8 replies to this topic

[ichemco]

it would be highly appreciated if inform me about the limitations and restrictions of fuel gas piping network design. I'd like to know that if it is permissible to pocket the fuel gas piping network or not. From my own point of view in gathering section the piping route must not be pocketted because the gas may contain liquid droplets(carry over) to some extent, but at the distribution side because of existance of superheater at downstram of mixing drum, pocketing the piping system would not be any matter of concern.

[fallah]

it would be highly appreciated if inform me about the limitations and restrictions of fuel gas piping network design. I'd like to know that if it is permissible to pocket the fuel gas piping network or not. From my own point of view in gathering section the piping route must not be pocketted because the gas may contain liquid droplets(carry over) to some extent, but at the distribution side because of existance of superheater at downstram of mixing drum, pocketing the piping system would not be any matter of concern.

What do you mean by "superheater" in distribution side?

As far as i know, in fuel gas distribution network,at least the header shouldn't be pocketed.

[ichemco]

it would be highly appreciated if inform me about the limitations and restrictions of fuel gas piping network design. I'd like to know that if it is permissible to pocket the fuel gas piping network or not. From my own point of view in gathering section the piping route must not be pocketted because the gas may contain liquid droplets(carry over) to some extent, but at the distribution side because of existance of superheater at downstram of mixing drum, pocketing the piping system would not be any matter of concern.

What do you mean by "superheater" in distribution side?

As far as i know, in fuel gas distribution network,at least the header shouldn't be pocketed.

[djack77494]

Once you get downstream of the superheater for a gaseous fuel, then you should not have to worry about liquids. Therefore avoiding pockets would not be a requirement. (But one cautionary note: Systems I've seen like this have the burners not very far from the superheaters.)

[ichemco]

it would be highly appreciated if inform me about the limitations and restrictions of fuel gas piping network design. I'd like to know that if it is permissible to pocket the fuel gas piping network or not. From my own point of view in gathering section the piping route must not be pocketted because the gas may contain liquid droplets(carry over) to some extent, but at the distribution side because of existance of superheater at downstram of mixing drum, pocketing the piping system would not be any matter of concern.

What do you mean by "superheater" in distribution side?

As far as i know, in fuel gas distribution network,at least the header shouldn't be pocketed.

Superheaters are normally used in fuel gas systems which contains considerable amounts of C4 or heavier components. They may use after LPG vaporizers or fuel gas mixing drums.Generaly they are sized to maintain the temperature of the fuel gas 100 °F above its dew point.

[ashetty]

Once you get downstream of the superheater for a gaseous fuel, then you should not have to worry about liquids. Therefore avoiding pockets would not be a requirement. (But one cautionary note: Systems I've seen like this have the burners not very far from the superheaters.)

Hello djack,

Dont we have to take into consideration the distance of the fuel gas system from the users and also the lowest ambient temperature?

Thanks

[Qalander (Chem)]

Once you get downstream of the superheater for a gaseous fuel, then you should not have to worry about liquids. Therefore avoiding pockets would not be a requirement. (But one cautionary note: Systems I've seen like this have the burners not very far from the superheaters.)

Hello djack,

Dont we have to take into consideration the distance of the fuel gas system from the users and also the lowest ambient temperature?

Thanks

Dears,

Although this may look stupid on my part;I am really unable make out what is really meant by'pockets' by the OP.Either OP or someone else throw light please!
As regards fuel gases consisting mainly LPG like components do require these stream piping thoroughly insulated(externally) and occasionally steam traced as per the butane or any heavier component's %age variation(s) and ambient temperatures encountered.

Since it it imperative to maintain average fuel gas molecular weight(s) for burner's efficiency ensuring smooth heat input& safer combustions avoiding possible explosion risks inside fire boxes;everyone resorts to LPG like fuel gas components vaporisation and keeping in gaseous(preferably well mixed) state.
Hope this is helpful indeed!

[ashetty]

Once you get downstream of the superheater for a gaseous fuel, then you should not have to worry about liquids. Therefore avoiding pockets would not be a requirement. (But one cautionary note: Systems I've seen like this have the burners not very far from the superheaters.)

Hello djack,

Dont we have to take into consideration the distance of the fuel gas system from the users and also the lowest ambient temperature?

Thanks

Dears,

Although this may look stupid on my part;I am really unable make out what is really meant by'pockets' by the OP.Either OP or someone else throw light please!
As regards fuel gases consisting mainly LPG like components do require these stream piping thoroughly insulated(externally) and occasionally steam traced as per the butane or any heavier component's %age variation(s) and ambient temperatures encountered.

Since it it imperative to maintain average fuel gas molecular weight(s) for burner's efficiency ensuring smooth heat input& safer combustions avoiding possible explosion risks inside fire boxes;everyone resorts to LPG like fuel gas components vaporisation and keeping in gaseous(preferably well mixed) state.
Hope this is helpful indeed!

Hello Qalander,

The term " no pockets" means that the piping should be run to prevent pockets.
Sometimes liquid or condensate collect at low points in the piping, for two phase lines.Then a change in velocity of the gas phase might cause a slug of liquid etc.The piping layout should avoid these low points for 2 phase lines or where there is possibility of liquid formation in gas phase lines.

Best Regards

[Qalander (Chem)]

Once you get downstream of the superheater for a gaseous fuel, then you should not have to worry about liquids. Therefore avoiding pockets would not be a requirement. (But one cautionary note: Systems I've seen like this have the burners not very far from the superheaters.)

Hello djack,

Dont we have to take into consideration the distance of the fuel gas system from the users and also the lowest ambient temperature?

Thanks

Dears,

Although this may look stupid on my part;I am really unable make out what is really meant by'pockets' by the OP.Either OP or someone else throw light please!
As regards fuel gases consisting mainly LPG like components do require these stream piping thoroughly insulated(externally) and occasionally steam traced as per the butane or any heavier component's %age variation(s) and ambient temperatures encountered.

Since it it imperative to maintain average fuel gas molecular weight(s) for burner's efficiency ensuring smooth heat input& safer combustions avoiding possible explosion risks inside fire boxes;everyone resorts to LPG like fuel gas components vaporisation and keeping in gaseous(preferably well mixed) state.
Hope this is helpful indeed!

Hello Qalander,

The term " no pockets" means that the piping should be run to prevent pockets.
Sometimes liquid or condensate collect at low points in the piping, for two phase lines.Then a change in velocity of the gas phase might cause a slug of liquid etc.The piping layout should avoid these low points for 2 phase lines or where there is possibility of liquid formation in gas phase lines.

Best Regards

Thanks for this important clarification;somehow I always thought to use the word "liquid slugs" or "condensed liquids entrainment" causing problems.

Principally we are almost on the same lines and motive was also same, I understand.

i.e to avoid any sudden condensed liquid components entry with higher molecular weights; thus Possible sudden heat input (spikes) and even consequentially explosions risks get generated from unchecked operation.

Hope this& my previous post contents help.