Capping off redundant pipework question. Discussion Thread
Hi all.
I done some work for someone a few years ago and I've been getting paranoid that things haven't been done the right way.
I capped off a gas cooker supply that was no longer in use, left the redundant pipework capped off at the appliance isolation valve in the kitchen.
I'm getting paranoid that if someone later down the line for some reason, was to drop the pressure in all of the pipework, say during a boiler service or for a boiler appliance shut off valve change over, such that when the pressure in all of the pipework is dropped to atmospheric pressure, this will also include the branch that went into the kitchen to feed the old gas cooker. When the engineer then goes to purge air to gas again for what he might believe is the only branch of pipework in the house (meter to boiler) that he doesn't realise there is another branch going to an old gas cooker, and then the new gas mixes with the air in the gas cooker branch and creates an explosive mixture in the pipework?
Now I know there must be loads of people all over the country who have just capped the pipework at the appliance shut off valve when removing an old appliance, and they will not have capped at the tee in the main branch since not always feasible and is it even required in a small domestic system? With an IV of less than <0.035m3
The branch of redundant pipework I'm talking about is probably no more than 0.003m3 (15mm copper of no more than 20meters run max)
My training booklet from college IGE UP 1B edition 3(small installations) doesn't say anywhere that redundant pipework should be left full of air, only that the appliance which is not commissioned must be disconnected from gas supply and sealed with appropriate fitting.
My training booklet for IGE UP 1A (commercial installations of up to IV 1m3) does state that "where a section of pipework is to be removed permanently, the pipe ends onto which it had been originally connected shall be isolated physically by spading or blanking off...
Read more
Capping off redundant pipework question. for the original thread on Plumbers Forums
Hi all.
I done some work for someone a few years ago and I've been getting paranoid that things haven't been done the right way.
I capped off a gas cooker supply that was no longer in use, left the redundant pipework capped off at the appliance isolation valve in the kitchen.
I'm getting paranoid that if someone later down the line for some reason, was to drop the pressure in all of the pipework, say during a boiler service or for a boiler appliance shut off valve change over, such that when the pressure in all of the pipework is dropped to atmospheric pressure, this will also include the branch that went into the kitchen to feed the old gas cooker. When the engineer then goes to purge air to gas again for what he might believe is the only branch of pipework in the house (meter to boiler) that he doesn't realise there is another branch going to an old gas cooker, and then the new gas mixes with the air in the gas cooker branch and creates an explosive mixture in the pipework?
Now I know there must be loads of people all over the country who have just capped the pipework at the appliance shut off valve when removing an old appliance, and they will not have capped at the tee in the main branch since not always feasible and is it even required in a small domestic system? With an IV of less than <0.035m3
The branch of redundant pipework I'm talking about is probably no more than 0.003m3 (15mm copper of no more than 20meters run max)
My training booklet from college IGE UP 1B edition 3(small installations) doesn't say anywhere that redundant pipework should be left full of air, only that the appliance which is not commissioned must be disconnected from gas supply and sealed with appropriate fitting.
My training booklet for IGE UP 1A (commercial installations of up to IV 1m3) does state that "where a section of pipework is to be removed permanently, the pipe ends onto which it had been originally connected shall be isolated physically by spading or blanking off...
Read more
Capping off redundant pipework question. for the original thread on Plumbers Forums
