The IET is carrying out some important updates between 17-30 April and all of our websites will be view only. For more information, read this Announcement

Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 59 replies
  • Subscribers 31 subscribers
  • Views 4850 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

bonding a short section of water supply pipe

wallywombat
In a victorian terrace house, a lead water supply pipe enters the damp cellar, runs about a meter along the wall to the main brass stopcock, then converts to plastic pipe before exiting the cellar to the rest of the house (which is likely to be a mixture of copper and plastic). The stopcock is a couple of feet away from the CU. Should the supply pipe be bonded? My feeling is no, but I'd be interested in other opinions.


While I'm on the subject, a more general question. Why must any bonding be done after the main stopcock? For example where the supply tees off immediately after the stopcock, is it better to bond one of the tees, or bond just before the stopcock? Where there is a long run of supply pipe before the stopcock, is it better to bond after, with a long MPBC run back to the MET, or bond it near the MET even where that's before the stopcock?
Parents
  • 0
    I would not want to fix a clamp onto soft lead.

    There's nothing soft about lead water pipes on incoming mains water supplies. As they have to withstand 10 bar or more they're very thick walled - the ones I've cut out looked 25mm or more outside diameter but the inside was smaller than a pencil. You'd have difficulty crushing them with a lump hammer never mind as BS 951 clamp.


    Lead gas pipes (and perhaps water pipes fed from a cistern) are a different matter - has they had to withstand far lower pressure they were usually much thinner walled - so more care is needed. The old trick was to put the clamp over a joint to copper or meter tail - where the lead pipe would be reinforced by a copper or brass tube inside it. I reckon the reference in the regulations to hard pipework is more to avoid the flexible corrugated pipes you now often see on gas meters these days.


       - Andy.
Reply
  • 0
    I would not want to fix a clamp onto soft lead.

    There's nothing soft about lead water pipes on incoming mains water supplies. As they have to withstand 10 bar or more they're very thick walled - the ones I've cut out looked 25mm or more outside diameter but the inside was smaller than a pencil. You'd have difficulty crushing them with a lump hammer never mind as BS 951 clamp.


    Lead gas pipes (and perhaps water pipes fed from a cistern) are a different matter - has they had to withstand far lower pressure they were usually much thinner walled - so more care is needed. The old trick was to put the clamp over a joint to copper or meter tail - where the lead pipe would be reinforced by a copper or brass tube inside it. I reckon the reference in the regulations to hard pipework is more to avoid the flexible corrugated pipes you now often see on gas meters these days.


       - Andy.
Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines