Gas Pipe size questions

[gas112]

Your 1st link refers to form bends and elbows. It doesn't define them, but the figure it calculates for 2 off 90° elbows, 0.4mb, is close to my figure for a mitre (or sharp corner if you prefer). I've never seen one either, in copper anyway.
Another online one

Gas Pipe Calculator

shows a picture of a sharp elbow. That also calculates ~ 0.4mb for 2. Both sites gives calcs for steel pipe, where a welded mitre bend is a possibility.

How do you know that?

The only way we'll know who is right is to do some measurements, and I can't see that happening. And do calm down!

We would need more data, is it a 22 x 22 tee followed by reducers, or a reducing tee, and which branches go where.
But I think we've beaten this to death, and I still say the OP doesn't have a problem.

read what the original poster actually put.
Pure and simple your calcs were wrong

 

[fixitflav]

read what the original poster actually put.

I did

Pure and simple your calcs were wrong

You're not in a position to claim that.

I tried to educate you about mitre elbows, but you didn't comment. If you've been selecting that in your online calculator all your working life, you've been overestimating pressure loss, and potentially telling a customer he must increase a gas pipe size when it's unnecessary.

 

[danfre]

Never seen a mitre elbow and I would always take gas 112 advice

 

[gas112]

I did

You're not in a position to claim that.

I tried to educate you about mitre elbows, but you didn't comment. If you've been selecting that in your online calculator all your working life, you've been overestimating pressure loss, and potentially telling a customer he must increase a gas pipe size when it's unnecessary.

wtf are you on about mitred bends which you say you have never seen on copper but want to bring them into the calcs .
the OP has not said he has pulled bends he has said he has the standard every day elbows that are fitted day in day out every minute of the day on pipe runs .
No when i size a pipe run i do it properly for what ever is used in the run ie pulled bends / /tees /elbows etc .
So go and educate yourself on what is used on everyday domestic pipe runs in the UK

 

[fixitflav]

mitred bends which you say you have never seen on copper but want to bring them into the calcs .

I don't want to bring mitred bends into the calcs, I was just pointing out that your pressure loss is based on bends in your online calculator which it treats as mitred bends, so overestimates the pressure loss. I suppose that's better than underestimating, but it doesn't mean it's right.

No when i size a pipe run i do it properly for what ever is used in the run ie pulled bends / /tees /elbows etc .

Yes, and that should include using correct bend input, not a mitre bend when it isn't.

what is used on everyday domestic pipe runs in the UK

No problem if you use the correct inputs, but as above, you're not doing that.
There are several online calculators, and they'll all give slightly different answers. I've been doing liquid and gas flow calcs most of my working life, so I know what I'm talking about.

I don't know why you're getting so wound up about this, I thought we'd all agreed the OP doesn't have a problem.

 

[gas112]

I've been doing liquid and gas flow calcs most of my working life, so I know what I'm talking about.

Shame you dont know how to do them correctly or follow simple charts but hopefully this thread will help you in the future

 

[fixitflav]

You're getting silly now. If you use the online calculators you have to enter the right data, in this case the right type of bend. I've tried to explain the difference between an elbow and a mitre bend but it hasn't sunk in.
Using elbows, the online calculators give 0.68-0.69mb, not 0.8881mb as in your #9.

 

[gas112]

You're getting silly now. If you use the online calculators you have to enter the right data, in this case the right type of bend. I've tried to explain the difference between an elbow and a mitre bend but it hasn't sunk in.
Using elbows, the online calculators give 0.68-0.69mb, not 0.8881mb as in your #9.

and you need to read what the actual op put and stop going on about mitre bends which are not and never have been used on standard domestic copper installations let alone on 15mm but that hasnt sunk in has it
. No they dont give the figure you are coming yup with . Try using them properly .

 

[fixitflav]

which are not and never have been used on standard domestic

I know, that's the whole point, so you shouldn't use them in the online calculators.

With the right inputs

Gas Pipe Calculator gives 0.678mb

Gas Pipe Sizing Calculator gives 0.693mb

What figures do you get?

 

[gas112]

I know, that's the whole point, so you shouldn't use them in the online calculators.

With the right inputs

Gas Pipe Calculator gives 0.678mb

Gas Pipe Sizing Calculator gives 0.693mb

What figures do you get?

as i said use the calculators correctly two 15mm elbows and 1 metre of 15mm pipe with the actual figures from a logic plus 30 does not give you those figures are you some sort of halfwit that struggles to put in the basic information ?

. please attempt to show me a breakdown of your comment ie pipework /fittings

 

[fixitflav]

two 15mm elbows

It's not elbows, it's form bends. Elbows (on these 2 online calculators) are sharp (mitre) bends, there's even a picture for those who have difficulty with the difference

show me a breakdown of your comment ie pipework /fitting

Gas Pipe Calculator Enter 33.8kW, 3.14m3/h, 2 off 90 form bends, 1m pipe, 15mm copper pipe

Gas Pipe Sizing Calculator Enter 33.8kW gross, pipe type 15mm copper, 1m pipe, 2 off 90° Form Bends

Let me know what you get.

 

[gas112]

It's not elbows, it's form bends. Elbows (on these 2 online calculators) are sharp (mitre) bends, there's even a picture for those who have difficulty with the difference



Gas Pipe Calculator Enter 33.8kW, 3.14m3/h, 2 off 90 form bends, 1m pipe, 15mm copper pipe

Gas Pipe Sizing Calculator Enter 33.8kW gross, pipe type 15mm copper, 1m pipe, 2 off 90° Form Bends

Let me know what you get.

FFS stop putting what you think it is and put what the OP actually put its 2 elbows not formed bends jesushchrist

 

[fixitflav]

I asked you to let me know what you get. What's the problem?

FFS stop putting what you think it is and put what the OP actually put its 2 elbows not formed bends jesushchrist

How many times do I have to explain it? I gave details of the headloss factors for both types in #12 and #15. Didn't you understand the picture in the online calculator?
I would hope you're a competent plumber, but you clearly don't have the intellectual capacity to discuss this.