| Author | Message | ||
     Christopher Williams Unregistered guest Posted From: 50.84.174.74 |
Hello all, I just rebuilt the accumulator spheres on my 1977 Shadow II, and am now researching getting a nitrogen charge in them. I have access to a large tank of nitrogen, but am in need of what other components are required to charge and test them correctly, such as the specific fittings, regulator, etc. Has anyone made a list of items required to charge them? If so, I have yet to stumble across it, and would appreciate being pointed towards the information. Thank you, Christopher Williams (Message approved by david_gore) | ||
| David Gore Moderator Username: david_gore Post Number: 2455 Registered: 4-2003 |
Christopher, If my memory is correct, Bill Coburn has covered accumulator recharging in Tee One Topics. Travelling at the moment and will try and find this information over the weekend unless someone else can provide it in the meantime. http://rrtechnical.info/TeeOne/teeone.htm . | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1638 Registered: 5-2012 |
Hi Christopher It depends on the feed from your nitrogen tank. When I re-charged my accumulators I found the local company required my accumulators to have a standard schrader valve fitting. The diameter of the thread on the charging port of the accumulator was too great to fit the schrader valve direct so I used a Watts A762 3/8 1/8 reducer coupling. I bought this from the local hardware store (Lowes) and then got the local hydraulic specialist to fit the schrader valve, to this coupling. The whole thing cost less than 20 bucks. You state in your entry about the need for a regulator. If the nitrogen cylinder you have access to does not have a regulator it will be expensive to buy one. They cost several hundred dollars. It may be more cost effective to find a company with their own setup and ask what type of valve you need to fit on your accumulator. The local company that re-charged my accumulators charged $10 per accumulator. From memory, I believe the line Bill Coburn (tee-one topics) used connected directly onto the accumulator port. Geoff | ||
| Kelly Opfar Prolific User Username: kelly_opfar Post Number: 153 Registered: 7-2004 |
The threads on the charging port are 5/8"-18. The adapter is sealed with an O-Ring. Here is one knucklehead that sells the adapter: http://www.britishtoolworks.com/ . | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 2220 Registered: 6-2009 |
I've posted it before, and will post it again: SY Accumulator Recharging Unit & Recharging Steps | ||
| richard george yeaman Grand Master Username: richyrich Post Number: 712 Registered: 4-2012 |
Brian thank you for your input again. Richard. | ||
| Kelly Opfar Prolific User Username: kelly_opfar Post Number: 154 Registered: 7-2004 |
I love Brian's paintball nitrogen tank for sphere charging done at home. Jean-Michel originally came up with the kit and the fitting he is using was selected by trying different fittings on his accumulator charging port at the hardware store. The FIP (Female Iron Pipe) fitting that he specified is simply a 3/8" NPT fitting. This pipe designation does have 18 threads per inch - the same as the accumulator charging port - but most NPT threads are tapered. Tapered threads are meant to seal with an interference fit - they get tighter as they screw together. If you were to screw a tapered NPT fitting on the accumulator charging port, it would get less sloppy as it screwed on, but would really only be hanging on by the last thread and a half(!). There are straight 3/8" NPT fittings. These are meant to use a seal such as an O-Ring or a rubber washer (like the water supply lines on sinks and toilets). This fitting might have more threads engaged and would feel better screwing on but it is still not the right tool for the job. In hydraulic terms, 1000 psi is hardly anything. Nonetheless, when I charged my accumulators, I secured them in a steel cage and hid behind a steel wall. I would be terrified if I was using a FIP NPT fitting. The right fitting can be easily made if you have access to a lathe. One end is drill and tapped with a 5/8"-18 bottoming tap and the other end is tapped with 1/4" NPT thread so it can be adapted to whatever hose your charging tank has. Drill an 1/8" hole all the way through for flow.  . | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1639 Registered: 5-2012 |
Hi Kelly When I rebuilt and recharged my accumulators in 2012 we were not acquainted with you or your Company britishtoolworks.com. It is great to have you here making things safer for us all. When I come to recharge my accumulators I will be ordering new charging fitments from you. As an aside, I get comfort from the fact the accumulator spheres are stress tested at well over 2000 psi every time you drive the car. Putting nitrogen in at 1000 psi doesn't seem so worrying when you are aware of this. Nevertheless, I will still insulate myself from the spheres, as you did, when I next need to recharge them. Geoff | ||
| Kelly Opfar Prolific User Username: kelly_opfar Post Number: 155 Registered: 7-2004 |
Geoff, The accumulator spheres are seriously overbuilt. They look to be able to hold exponentially more pressure than they actually do. 2000 lbs of pressure is still nothing in hydraulic terms but it could easily tear one thread off of a pipe fitting. For comparison's sake, new diesel trucks have 25,000 pounds (yes, thousand) of fuel pressure at the injectors. The weak point when charging will always be the fittings between the charging port and the regulator. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1640 Registered: 5-2012 |
Hi Kelly So I guess when you said "Nonetheless, when I charged my accumulators, I secured them in a steel cage and hid behind a steel wall." even though you were using your own fittings, you were just being super safe. Geoff | ||
| Kelly Opfar Prolific User Username: kelly_opfar Post Number: 156 Registered: 7-2004 |
We'll, it was my first time ....  | ||
| Christopher Williams Unregistered guest Posted From: 50.84.174.74 |
Thank you all for the suggestions, and to Brian and Kelly for the tool information. I wound up actually going the route Geoff suggested, and carried them over to my local vintage RR/B specialist, and he is going to charge them up for me. I also wanted to mention, Kelly, your tool selection is amazing. I wish I did not own some of the ones I've already purchased and I would have bought yours instead. My next items will be from you. (Message approved by david_gore) |
