Non Re- usable pipes. 3

[mac60]

I am out of my depth perhaps, but, here goes. I need [for a process] to allow fluid into a vessel at just the right amount[this part is ok & resolved]. Then the pipe [which can be in 2 parts]must not be used again [to avoid contamination]. So, the system must break, not fit together again or otherwise be useless. Pipes can be made of plastic, glass, ceramics or similar [not rubber]. Size of pipe varies but never more than 1/2 inch in diameter.

Any help will be most gratefuly appreciated.

 

[NCMog]

I doubt you're going to find such a pipe. The very nature of a well designed piping system is that it maintains its integrity. Well I guess you could break a glass pipe, but that would be a safety hazard. Normally a situation like this would be dealt with via plant SOPs.

What is the length of pipe you are talking about? How many? Do you not have an opportunity to run a CIP and/or SIP cycle? (clean in place/steam in place) In the pharmaceutical/biotech world, that is how we deal with cleaning and sanitizing piping between batches.

 

[MikeHalloran]

Baxter makes a peritoneal dialysis kit that includes something along those lines. The kit includes a bag of saline that's plugged by a little colored plastic, well, doohickey, that's shaped sort of like a potato masher, but much smaller. It's hollow, but the hole inside doesn't go all the way through. The big end inserted into a nipple in the bag. A hose is attached to the outside of the bag's nipple. After the patient has made the proper connections to the apparatus that's been surgically inserted in their body, they start the fluid flowing by bending the tube at the nipple until the doohickey breaks in two. The smaller end of it is a loose fit in the hose, so once the doohickey has fractured, the saline can flow axially into the big end, radially through the fracture, and axially along and past the small end. The tube that encloses the doohickey is a loose fit around it, and has a smaller host bonded into its distal end, so the fractured part is captured.

Okay, it's sort of the reverse of what you seem to be asking for, but maybe it will get you thinking. I think it's a nice bit of material selection; the doohickey breaks like highly loaded glass- reinforced ABS. The plastic is strong but not tough. The tubing and the bag appear to be polyurethane; tough but not strong. The assembly withstands normal handling but the doohickey can be fractured by a patient's fingers.

-Mike-

 

[dicksewerrat]

Could you use some type of wheel arrangement? With a large number of 'pipes? As each fill cycle ends the wheel is turned to the next 'clean' pipe. The pipes would have to be sealed by some type of gasket. And removeable like cartridges in a gun cylinder. Maybe the cylinder could be switched out and then the pipes could be punched out and replaced.