ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Increasing demand factors in residential
by gfretwell - 03/28/24 12:43 AM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
Cordless Tools: The Obvious Question
by renosteinke - 03/14/24 08:05 PM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (Scott35), 268 guests, and 13 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
Joined: Oct 2000
Posts: 2,749
Member
What are the recommended procedures for grounding and bonding fiberglass piping in chemical atmospheres?

Are there any available documents, or publications that can be used by operator's?


Joe Tedesco, NEC Consultant
Joined: Mar 2001
Posts: 2,056
R
Member
Joe,

Are you referring to minimizing static electricity?

Joined: Oct 2000
Posts: 2,749
Member
Redsy:

Yes, that's one the reasons for this question.

The facility uses various highly flammable fluids, such as acetone, methanol, and ethanol.


Joe Tedesco, NEC Consultant
Joined: Nov 2000
Posts: 2,148
R
Member
Joe,
I don't understand how nonconductive piping can be bonded or grounded?
Don


Don(resqcapt19)
Joined: May 2001
Posts: 717
G
Member
Don,
In an explosive atmosphere you MUST bond your plastics because of the static, you create one VERY big problem if you don't

Joe, I always had to rely on the manufactures info for this. There is so little in the code, and even IEEE documents that you had to rely on the UL ratings and user guides.

NFPA 77 can be very instructive in this case as well.

Joined: Nov 2000
Posts: 2,148
R
Member
Geroge,
I know that sometimes a metallic path is provided to discharge static along a nonmetallic transfer system, but I don't consider that bonding or grounding of the nonconductive piping system. You can not make an effective grounding or bonding connection to a nonconductive object.
Don


Don(resqcapt19)
Joined: Jul 2002
Posts: 680
W
Member
Wouldn't the static buildup inside the piping, where the fluid flow is??? So wouldn't it follow that some type of wire inside the piping, possibly bonded to the core of the pipe. I've seen and installed lots of fiberglass piping. Never seen a static strap except on plastic(HDPE) piping that connected to a brass fitting at a termination

Joined: Oct 2000
Posts: 2,749
Member
I found a position paper from the "Fiberglass Pipe Institute" that verifies the hazards and supports some of the positive comments made here.

Quote
Nonmetallic fiberglass pipe and fittings are available with a grounding wire entrained in the resin and meets MIL-P-29206A for jet fuels and petroleum liquids.


Joe Tedesco, NEC Consultant
Joined: Nov 2000
Posts: 2,148
R
Member
Joe,
That makes a lot more sense. Now we are bonding or grounding a conductive object, not just a nonconductive pipe. There is some information in the IEEE Green Book that says a bonding/grounding path with a resistance of up to 1,000,000 ohms is sufficient to prevent the build up of static charges.
Don


Don(resqcapt19)
Joined: May 2001
Posts: 717
G
Member
Don,
There are many instances where a simple piece of PVC can harbor sufficient static to create an explosive atmosphere, especially along the inside wall of the pipe.

In these cases, you can also ty-wrap a simple piece of #12 alongside the outer edge to dissipate your charge. As long as it is continuous, the ohmic value can be as great as 1 meg with no harm to the value of the ground.

What !!! never made a rubber battery?

Page 1 of 2 1 2

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5