Propane tank anchoring

[Larryhd2]

I'm engineering the anchorage and footing for a 1000gal propane tank... it's for a school and it's used to serve a generator that serves pumps for fire suppression in case of power outage, so it's Risk Category III.

The steel tank is 42"dia, 16' long and lays horizontal supported on 4 "feet" welded on the tank. The feet are then bearing on and anchored to the slab/footing.

I've looked through all of the design parameters in ASCE 7, but I'm not engineering the tank, just the anchoring and foundation. Is there a simple factor like some percentage of Sds I can apply to design the anchoring and footings?

 

[Rabbit12]

Calculate the seismic base shear using Chapter 15 of ASCE 7. Anchor forces should be pretty simple from that point forward.

 

[Larryhd2]

Calculate the seismic base shear using Chapter 15 of ASCE 7. Anchor forces should be pretty simple from that point forward.

Yeah, I looked that over but I'm seeing all the slashing factors and whatnot.... there is probably a rigid mass consideration I'm not seeing.

 

[r6155]

Best post in the following Forum

1. Boiler and Pressure Vessel engineering

 

[HTURKAK]

This is rigid non-building structure having a fundamental period less than or equal to 0.06 s. Pls look clause 15.4.2

15.4.2 Rigid Nonbuilding Structures Nonbuilding structures
that have a fundamental period, T, less than 0.06 s, including
their anchorages, shall be designed for the lateral force obtained
from the following:
V = 0.30SDSWIe

The force shall be applied at the centroid of the tank.

 

[Larryhd2]

This is rigid non-building structure having a fundamental period less than or equal to 0.06 s. Pls look clause 15.4.2

15.4.2 Rigid Nonbuilding Structures Nonbuilding structures
that have a fundamental period, T, less than 0.06 s, including
their anchorages, shall be designed for the lateral force obtained
from the following:
V = 0.30SDSWIe

The force shall be applied at the centroid of the tank.

I figured it was in there somewhere... 15.7.6.1a also points to this.... thank you!

 

[r6155]

Wrong design. Saddle support is used.
You can see standard design and avoid calculation in
PIP (Process Industry Practice) VEFV 1105.

 

[Larryhd2]

Wrong design. Saddle support is used.
You can see standard design and avoid calculation in
PIP (Process Industry Practice) VEFV 1105.

That looks to be a good document for the tank itself. I didn't see anything for anchoring other than bolt diameter, and there was nothing for foundations.

Also, since this is for feeding a generator for fire suppression, the importance factor for the anchoring is 1.5, so it may not have applied anyhow.

Thanks for the response though, I do appreciate you taking the time to respond.

 

[r6155]

See PIP STE 05121 Anchor Bolt Design Guide.

 

[HTURKAK]

Wrong design. Saddle support is used.
You can see standard design and avoid calculation in
PIP (Process Industry Practice) VEFV 1105.

What is wrong ? Can you explain and be more specific?
If the horizontal vessel supported on concrete with short legs or saddle on short/rigid piers, it is RIGID NON-BUILDING STRUCTURE and the
seismic lateral force obtained with the equation V = 0.30SDSWIe.

 

[r6155]

This is a little equipment (not a tall tower), using PIP standard drawing for saddle support is enough without any calculation.
Be practical. Why complicate?

 

[Rabbit12]

This is a little equipment (not a tall tower), using PIP standard drawing for saddle support is enough without any calculation.
Be practical. Why complicate?

Generally curious, does the PIP provide anchor diameter, grade and embedment into concrete?

Some places such as CA aren't likely to allow you to just reference a PIP standard and will require calculations.