Tech => Rules Discussion => Topic started by: mspurk on January 20, 2015, 07:55:44 pm

Title: Pneumatic plumbing rules
Post by: mspurk on January 20, 2015, 07:55:44 pm
I have a pneumatic cylinder with a valve attached through copper hard tube. The joints in the copper tube are soldered. According to ASME this arrangement is good to over 1000 psi. I intend to run my system at 150 psi. Is there any reason this would be unacceptable? What information would I need to provide to the EO to show my system is safe?
Title: Re: Pneumatic plumbing rules
Post by: MikeNCR on January 20, 2015, 08:11:06 pm
I believe these would be the relevant sections of the rules:

9.5.All pneumatic components within the robot must be rated or certified for AT LEAST
the maximum pressure in that part of the system. You may be required to show
rating or certification documentation on ANY component in your system.

9.6.All pressure vessels must be rated for at least 120% of the pressure they are used
at and have a current hydro test date. (This is to give them a margin of safety if
damaged during a fight.) If large actuators, lines, or other components are used at
pressures above 250psi these will also need to be over-rated and are to be preapproved
for this event.

Pneumatics isn't my area, but given a reasonable reading of 9.6, assuming the copper portions are used at 150psi max, you may not need to get any sort of approval so long as they're not classified as "pneumatic components"

The "best" option would be to get the section pressure tested to 120% of the use pressure (if not higher) to avoid any issues.
Title: Re: Pneumatic plumbing rules
Post by: mspurk on January 21, 2015, 07:46:06 pm
Yeah I read 9.6 as pressure vessels which would imply pressure tanks to me. I can get it hydro tested, but it would be cheaper to cut the existing pipe off and replace with new rated tube.
My thoughts were it isn't much different than using threaded brass fittings. There is a rating and it is up to the builder to install it appropriately.