bs en 806-3 pipesize

[leiadad]

Yeah that explains a bit, the pressure loss/gain when elevated would be the same regardless of pipe size. the only difference is the fact that 6700 or 8338 gives the opportunity to work out the total head loss and 806 doesn't. I'm assuming that the pressure loss would then need to be worked out by the designer to produce a minimum of 1 bar dynamic pressure at any fittings.

 

[leiadad]

so I am also assuming that because the simplified method (806) does not account for fittings or for losses through valves then the designer would have to take fittings as a percentage loss and valves as metres head lost when working out pressure loss within the pipework to make sure that the 1 bar pressure available at taps is achieved.

 

[chris watkins]

806:3 does what is say on the tin -
As far as I can see it simply provide a quick way of selecting pipe sizes for H&C systems against the appliance supplied from it, within a set pressure range.
Given that most modern systems are high pressure so pipe / fitting losses have such a small effect on the discharge would we need to alway calculate these ?

Do a couple of simple calc's using 6700, one high (say 3+ bar) one low (say 3 metre head) using the same fittings each time.
Then think about the advantage of using 806 in real life albeit with the limitations.

 

[fixitflav]

The only other way I can put it would be, if I was planning for a building with 6 loading units and 25 metres height, with an initial pressure of 3 bar, then surely the 15mm pipe recommended in 806 would be no good due to the initial loss of head on vertical riser

You need to think about it logically, and separate static heads from friction losses. It might help to have a talk with your tutor to get you started. If you're working on a heating system, and it sounds like you are, it's almost certainly a closed loop so there is no net static pump differential. But you still need to ensure there is positive pressure (ie above atmospheric) at the highest point. Maybe you're aware of that, hence reference to 25m height and 3bar.

 

[Chuck]

If you're working on a heating system, and it sounds like you are

No, he is using BS EN 806-3. ("Specifications for installations inside buildings conveying water for human consumption.")

 

[Chuck]

My point was that a lot of people who work in unis are lazy sods and probably couldn't be arsed to make the point I was making,

Not sure how you got to that from some guy wanting an internet forum to do their homework for them...

 

[fixitflav]

No, he is using BS EN 806-3. ("Specifications for installations inside buildings conveying water for human consumption.")

OK thanks, so he does have to account for static head. The principles I was talking about still apply.

 

[leiadad]

nobody asked for homework to be done chuck, the forum is about asking questions that we are unsure of, if you have nothing good to say then best say nothing

 

[chris watkins]

nobody asked for homework to be done chuck, the forum is about asking questions that we are unsure of, if you have nothing good to say then best say nothing

Now don't spoil the thread it was meant only as a bit of fun I am sure.

GSR & going to Uni, I am impressed tell us more?
Practical with thirst for knowledge, a man after my own heart, I would have loved the opportunity to study, its taken 40 years still I guess that is Plumbing for you.