high point vent in flange 1

[God1knows]

Does anyone know if there's a standard arrangement for putting a high point vent into a #600 ANSI flange? I need it as part of a hydro test for a 300mm dia line.

If not, I was going to drill a hole near the top of the flange and weld some sore of weldolet that is ablt to be welded to the flat surface of the flange then attach the ball valve etc. Is there such a fitting?

Appreciate the help.

Dave

 

[europipe]

Drill a hole of approx. 5mm in the middle of the side of the flange with a chamber of a 7mm and weld apiece of pipe in it.
Just like an orifice flange.

Greetings

 

[zdas04]

I wouldn't do that on a bet. When I've needed to add a vent and there was a problem putting in a spool, I made a half spectacle blind )the open half) and drilled and tapped that. That way you don't compromise the design of the flange, but you get the vent you need. Orifice flanges are built to a different standard than regular RFWN flanges.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

 

[europipe]

Then you need more space

 

[zdas04]

If you can't spread a set of flanges at a high point enough to get a 3/4 inch thick plate and an extra gasket in then you have a real problem with the whole installation.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

 

[europipe]

God has to provide more info about this.

 

[TD2K]

You'd think God would already know the answer.

 

[moltenmetal]

zdas04 is right that it's preferable to put in a tapped ring than to mess with the flange- if it will fit. Depending on the size and run length of the lines, you might get away with that extra 7/8" of space between the flange faces or you might not. You might end up putting a hell of a lot of strain on that joint when you bolt it back up. Not every pair of flanges is designed to permit you to slip in a 3/4" spectacle blind at will.

If the fit-up is tight, a 1/4" hole drilled radially, parallel to the face of the flange dead centre between bolt holes (similar to an orifice tap) and terminated with a 1/4" NPT tapped into the flange so you can put a fitting on there could represent less risk of leakage later on than you'd get from straining the pipe to bolt up the joint.

BTW, the reason orifice flanges are designed to a different spec (i.e. the reason they're so thick) is to put the taps at the correct locations relative to the orifice plate to make the measurement, and to provide enough meat on either side of the tapping for the people that make their impulse lines out of 1/2" pipe rather than tubing.

 

[europipe]

I'm sorry, my English is not that well,
but I read He wanted a vent on a flange,
nor an upside down dripring after- or an elbolet on the elbow before the flange.
I don't know why He wants it on a flange, and I agree with others it's not the best practice.
God is far away, isn't He?

 

[maddocks]

Go with the bleed ring - we use them all the time. Alternately, switch the flange set out to a tapped meter flange and just rotate the holes to the vertical position. Drilling and tapping flanges is a fitting modification and that's not cool.