where to buy iron fittings for gas???

[tamz]

purge commercial pipes with air??
5-15% explosive ratio ?
isnt that dodgy?

No really if you have a compressor (a real one).

 

[tamz]

oooo hemp! no no no! Anything up to 1" with any pressure can be screwed or welded, Up to 2" and 500mbar can be screwed, anything over 2" or over 500mbar welded only.

I've just corrected Tamz! I'm going to that special corner of hell reserved for people that dare do that!

I was taught to use a bit hemp on gas joints over 2". I never doubted it as it came from older smarter heads than me but that is out the window now anyway as everything over 2 is welded has been for the past 7 or 8 years
Point taken tho :wink: :lol:

 

[Dotty]

No really if you have a compressor (a real one).

I agree, I would prefer to use O2 free nitrogen but I don't always have a large enough bottle with me. But I always have the compressor!

 

[Scott_D]

It's a pain when you get soloinid valves etc that are bigger than 2" with screwed connections

 

[Masood]

I agree, I would prefer to use O2 free nitrogen but I don't always have a large enough bottle with me. But I always have the compressor!

Out of curiosity (I'm not commercial!) what are you pumping through with the compressor? Just air? I thought the whole point of commercial purging was that it had to be an inert gas because of the sheer volume of pipework and appliances - it's too big a risk if that amount of gas/air mixture hits the explosive ratio. Or have I totally misunderstood? I've not commercial gas training, this is just me figuring it out logically, by the way, so I am happy to be corrected!

 

[Dotty]

Out of curiosity (I'm not commercial!) what are you pumping through with the compressor? Just air? I thought the whole point of commercial purging was that it had to be an inert gas because of the sheer volume of pipework and appliances - it's too big a risk if that amount of gas/air mixture hits the explosive ratio. Or have I totally misunderstood? I've not commercial gas training, this is just me figuring it out logically, by the way, so I am happy to be corrected!

No worries Mas, easiest way to learn is to ask.

It is just air but the difference is you're pumping it through at a greater volume and velocity minimising the risk of the explosive ratio being reached. My compressor is a 24ltr one and I usually leave it connected for about 5-10 minutes.

My purge stack is, or was (I have to make a new one, my old one was lent to a boy at work and is now in Scotland!), a 3.5m length of 1" pipe, welded at the bottom to an 8" blank flange with reinforcing. An equal tee 400mm up, a sample point (1"x1"x1/2" tee with union and lever valve) at 1.2m, and an elbow into a short stub cut off at 45deg to prevent rain ingress. It's in two pieces, joined in the middle with a 1" union.

Basically I connect my purge hose to it, compressor at the other end and let fly!

 

[mutley racers]

No worries Mas, easiest way to learn is to ask.

It is just air but the difference is you're pumping it through at a greater volume and velocity minimising the risk of the explosive ratio being reached. My compressor is a 24ltr one and I usually leave it connected for about 5-10 minutes.

My purge stack is, or was (I have to make a new one, my old one was lent to a boy at work and is now in Scotland!), a 3.5m length of 1" pipe, welded at the bottom to an 8" blank flange with reinforcing. An equal tee 400mm up, a sample point (1"x1"x1/2" tee with union and lever valve) at 1.2m, and an elbow into a short stub cut off at 45deg to prevent rain ingress. It's in two pieces, joined in the middle with a 1" union.

Basically I connect my purge hose to it, compressor at the other end and let fly!

And if the meter does not have a purge point on it? What would you do

 

[SimonJohns]

And if the meter does not have a purge point on it? What would you do

Drill a hole in the pipe close to the meter

Remove the meter

Many options

 

[mutley racers]

Drill a hole in the pipe close to the meter

Remove the meter

Remove the meter, I think we suggested this option to him but have did no have fittings to connect.

Suggested cutting into the 3 inch but he said if we get spark then that is problem. What ever we suggested, it was a problem

 

[SimonJohns]

Drill a hole in the pipe close to the meter

Remove the meter

Remove the meter, I think we suggested this option to him but have did no have fittings to connect.

Suggested cutting into the 3 inch but he said if we get spark then that is problem. What ever we suggested, it was a problem

I wouldn't like to suggest the way I would drill the pipe then.

I read through some of this post. And "picking up a 28mm pipe" somewhere in the system to purge screams out a dangerous engineer to me

Surely even to a muggle it's obvious that you have to purge from the start and vent at the end. Not from one branch to another. There will be dead legs

Atleast the op didnt hurt anyone

 

[mutley racers]

No, re read the post. We ended up taking a branch off a 28mm supply from kitchen which had a stopcock. So no need to purge. Just put a test point after stopcock and carry on from there.

Sorry if my post is unclear

 

[mutley racers]

Hehe, a muggle, whats one of those then?

 

[SimonJohns]

No, re read the post. We ended up taking a branch off a 28mm supply from kitchen which had a stopcock. So no need to purge. Just put a test point after stopcock and carry on from there.

Sorry if my post is unclear

My appologies. I read it as that's where you put your purge on

 

[SimonJohns]

Hehe, a muggle, whats one of those then?

Harry potter

 

[Dotty]

Strictly speaking HP wasn't a muggle but I love the term for non gsr's!

That make trainees mudbloods?

 

[mutley racers]

Harry potter hey, never watched it. Obviously you guys have all got kids

 

[lame plumber]

so is croppie one of those goblin bankers then?

 

[Ermintrude]

Wild card here, does any one know how to create new thread on tap talk?

 

[SimonJohns]

Wild card here, does any one know how to create new thread on tap talk?

Top right corner

 

[SimonJohns]

Strictly speaking HP wasn't a muggle but I love the term for non gsr's!

That make trainees mudbloods?

Yes lol

 

[hammers4spanner]

Drill a hole in the pipe close to the meter

Remove the meter

Many options

to you this may sound idiocy

drill a hole then what??? ( presume hole drilled in pipe )

 

[SimonJohns]

Purge the gas out. Inject air or nitrogen

 

[Masood]

Purge the gas out. Inject air or nitrogen

Then presumably tap a thread into the hole and install a nipple/purge point?

 

[SimonJohns]

Then presumably tap a thread into the hole and install a nipple/purge point?

No. Just offer a pipe up. Get as best seal as possible with a rag or damp towel. And blow it out

Tapping the hole will create heat and there is still gas in the area your working in. Blowing it out ASAP is much safer

 

[hammers4spanner]

Bit confused here ,

right you drill a hole out,put a rag to it and blast through with air to get a compressor ,

then i presume tap a thread in after purging to seal the hole you have drilled???