Showing posts with label container. Show all posts
Showing posts with label container. Show all posts

Wednesday, July 30, 2008

Safety Info on Four Inch PVC Pipe

I went down to the plumbing supply house today and rounded up some info on 4 inch PVC pipe that I believe folks ought to know.





What I learned is:

1. There are more types of PVC pipe than you may suspect.

2. I know of three schedules: Sched 20, Sched 40, and Sched 80.

3. Sched 20 has 1/8" sidewall on 4 inch pipe. Sched 40 has 1/4" sidewall. Sched 80 has to be ordered(at least at the business I went to) so the sidewall thickness couldn't be checked.

4. There are at least two types of core: foam core and solid core. The foam core is NOT able to withstand pressure. If you buy pipe and see bubbles inside the cut end it is not worth a hill of beans as a container.

5. Pipe that does not have a pressure rating is not suitable to withstand pressure. The pressure rating is found just after the SCHED rating.

6. The plumbing supply house "might" cut the length you want, but SCHED 40 solid core pressure rated PVC pipe only arrives in 20 foot lengths. That means you are looking at 45-50 Dollars in outlay for a container that is about 8-10 inches long. Yikes!

UPDATED: More Info on PVC pipe

7. Great link on PVC pipe pressure ratings: Engineeringtoolbox.com. I note that the pressure rating on this site is noticably lower than the pressure rating of the pipe I bought. This is due to the figures being the industry standard. Individual pipe manufacturers are likely to exceed these numbers and will state so on thir product if they do. If not then go with the industry standard.

8. PVC pipe derates to 20 percent at 140F and long term failure occurs above that. Check the link at Engineeringtoolbox.com.


I think this means PVC pipe should be abandoned and move to one of the other plastic pipe materials unless a non-heat environment can be achieved. According to the charts, PB and PEX perform the best in heat conditions, but have about 40 percent of the strength of PVC. CPVC performs marginally better with heat, but has the same strength properties as PVC.

Thanks to commenters for the additional data and links!

Tuesday, July 22, 2008

First Operational Test of an Oil Sensor

I conducted the first test of an oil sensor and comment on the results in this film clip. The sensor I used was a Ford Idiot light sensor type. This type just causes a light to come on on the dashboard if the oil pressure fails.





My Observations

1. The switch closes at 3-5 pounds of pressure and the resistance goes to 1 Ohm.

2. The switch opens at about 3 pounds of pressure and the resistance goes to infinity.

3. Idiot light type oil pressure sensor switches are well suited to use as a control mechanism for electrolysis.

Monday, July 21, 2008

Building a Pressure Chamber to Test Oil Pressure Sensors

I got a crazy idea to test how oil pressure sensors actually work and this lab project is the result.






Parts List


  • (1) gas bottle, (never had gas is safe, used is cheaper)
  • (3) 1/2" black pipe tees
  • (3) 1/2" close fit black pipe (or the shortest pipe available)
  • (1) 3/4" to 1/2" Black Pipe Pipe Adapter
  • (4) 1/2" to 1/4" Black Pipe Adapter
  • (2) 1/4" brass male air connector
  • (2) 1/4" quarter turn air valves, male/female
  • (1) 1/4" air coupler, male
  • (1) 1/4" air coupler, female
  • (1) 1/4" Air Pressure Gauge
  • (1) 1/4" Air Coupler Quick Connect, female
  • (1) An oil pressure sensor that fits your vehicle


Personally I like to be able to drive my truck while I'm experimenting, otherwise I could just use the oil pressure sensor that's already on it.

The Ford oil pressure sensor I bought fits a 1/4" pipe adapter. Other makes and models may be different, so in that case you would have to adjust the parts list to get the sensor to fit. In the case of a metric sensor, fitment may be difficult without making your own adapter using a black pipe cap that you cut a hole in and tap to fit.

Lab Projects Articles


Next: Changes to the Test Pressure Chamber
Previous: Demo of Auxiliary Power Input on the Test Control Panel

Thursday, July 17, 2008

Why am I Using Glass Sugar Jars and Crayons?

I talk about using glass sugar jars to conduct and store experiments in and crayons to keep track of what's in the jar.