5 replies to this topic

[Afshin445]

Dear Forume Experts,

I am working in a project which scope is to design a new cylindical storage tank instead of existing concrete tank which both new/existing tanks are supplied by N2 blanketing.

Existing tank has two type of protection ssytem, first is Breather Valve for protection of tank agianst any malfunction in inbreathing/outbreathing regulator valves(PRV's) and second is relief valve for protection of tank against fire.

Following is existing tank design data:

Type = Rectangular Concrete
Length = 38.6 m , Width = 10.6 m, Height =2.33 m
Design Pressure = 50 mbarg
Design Temp. = -1/50°C
Breather Valve Set Pressure = 40 / 6 (VAC) mbarg (Control Valve Failure)
Relief Valve Set Pressure = 40 mbarg (Fire Case)

The existing Relief Valve is Large,weight loaded emergency vent type same as sketch shown in figure C.3, Annex C of API-2000, 6th Ed,2009.In Fgure C.5 of Annex C the overpressure for this type of venting device shown is around 80% which mean Relief Pressure(when relief valve is fully open) is about 72 mbarg which is above tank design pressure(50 mbarg).

1th question: How this type of RV can protect the tank during Fire Case with Relief Pres.>Design Pres.?

2nd question: Can I use the same protection philosphy for new cylindrecal tank.That means breather valve for PRV failure and relief valve for Fire Case.

3rd question: How I can find the required number and size for wight loaded emergency vent?

The new tank design condition should be as below:

Type: Cone Roof
Dia.= 15 m , Heigh =10 m
Design Pressure = 56 / 8.5 (VAC) mbarg
Design Temp. = 0/50 °C

I am waitng to hearing from you soon.

Best Regards
Afshin

[fallah]

Afshin,

Please avoid double posting. You already submitted this query in relief devices forum.

Fallah

[fallah]

Afshin,

By using "Delete" option in the bottom of your post you can easily remove the repeated post.

Fallah

[Afshin445]

Afshin,

By using "Delete" option in the bottom of your post you can easily remove the repeated post.

Fallah

Fallah,

There is no "Delete" option in bottom of first post. This is only valid for later post.

Afshin

[fallah]

Afshin,

I am surprised! If you log in the site, at the bottom of each post of yours there are these options: Report Edit Delete

Please try to find...

Fallah

[Afshin445]

Afshin,

I am surprised! If you log in the site, at the bottom of each post of yours there are these options: Report Edit Delete

Please try to find...

Fallah

Fallah,

I am log in for sure.But there is no any "Delete" option for first post.I just can delete my later posts.
Maybe forume admin can help me in this regards.

Afshin