Gas supply for Vaillant 937 / Copper or Plastic

[doitall]

How many bends.

And what else is connected to it and where.

 

[simond]

BigBurner wrote:


He is asking questions so appears competent enough.

Nixt wrote

Familiar looking comment. BigBurner, would you, by any chance, be connected with Doctor Drivel, Water Systems, Balenza (TBC) or Richard Hanson-Granville?

Funny you should say that, I was thinking just the same thing about another post from this fellow. The boilers he recommends, the phrases, isn't that a coincidence?

I would give BB an 75% chance of being the latest incarnation of DD/WS etc, if I were a gambling man.

 

[gas4you]

The 937 is just an 837 on the front of 2 storage tanks basically and an 837 needs 4m3/hr when flat out on H/W.

As previously said, in theory 30M copper (equivalent length) should deliver 4.7m3/hr, but in the real world I would restrict this to 20m with anything more being installed in 35mm.

The tables we work to are known to be out, as no doubt we have all found in the past.

 

[doitall]

The 937 is just an 837 on the front of 2 storage tanks basically and an 837 needs 4m3/hr when flat out on H/W.

As previously said, in theory 30M copper (equivalent length) should deliver 4.7m3/hr, but in the real world I would restrict this to 20m with anything more being installed in 35mm.

The tables we work to are known to be out, as no doubt we have all found in the past.

So are your sums gas4you

The 937 = 37 Kw= 3.45 M³/hr.

Subject to the total bends 28mm will eat it.

10-12m of 28mm will pass 8m³/hr.

 

[gas4you]

MI's state that an 837/937 is rated/needs 4m3/hr, with the smaller 831 at 3.3m3/hr.

As we all know MI's over rule anything else, even your calculations

 

[doitall]

MI's state that an 837/937 is rated/needs 4m3/hr, with the smaller 831 at 3.3m3/hr.

As we all know MI's over rule anything else, even your calculations

The installation manual for the 937 that I'm looking at shows a max output of 37 Kw.

 

[gas4you]

MI's state that an 837/937 is rated/needs 4m3/hr, with the smaller 831 at 3.3m3/hr.

As we all know MI's over rule anything else, even your calculations

The installation manual for the 937 that I'm looking at shows a max output of 37 Kw.

If you follow the figures down you will see the 4m3/hr for G20 gas.

Would this be based on max heat input? I always get confused on these which is why I just stick to what the MI's state for gas consumption.

 

[doitall]

MI's state that an 837/937 is rated/needs 4m3/hr, with the smaller 831 at 3.3m3/hr.

As we all know MI's over rule anything else, even your calculations

The installation manual for the 937 that I'm looking at shows a max output of 37 Kw.

If you follow the figures down you will see the 4m3/hr for G20 gas.

Would this be based on max heat input? I always get confused on these which is why I just stick to what the MI's state for gas consumption.

Not in the manual I'm look at it don't

best I can do is.

Connection value (if necessary referred to storage tank charging/hot water preparation) at
15 °C and 1013 mbar
G20: 4.0
G31 : 2.94
G20 :m3/h
G31 : kg/h

 

[twgas]

I dont like to interfere, but DIA if you are looking at max output, as you say in your post, then I think you may just be undergassing.(if you typed output instead of input I'll shut up)

 

[BigBurner]

I would give BB an 75% chance of being the latest incarnation of DD/WS etc, if I were a gambling man.

Don't you would lose your money.

 

[JPC]

isnt the op just refering to 2 lengths of 28mm..then down to 22 i guess....
he did not mention "in parallel"

i think you have all misread the post, after tony's 1st reply mentions parallel pipes you've all gone down that route

2 lengths of 28mm (not parallel) could well be req, as mentioned depends on bends, elbows and other appliances connected

 

[Blasphemous]

Smurfy,

Do Sparks bicker like old women as much as Gas Fitters do?

 

[marsaday]

can i ask you about my installation. i had a corgi do it and the pressure test resulted in a 2bar drop i think. instead he uprated the gas coming from the meter because it was only just out. we fitted a Val 837 and put it in the loft. prob 15m from supply. to change half the gas feed to 28mm was not really needed. i was happy with what he did. is this so bad ?

 

[Blasphemous]

can i ask you about my installation. i had a corgi do it and the pressure test resulted in a 2bar drop i think. instead he uprated the gas coming from the meter because it was only just out. we fitted a Val 837 and put it in the loft. prob 15m from supply. to change half the gas feed to 28mm was not really needed. i was happy with what he did. is this so bad ?

marsaday,
Sorry to get all Big Brother bud but you need to post a new thread. This thread is smurfy125's.

 

[doitall]

I dont like to interfere, but DIA if you are looking at max output, as you say in your post, then I think you may just be undergassing.(if you typed output instead of input I'll shut up)

Yes I said output, because they don't give input in the manual,

Connection value (if necessary referred to storage tank charging/hot water preparation) at
15 °C and 1013 mbar
G20: 4.0
G31 : 2.94
G20 :m3/h
G31 : kg/h

I assumed they mean 4m³/hr, whatever the connection value means

In anycase the 12m x 28mm is good for 8m³/hr less any bends is more than large enough.