5 replies to this topic

[iplan]

I would like to know the maximum allowable gas velocity in pipelines . is there any guideline on this. For instance, API RP 14E - guidelines can anybody throw some light on this.

1. There is a limit specified as 60 ft/sec for noise related issues but if the noise is taken cae then is higher velocities accepted? The gas to be transported is hydrogen.

2. what is the limit on the velocity from erosion point of view considering the gas may be wet or dry.

many thanks
iplan

[Qalander (Chem)]

Dear iplan Hello/Good afternoon,

Referring point#2 only
definitely if particulates are carried along at higher velocities; erosin issues bound to come in action also liquid droplets of any kind may have similar effect;I assume.

Situation may be more sever,if temperatures are supportive for sustained particulates/entrained liquid droplets carriage.

Hope this is someway helpful.

Regards
Qalander

[Randy Smith]

Iplan:

The limit would essentially be sonic velocity. The practical answer depends on how much pressure drop in the system, and the extent of the noise level you are willing to accept. As to the methodology depicted in API RP14E for calculating erosional velocity, the Recemmended Practice allows for a wide range of fluid properties, based on an empirical constant dictated either by your experience, or best guess as to how "corrosive" and "erosive" you expect the fluid to be.

Obviously, if you expect suspended solids, such as sand and sediment, then a prudent number may be 75, or as low as 50. API recognized the infinite variety of fluid compositions by allowing the designer to arbitrarily select a "fudge" factor.

[ankur2061]

Hi,

Refer Section 6.3 (6.3.2) of Norsok P-001 Rev. 5 for maximum velocities in gas lines. This standard can be downloaded for free. You can use the following link to look for the free download:

http://www.standard....er.exe?id=13264

Come back with your response whether things are clear or not.

Regards,
Ankur.

[S. Biswas]

1) If noise is taken care separately, the maximum velocity for gas flow that can be allowed is 80% of sonic velocity, or [200/sqrt (density, lb/ft3)] ft/s, which ever is lower.

2) This depends on service, a material specialist can answer better.

S.Biswas

[iplan]

Hi,

My sincere thanks. The download that Ankur sent specifies 60 m/sec or 175*(1/density)^0.43 whichever is lower. I thought the limit is 60 ft/sec. Looks like the numbers are dependent on experience. looking to know further on this subject.

Thanks again,
iplan.