Since bio diesel is so hard on rubber, I want to check on setup components. Is it possible to do some plumbing with PVC or even C-PVC? If so, what type of glue is compatible with bio diesel? What do I look for. Getting steel fittings just the right length, buggering up threads, making a trip for one fitting ... PVC is easier to work with to me. What about hoses and tubing? Will any clear tubing work? With pumps, I've seen some discussion about clear water pumps. Will bio diesel not break down any pump parts? Anything else as far as things that will break down I need to know about?

I also realize hard plastic fittings are commonly used, but they are EASY to mess up the threads. I'm thinking the best setup could be to have hard plastic fittings and use clear tubing (non-collapsing for suction hoses) so I can see if a clog were to take place or a whole number of reasons. But would bio diesel cloud the clarity over a few uses?

Look into PEX tubing, it should stand up to bd well. The crimp tool is expensive but needed. However I have had success by heating the tube with a heat gun, slipping in the fitting, and cranking down on a worm drive clamp.

As far as I know there is no such thing as a pvc glue that will hold up to bio, bio reactors with a lot of plastic are dangerous reactors.

Not to mention PVC has difficulty with heat as well.

sounds good. I'm doing a radiant heat project in my shop in the next month. Going to add an extra valve to the manifold for processing heat source. Maybe rig up a thermostat (if possible) to control flow and regulate heat. What about using clear tubing and hose clamps where heat is not used, only methoxide? I really think the visual advantage would be very useful if compatible.

As you can see there is a difference of opinion. White PVC works fine. Do not use C-PVC or gray PVC. I don't know how clear tubing would work.

What are you growing and burning?

PVC, along with pvc glue, is completely impervious to biodiesel, methanol, wvo and lye.

BUT...

It is NOT rated to handle heat, and it is relatively fragile. I personally think it is not safe in, on or around a processor.

CPVC (the tan stuff) is absolutely NOT resistant to biodiesel, and I know this from first hand experience. Don't use it ever.

Heavily cross linked polyethylene (AKA PEX) IS resistant to all of our chemicals, is somewhat more resistant to heat, is somewhat more robust/less fragile, and would still not be as safe as BIP, Black Iron Pipe. If you still choose to use PEX, make sure the fittings themselves are also PEX or something else that is bio resistant and corrosion resistant.

HTH,

troy

Do not use the white pvc pex fittings, as they will crack after they are in contact with bio.
My dry tank fittings were pex pvc and lasted only 6 months.

So, to summarize...

Plastic weak, fragile, brittle, often chemically incompatible and not so heat resistant.

Steel/iron strong, safe, heat resistant and 100% chemically compatible.

Finest regards,

troy

quote:

Originally posted by troy:
So, to summarize...

Plastic weak, fragile, brittle, often chemically incompatible and not so heat resistant.

Steel/iron strong, safe, heat resistant and 100% chemically compatible.

Finest regards,

troy

Not what I said.

Plastic works fine, is cheap and easy to work with. It will take the heat of brewing. Also easy to make changes to plumbing.

Mild steel/black iron is better. It does cost more and is more difficult to work with and acid will eat the stuff over time. It can take high heat.

Stainless steel is the very best. The cost is very high unless you can find scrap stuff that will work.

Dear Fuelfarmer,

I was not trying to put words in your mouth, but rather, stating my own opinion based on my experience as a natural gas pipe fitter (which sometimes included plastic products) and my (somewhat) extensive experience with biodiesel and plastic piping products.

Good discussion,

troy

PVC pipe comes in different wall thicknesses. The cheapest is "schedule 20". Don't use it. The next step up is "Schedule 40", which is more or less standard domestic water pipe. The heavy duty stuff is "schedule 80", and is generally stronger and tuffer than the lighter ones.

BTW, the "rated Maximum Temperature" for PVC pipe is only 140 degrees F. Above that temperature it loses strength, but most processors don't operate at much pressure. Schedule 40 is rated at around 200 psi at room temperature, and schedule 80 at over 300 psi.

I've seen processors (including some commercial ones) that used clear PVC pipe, but have not talked with any homebrewers with long-time experience with the clear stuff. Anyone out there have it on their processor? How is it working? What fittings did you use?

Cheers,
JohnO

I was told by an experienced biodiesel plant builder and operator to never use anything but white PVC if you are using PVC. He showed me some gray pipe that was mush.

Does schedule 80 come in white? When I get schedule 80 fitting they are gray.

Troy, no offense taken. I just have the need to point out that PVC will work. Is it the best of the best? NO, but it will work. Just don't be stupid. No special tools, threaders, or welders needed. Just cut and paste. I have seen a plastic processor with PVC plumbing over 160 F. That is an example of stupid. Nearly had heart failure.

Yes, schedule 80 pvc comes in white. Be sure to use schedule-80 fittings if you want the strength. They're white too. I've also seen sch-160, but only in larger diameters.

Cheers,
JohnO

Please read this and many other posts describing numerous real disasters caused by plastic pipe and hoses/hose barbs in processor setups. There have been houses burned to the ground in a matter of minutes. I would say that is more important than the relatively minor inconvenience of having to deal with threaded pipe. All the big box stores will cut and thread any length you want in addition to having a good selection of precut and threaded lengths available.

http://biodiesel.infopop.cc/ev...19605551/m/192103622

Use no plastic pipe or hose in your setup. It is DANGEROUS and WILL cause a SERIOUS ACCIDENT!!! It's not rated for the temperatures encountered in biodiesel processing. It doesn't provide any safety margin in case the reaction heats up on it's own for some reason (biodiesel reactions are generally exothermic. That means they produce their own heat). It's not rated for oil-based chemicals used (pvc is for water only). It's not resistant to impact. When two vessels are connected together by plastic pipe, there is the possibility of an electrical charge causing a spark and igniting the whole mess due to lack of grounding between the vessels. It will be degraded by acids and bases used in the process, eventually hardening, checking, and cracking. DO NOT USE IT UNLESS YOU WANT A BIG BIG FIRE!! Use steel pipe only and if using the acid process it would be advisable to disassemble and inspect the internal piping for wear every 50-100 batches. There is no need for plastic piping/ hoses/ hose barbs anywhere in the circulation loop. Maybe in the pump-out line, or something that's ALWAYS supervised, but never on the processor.

Any links to stories where PVC pipe failed and caused a fire?

does anyone have a time window on when PVC goes bad?
white?
grey?

forget CPVC..

PEX is not related to PVC at all!!! polyetheyne cross linked..


I ask about the PVC only because
all mine must be real special stuff its been on place for 3+ years..white and grey..I don't; have much grey but its still solid.

I do know hte stuff turns brittle over time..but it does this with or without exposure to BD.

glues to use..I used the blue water proof and the clear..not problems

I've also run temp's to 140F..

I've had Black iron develope holes from acid processing..

-dkenny