://www.wheatland.com/wheatland-standard/fire-sprinkler/cpvc-sprinkler-pipe-31-flavors-of-risk-1

Common products that contractors could possibly encounter — like caulk residue or oil on French Fries — could potentially come in contact with the CPVC and may cause the system to drip, crack or fail completely.

“the overwhelming cause of failure is contamination of the CPVC pipes and fittings with incompatible chemicals.”

 

[bimr]

Wilbur55, fortunately for the OP, sea water is not on the incompatible list.

 

[europipe]

Bimr, I think Wilbur means on the outside of the pipe.

 

[bimr]

This is off post, but CPVC has been approved for years in many settings for fire sprinkler use.

Other than that, there are a few people who are trying to make a business out of product liability issues.

The quote “the overwhelming cause of failure is contamination of the CPVC pipes and fittings with incompatible chemicals.” is also taken out of context.

Reading further "Using GC-MS we successfully determined the root cause for the sudden increase in failures of CPVC pipe and fittings; i.e., the main contaminants responsible for most of the ESC failures were amines." However, the source of the amines was not conclusively determined.

 

[europipe]

Bimr,offpost, please define?
Worked years with this stuff.
It is in much cases no good.
especially when (sun)light is involved.
Why not use metal pipe?

 

[bimr]

The OP asked a simple question, is CPVP acceptable for sea water? The answer is yes.

All this nonsense regarding product liability for sprinklers is off post.

There is nothing wrong with the CPVC product when it is properly applied.

 

[MikeHalloran]

IF the OP is pumping seawater to some terrestrial installation, like a salt concentration pond, or a desalinator, and the CPVC is protected from sunlight, and collateral damage from pipe fracture is limited to some incidental leakage that does no serious harm, then I'm okay with using it.

IF the OP is pumping seawater within a boat, then I have a problem with using CPVC.
First, the seawater sucked into a boat is not necessarily nice clean salt water; it includes whatever has been dumped into the water in which the boat finds itself. The boat crew has no control over the composition.
Second, seawater is typically used within a boat to cool the engines. It typically takes a lot of seawater to do that, and the systems within the engine room are normally unattended, so a breach of the seawater piping can quickly flood the engine room, which often enough causes loss of the entire boat. That is a serious risk of considerable collateral damage, which does not balance well against a small savings achieved by not using serious marine grade material.

The OP has not come back to clarify the application, so an unconditional blessing of CPVC for 'seawater service', without further elaboration of the service's exact nature would be irresponsible.



Mike Halloran
Pembroke Pines, FL, USA

 

[georgeverghese]

My experience with an OpCo with mission critical sea water piping for firefighting applications in offshore platforms is 70:30 CuNi (or 90:10 CuNi?) - they used GRE for a while and switched out to CuNi due to structural strength concerns.

 

[Wilbur55]

I haven't received notifications for most replies.

Europipe is correct, I meant incompatible chemicals on the outside of the pipe; which should have been clear from the context.

I thought the claim about grease from french fries ruining a pipe was ridiculous until I did some research.

Crude oil might also be damaging to CPVC. Installers of pipe on an oil platform are not likely to do meticulous hand washing between handling oil production piping and this seawater piping.

How is a concern for compatibility between material selection and a proposed application "off post"?

 

[Gator]

Just to be a PITA I'm going to suggest that a "seawater application (discharge from SW pump)" need not be in a seawater environment, pumps at an aquarium would be one example.

Piping Design Central

 

[bimr]

The filling of water sprinklers with contaminated water and then letting the fire water system sit there pressurized for 20 years has got nothing to do with CPVC compatibility with sea water. That is why it is off post.

Read the report thoroughly. CPVC is still commonly specified for sprinklers.

 

[MikeHalloran]

We have been arguing with decreasing civility about how to answer the question in reflection of disparate contexts, in each of which the answer to the same simpleton question is different.

Let's all have a cup of tea, and relax until the OP comes back to rephrase the question within its own context.

Thank you.


Mike Halloran
Pembroke Pines, FL, USA

 

[europipe]

Mike, You're English? Tea
I'll take a beer.

 

[georgeverghese]

There are limits on hypochlorite dosing rates if you intend to use CuNi piping for seawater supply - in order to keep these dosing rates low, the seawater intake caisson should be well below the thermocline at this location.