My new (to me) lift
07-05-2011, 08:39 AM
#16
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Location: Magnolia TX, just north of Houston, Red 1984 S
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Just a passing thought or two regarding "plastic water pipe" for high pressure air. Schedule 40 1/2" PVC (common household use rating) is rated for 600 psi, while schedule 80 (heavy duty household rated) is rated at 800 psi. My normal water pressure at my house is 90psi......not so certain that the plastic pipe cares if it carries water or air, my compressor maxes out at 125psi..... I like copper better for pressure air plumbing, but that is mostly because of its "cooling" properties over a 20 or 30 foot run.....
07-05-2011, 01:56 PM
#17
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I seldom disagree with Jim on things, but most common plastic pipe, particularly PVC and CPVC, is a serious no-no for air lines.
Choose carefully. Copper is probably the best (but is $$ now with all the WalMart dollars spending on copper in Asia), with steel/galvanized a second choice. Put drainable traps in at your workstations so you don't get water carryover into your tools. The failure mode on common plastic pipe is a violent explosion with plastic shrapnel. There are some soft PE options, but they cost as much as steel. Just easier to install if you get one of the hobby kits with the quick-connect o-ringed joints.
Back to work...
Choose carefully. Copper is probably the best (but is $$ now with all the WalMart dollars spending on copper in Asia), with steel/galvanized a second choice. Put drainable traps in at your workstations so you don't get water carryover into your tools. The failure mode on common plastic pipe is a violent explosion with plastic shrapnel. There are some soft PE options, but they cost as much as steel. Just easier to install if you get one of the hobby kits with the quick-connect o-ringed joints.
Back to work...
schedule 80 pvc is 800 PSI... much more than an air compressor will handle.
(the larger the pipe the lower the PSI ratings)..600 psi is for 1/2 inch pipe.
these ratings have a 2:1 saftey factor, meaning that the pipe should not burst until you double those pressures.
The only issue i can see is if they are in an area that they can be run over by a car when cold (brittle)...they could crack.
I work with the stuff almost every day, and see no issue with using sch 80 for the lines. My shop has had PVC air lines for over 15 years without a single incident.
07-05-2011, 06:23 PM
#18
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Thread Starter
I have a Bendpak four post so I have a couple comments:
1) At first I bought PVC for the air lines. After researching it further I returned it and went with a Goodyear rubber 1/2" air hose. In bulk it was cheaper than PVC, and it's designed for the job and MUCH easier to run. The PVC will likely fail eventually. It is not designed for that application. Usually it fails with cracks and leaks, sometimes it fails catastrophically. Either way, it's a hassle and risk I don't want. I've seen other failed PVC installations, both catastrophic and just leaks. Some have lasted a year, some 20+, but eventually they have all failed (that I have seen). Either way it was more of a pain than I wanted to deal with.
2) I have dual 4,500lbs bridgejacks, they look like the one in your photo. I run them with 90psi and they work fine. I do have a high CFM air flow rate available, but I think they'll run fine on less, just take longer to ratchet up. Same as with a pneumatic gun. A smaller compressor will drive it fine, just have to wait longer when the pressure drops.
3) If you don't have the assembly manual, you should contact Bendpak for it. It includes instructions for adjusting it. I would say it's pretty important to have.
1) At first I bought PVC for the air lines. After researching it further I returned it and went with a Goodyear rubber 1/2" air hose. In bulk it was cheaper than PVC, and it's designed for the job and MUCH easier to run. The PVC will likely fail eventually. It is not designed for that application. Usually it fails with cracks and leaks, sometimes it fails catastrophically. Either way, it's a hassle and risk I don't want. I've seen other failed PVC installations, both catastrophic and just leaks. Some have lasted a year, some 20+, but eventually they have all failed (that I have seen). Either way it was more of a pain than I wanted to deal with.
2) I have dual 4,500lbs bridgejacks, they look like the one in your photo. I run them with 90psi and they work fine. I do have a high CFM air flow rate available, but I think they'll run fine on less, just take longer to ratchet up. Same as with a pneumatic gun. A smaller compressor will drive it fine, just have to wait longer when the pressure drops.
3) If you don't have the assembly manual, you should contact Bendpak for it. It includes instructions for adjusting it. I would say it's pretty important to have.
07-05-2011, 07:50 PM
#20
Chronic Tool Dropper
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PVC plastic pipe doesn't like heat, doesn't like the oil in compressed air. It suffers from UV epoxidation when exposed to light. Good for buryin in the yard, not so great exposed. Biggest issue is the failure mode and the effects of the stored energy when failure occurs. I felt the same way for years and was all ready to use PVC, and was schooled on the issues by an expert. Use metal.
If you have time, take a look at the www.GarageJournal.com site, and do a little searching for discussions on this subject. Enlightened, you will probably go with metal. I know how we all feel about internet information and how correct things always are, but this is a pretty important issue.
Or call Manville and ask them about using their PVC for shop airlines.
If you have time, take a look at the www.GarageJournal.com site, and do a little searching for discussions on this subject. Enlightened, you will probably go with metal. I know how we all feel about internet information and how correct things always are, but this is a pretty important issue.
Or call Manville and ask them about using their PVC for shop airlines.
07-06-2011, 05:24 AM
#21
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Worked with a guy once who installed a BIG air compressor to power large Wienig 4 sider wood working machines and other various air equipment and he was told no problems to run in PVC. Glued and set all the pipes, left for 2 days over the weekend to cure, came in Monday morning, fired up the compressor and then there was a huge bang in the factory. Blew about 10% of the joints and destroyed 2 of the ceiling rafters. Blew a hole through the asbestos roof. He then put in copper piping with welded and water tested joints. No problems I heard of 15 years later. Know you are not running the large pressures but I would do it right, use the recommended hose.
Regards
Norm
86.5 S3
Regards
Norm
86.5 S3
09-05-2011, 06:46 PM
#22
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Thread Starter
The lift is in and working:
I haven't installed the air line yet for the rolling jack. I'm using a small portable compressor for the time being for the pneumatic locks. The HD-9ST (the narrow version of the Bendpak HD-9 series) is plenty wide for the S4. A GTS would be tight, but I believe you would still have an inch or two to spare.
The upside of the narrower lift is that it was easier to position to give me at least some working room on the far side. Unfortunately, that wall is very close to the garage door opening, so there isn't much room.
To allow me to get both cars in, I've removed the garage door opener and parked the 928 tail end first. That leaves me just enough room to open the door high enough to drive in a second car. If the future, I'll probably either buy a rolling garage door or move the current door closer to the ceiling and buy a jack screw opener. For now, this will work fine. BTW., my ceiling is about 10.5' high.
(please excuse the messy garage)
I haven't installed the air line yet for the rolling jack. I'm using a small portable compressor for the time being for the pneumatic locks. The HD-9ST (the narrow version of the Bendpak HD-9 series) is plenty wide for the S4. A GTS would be tight, but I believe you would still have an inch or two to spare.
The upside of the narrower lift is that it was easier to position to give me at least some working room on the far side. Unfortunately, that wall is very close to the garage door opening, so there isn't much room.
To allow me to get both cars in, I've removed the garage door opener and parked the 928 tail end first. That leaves me just enough room to open the door high enough to drive in a second car. If the future, I'll probably either buy a rolling garage door or move the current door closer to the ceiling and buy a jack screw opener. For now, this will work fine. BTW., my ceiling is about 10.5' high.
(please excuse the messy garage)
Last edited by EspritS4s; 09-05-2011 at 08:44 PM.
