does PVC pipe belong on a boat?

does PVC pipe belong on a boat?

  • Yes

    Votes: 4 44.4%
  • No

    Votes: 2 22.2%
  • Only if you're building a cheap bong

    Votes: 3 33.3%

  • Total voters
    9

SimonGH

Member
365
74
Westbrook CT
As usual I think the answer is “it depends”.

I don’t think you should use it below the waterline, but for non critical things like Sass mentions I think it’s ok.  What does ABYC say?

 
Not sure about ABYC but the class societies don't care. DNV, RINA, ABS It's all about the valve on the hull not what's connected to it.  It's still regularly used for chemical dosing into seawater lines in seachest applications.  The big no's are, never where it can freeze, never where it will move or flex excessively and never in high pressure applications.  I know people use it for compressed air but I never would.  Any black or grey water runs should use rubber unions to separate runs and eliminate stress.

 

casc27

Super Anarchist
2,345
129
It truly does depend. My boat has PVC cockpit drains (They run out the transom above WL) and the rudder post tube is also PVC. Both have been in place since construction in 1978 and still intact. Can be a useful material. Made some great shade umbrella holders in 5 minutes with some pvc pipe and zip ties once...

 

DDW

Super Anarchist
6,252
987
Of course, everything in its place and properly done. No rigidly fixed runs. And of course it can be used for high pressure fluid, just not high pressure gas. You can tidy up a lot of installations with it, not practical of possible with hose. 

ryLHFem.jpg


 
Of course, everything in its place and properly done. No rigidly fixed runs. And of course it can be used for high pressure fluid, just not high pressure gas. You can tidy up a lot of installations with it, not practical of possible with hose. 

Always curious how do you bend PVC?  Have only run glued stuff, lots of other composite stuff that have run with a pipe or tube bender but never PVC.

 

slug zitski

Super Anarchist
5,103
819
worldwide
Fill the pvc with hot sand , then use a heat gun to concentrate heat on the bend zone , then bend and let cool 

the sand keep the pipe from collapsing 

tight radiuses  are difficult to achieve 

there are professional heating elements that you insert into the pipe as well as other methods like plugging the ends , pressurizing the pipe with air   Then heating to bend . The air pressure keeps the pipe from collapsing 

naturally small pipes are easy to manhandle and bend , large diameter  are a bit more work 

Keep your bend away from the end fittings  

the bent pipe always seems to get out of round 

 

DDW

Super Anarchist
6,252
987
I did it with a spring of the right size inserted in the bend area. Sand is kind of messy, have to cap the ends, etc. PVC has a fairly wide plastic range, too hot and it will start to bubble but it is not as critical as say ABS or polycarb. Heat it evenly and patiently with a heat gun, on SCH80 it takes a little while to soak through. Then bend and hold with gloved hands while it cools to prevent spring back,  remove the spring. If you are expecting to use it with hose, you must first turn the ends to reduce the diameter. In the US, SCH80 1 1/4" is about 1.661" OD, so turn it to 1.5" for that hose. You can see in the picture I only do the ends, requires a little planning to get the length right. 

Different brands of PVC pipe have slightly different softening characteristics, I found the clear version in the pictures worked really well, plus you could see what you had for dinner last night. It was sourced from McMaster Carr. 

Here is another example (note: never mount a Henderson pump that way!).

wjxGGd1.jpg


 

sailak

Super Anarchist
2,865
46
AK
Being impervious to to holding tank odor is a huge plus.  I don't use it below the waterline and prefer schedule 80 when available.  Protect it from potential impact damage, use it where it is appropriate, and install properly and it will last the life of the boat easy.  There have been threads on this in the past.... they tend to look like anchoring threads after a while.  

 

slug zitski

Super Anarchist
5,103
819
worldwide
Being impervious to to holding tank odor is a huge plus.  I don't use it below the waterline and prefer schedule 80 when available.  Protect it from potential impact damage, use it where it is appropriate, and install properly and it will last the life of the boat easy.  There have been threads on this in the past.... they tend to look like anchoring threads after a while.  
Hard plumbing Pvc or PP needs to be properly supported with pipe clamps and assembled with attention to detail 

723BBE2A-24AD-4C36-9190-DB07424820FA.jpeg

 

Training Wheels

Anarchist
864
52
On my boat
Not sure about ABYC but the class societies don't care. DNV, RINA, ABS It's all about the valve on the hull not what's connected to it.  It's still regularly used for chemical dosing into seawater lines in seachest applications.  The big no's are, never where it can freeze, never where it will move or flex excessively and never in high pressure applications.  I know people use it for compressed air but I never would.  Any black or grey water runs should use rubber unions to separate runs and eliminate stress.
Also not a good idea to use on fire water systems, particularly in an engine room. Don’t ask me how I know…….

 
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