Type of stone/gravel for Transformer secondary containment basin 1

[sparkview]

Hi folks,

We currently in the construction process of secondary containment basins for three 50MVA oil emersed transformers.
The project developer is currently planning to fill the basin with what seems to be limestones in the basins.
Can anyone recommend the type of stone that should be used and is there a standard that this can be related to?

In advance many thanks for any suggestion.

Jairo

 

[cranky108]

Our Civil engineer usually handles that, but I believe they use 1.5 inch crushed rock for all substation rock.

Smaller rock has loads of fines, and cars get stuck in it.

 

[dik]

I've done several transformer yards and usually use clean crush 'Fire Quenching Stone' to the following (from my Project Notes)

FIRE QUENCHING STONE (ALBARRIE CONTAINMENT SYSTEM)
CLEAN, WASHED, ANGULAR CRUSHER RUN LIMESTONE CONSISTING OF HARD DURABLE PARTICLES FREE FROM SILT, CLAY AND SILT LUMPS, FRIABLE MATERIALS, CEMENTATION, SOLUBLE MATERIALS, FROZEN MATERIALS AND ORGANIC MATTER. VOID RATIO 45% MIN

FILL SHALL CONFORM TO:
SIEVE SIZE (ASTM) PERCENT PASSING
3 100
1-1/2 0-2
3/4 0-1


FIRE QUENCHING STONE (ALBARRIE CONTAINMENT SYSTEM)
CLEAN, WASHED, ANGULAR CRUSHER RUN LIMESTONE CONSISTING OF HARD DURABLE PARTICLES FREE FROM SILT, CLAY AND SILT LUMPS, FRIABLE MATERIALS, CEMENTATION, SOLUBLE MATERIALS, FROZEN MATERIALS AND ORGANIC MATTER. VOID RATIO 45% MIN

FILL SHALL CONFORM TO:
SIEVE SIZE (ASTM) PERCENT PASSING
75 100
37.5 0-2
19 0-1


FIRE QUENCHING STONE (ALBARRIE CONTAINMENT SYSTEM)
CLEAN, WASHED, ANGULAR CRUSHER RUN LIMESTONE CONSISTING OF HARD DURABLE PARTICLES FREE FROM SILT, CLAY AND SILT LUMPS, FRIABLE MATERIALS, CEMENTATION, SOLUBLE MATERIALS, FROZEN MATERIALS AND ORGANIC MATTER. VOID RATIO 45% MIN

FILL SHALL CONFORM TO:
SIEVE SIZE (CAN METRIC) PERCENT PASSING
75000 100
40000 0-2
20000 0-1

This is used with their product Sorbweb... a material that gels when exposed to transformer oil. There is a 'window' in the entrapment basin that allows rainwater to pass, but chemically seals to keep oil from passing... It's an excellent product and have used it about a dozen times.


Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik