Gas volume

[barronbathrooms]

I have won the contract for the installation of 3 central heating systems in a doctors surgery which spans across 3 separate buildings. All 3 boilers are to be fed from a u16 meter I have done all my gas calculation and will have 0.055272 meters cubed of gas in the system. On a domestic ticket I can only test and purge up-to 0.035 meters cubed. My question is can I split the pipe work by isolation valves and test separately so I can sign off the job with my domestic
ticket!

 

[kirkgas]

it is perfectly acceptable for you to get a commercial guy to fit seperate iso valves and test points and test the whole installation, then for you to work from each iso, as long as each leg you work on doesnt have an IV of more than 0.035m3, and remember if each leag has IV above 0.02m3 you need a different purge procedure

 

[gasmarc]

well I live and learn, I thought it was 60kw and below that was classed as domestic

 

[barronbathrooms]

Thanks for replies spoke to gas safe and my mate today he is going on my registration and will sign job off for me happy days!

 

[sparra1100]

well I live and learn, I thought it was 60kw and below that was classed as domestic

70 kw gasmarc plus think its u16 meter and below 35mm pipe

 

[SimonJohns]

well I live and learn, I thought it was 60kw and below that was classed as domestic

45kw per appliance. 70kw max install

 

[Roger Welton]

Or for 'comercial intent'

think overhead radiants and the like

 

[gasmarc]

45kw max appliance I dont think that is correct and if it is I think there is a few of us that are working out of scope :book:

 

[mike_s]

it's 70kw, no bigger than a u16, 35mm pipe and 0.035 installation volume. I've worked on a Buderus boiler in a hotel with a heat input of exactly 70kw. Spoke to Buderus and Gas Safe before I did and it was fine for me to work on with just my domestic tickets. Same goes for their Andrews water heaters as they were only 12kw even though a commercial design.

 

[kirkgas]

well I live and learn, I thought it was 60kw and below that was classed as domestic

70kw net now

 

[gasmarc]

Good stuff just got a call to look at a keston 55 tomorrow:frown2:

 

[adam84]

The 70kw size limit is a very misleading way of defining the scope of domestic/commercial work because boilers in the UK are manufactured to two seperate standards, BS6798 refers to domestic boilers and BS6644 refers to commercial boilers. This means that an engineer holding CCN1 and CEN1 could not install a 30kw boiler made to BS6644 but could install a 70kw boiler to BS6798, so to install the 30kw boiler he would need to acquire COCN1, ICPN1, TPCP1A and ICAE1/CIGA1, these cover commercial core safety, installation and first fix of commercial pipework, testing and purging of low pressure commercial pipe work not exceeding 1m2 and 21mbar operating pressure and first fix/ install commercial indirect fired appliances respectively.

 

[mike_s]

not doubting you but are you sure you need the commercial pipework and testing quals just because the boiler is commercial but what if the pipework and meter is not?

Exactly why I am doing just my codc1, comcat 1 and 3 in 2 weeks time as where I am working does not have commercial size meter or pipework and I've sought advice from gas safe on that

Regarding the commercial design boiler, sounds about right, I'll look out for that in the future. the 70kw boiler I've worked on, Buderus say they make it that so people can work on it with domestic tickets so I assume it is to bs6798 and not the commercial bs6644.

 

[bennygas]

Has anyone looked at the note in bold on p137 of EGS 5th Ed. Seems to advocate the sectioning principle mentioned.

 

[bennygas]

what's boyles law/ideal gas eqn got to do with anything? I'm guessing you're saying that the process is isothermic - but why're you testing at about 1/5th atmospheric pressure? what's this for? transpose the formulae to make either v1 or v2 the subject and the answer should drop out.