I wasn't looking at a table. I was using the mr combi pipe size app and for the length of 15 I have with 1 elbow you won't get higher, needs to be 22
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Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws
I wasn't looking at a table. I was using the mr combi pipe size app and for the length of 15 I have with 1 elbow you won't get higher, needs to be 22
App. and Tables in agreement 2.9 flow gives 3 meters and 20 meters for 15 &22.
Length 700mm pressure drop 700/3000 & 700/20000 which equates to the 0.233 & 0.035 given by App.
Phil also right with flow through 700mm length of 15mm. 1/4 of 3 meter length could be expected to give double the 3 meter flow, ( L X Q X Q approx constant).
Length 700mm pressure drop 700/3000 & 700/20000 which equates to the 0.233 & 0.035 given by App.
Phil also right with flow through 700mm length of 15mm. 1/4 of 3 meter length could be expected to give double the 3 meter flow, ( L X Q X Q approx constant).
I will do from now on! But from what Phil and Joni say I should get enough flow from that short run of 15 ... so what gives?
N
newcastle phill
N
newcastle phill
I dont use apps or rather put an over reliance on them. Pen and paper is best. But ive downloaded one that says different anyway which is more in line with my ready reckoning.
And 30kw is 30kw wether its vaillant, ideal or heatline - its not the boiler. As this demonstrates that small bit of run can handle upto a theoretical 45 ish kilowat
Edit.
Yep accurate drawing of the run.
And 30kw is 30kw wether its vaillant, ideal or heatline - its not the boiler. As this demonstrates that small bit of run can handle upto a theoretical 45 ish kilowat
Edit.
Yep accurate drawing of the run.
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I dont use apps or rather put an over reliance on them. Pen and paper is best. But ive downloaded one that says different anyway which is more in line with my ready reckoning.
And 30kw is 30kw wether its vaillant, ideal or heatline - its not the boiler. As this demonstrates that small bit of run can handle upto a theoretical 45 ish kilowat
Edit.
Yep accurate drawing of the run.
What app is that Phil?
Agreed re: heat input ratings.. I've tried drawing it and my drawings are confusing.. but basically there are 24 elbows, 2 45s and approx 14 meters of 28mm.
I hear you about the hob. If need be I'll change it. But even with the hob disconnected from the supply it didn't change the readings I got for the boiler.
Was the 21.5 at the meter with the boiler on max or just with the hob on.
And as everyone elce is saying dont have the hob and boiler both of the same section of 15mm pipe.
And as everyone elce is saying dont have the hob and boiler both of the same section of 15mm pipe.
Was the 21.5 at the meter with the boiler on max or just with the hob on?
And as everyone elce is saying dont have the hob and boiler both of the same section of 15mm pipe.
And as everyone elce is saying dont have the hob and boiler both of the same section of 15mm pipe.
- May 23, 2015
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found this mate and thought of you
https://twitter.com/irbheating/status/834063695613423618
incoming 20 mbar
gas test nipple 15.7 mbar
https://twitter.com/irbheating/status/834063695613423618
incoming 20 mbar
gas test nipple 15.7 mbar
Where can I get these compression test points???? I've searched but can't find them
- Dec 23, 2011
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Use one of these
https://www.bes.co.uk/22-mm-x-22-mm-x-1-2in-tee-compression-x-compression-x-bsp-f
With one of these
https://www.bes.co.uk/1-2in-x-1-8in-hexagon-bsp-parallel-reducing-bush
And one of these
https://www.bes.co.uk/test-point-nipple-brass#product-details-tab
https://www.bes.co.uk/22-mm-x-22-mm-x-1-2in-tee-compression-x-compression-x-bsp-f
With one of these
https://www.bes.co.uk/1-2in-x-1-8in-hexagon-bsp-parallel-reducing-bush
And one of these
https://www.bes.co.uk/test-point-nipple-brass#product-details-tab
- May 23, 2015
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15mm or 22mm to 1/2 t and then reducing bush from 1/2 to 1/8th
- May 23, 2015
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So, upped the pipework to 28 in basement, cut in a test point under the boiler and proved pipework was fine at 1mb drop.. still getting 12 working at meter. So I call NG. Guy says, don't run boiler on max rate, just run it normally because we don't test in max rate. Says if he gets good wp at meter at normal rate he's leaving. So I start to call gas safe register. He says run the boiler on max rate. He then finally accepts there's a problem with service pipework and calls it in!!!!!!
He reckons by running a boiler on max rate will generally always get lower than 19 wp at meter. Really? I say. I've never seen this before at the meter when I've done installs. Reckons that's how it is.
Jesus H Christ!!!!
He reckons by running a boiler on max rate will generally always get lower than 19 wp at meter. Really? I say. I've never seen this before at the meter when I've done installs. Reckons that's how it is.
Jesus H Christ!!!!
- May 23, 2015
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Ok.. so back to the original job on this post..
I fitted a Vaillant 30kW system boiler and upped the pipework in 28mm from meter to boiler as boiler and hob wasn't getting enough gas
I've now added a test point to both boiler and hob. I've also teed the hob off the 28 which I brought further up underneath the boiler..
I added the test point on the 15mm.. so!
Standing @ meter 25mb
WP @ meter both app 21mb
WP @ meter 1 app 21.5mb
WP @ boiler test point 20mb
WP @ hob test point 20mb
WP @ boiler with hob on 19mb
WP @ hob with boiler on 19mb
Have told custard to replace hob as burners went out with just hob on- hob is 30 years old.
I expected to see a working pressure of 20 at both appliances when both on.
Pipework is not undersized.
Why am I only getting 19????
These are my pipe calculations for what's currently there..
I fitted a Vaillant 30kW system boiler and upped the pipework in 28mm from meter to boiler as boiler and hob wasn't getting enough gas
I've now added a test point to both boiler and hob. I've also teed the hob off the 28 which I brought further up underneath the boiler..
I added the test point on the 15mm.. so!
Standing @ meter 25mb
WP @ meter both app 21mb
WP @ meter 1 app 21.5mb
WP @ boiler test point 20mb
WP @ hob test point 20mb
WP @ boiler with hob on 19mb
WP @ hob with boiler on 19mb
Have told custard to replace hob as burners went out with just hob on- hob is 30 years old.
I expected to see a working pressure of 20 at both appliances when both on.
Pipework is not undersized.
Why am I only getting 19????
These are my pipe calculations for what's currently there..
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- May 23, 2015
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O
Old Account
Aren't you allowed to have 4mbar drop on an existing pipework with an u6/g4 Meter over a two minute test Periode ?
O
Old Account
- May 23, 2015
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1.5 mbar with one appliance running and much better than before
And I'm sure your loosing .5 mbar on that 15mm
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One thing I did notice that I haven't seen before, all the readings pulsated on the gauge.. half a bar. Just went up and down constantly by half a bar.. dodgy regulator? Or is that normal?
- May 23, 2015
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Could be but its normal for it to move up and down a wee bit around .5 I would say is normal
Without seeing it it's a guess what do you think ? Are you happy with the results?
I'm happy that they're better, but not happy I'm getting a 2mb drop across pipework. But then, I'm not as experienced as you so if you say it's ok I'll go with that and put in a new hob, long as the flame pic and simmer are good I can call it a day..
- May 23, 2015
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Yea you can double check by phoning your friends up at Nat grid about the reg 😀
Do you know age of reg / what meter is in imperial or metric ?
- May 23, 2015
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Ok cool.. now all I gotta do is retract an incorrectly notified hob to HSE lol
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