SiO2

<12%

Fe2O3

<0.5%

Alkaline matter

<2.5%

Density

2.6 g/cm3

Hardness

7 M

Water absorption

<0.2%

Rupture  strength

>1300kg/cm2

Gas tightness

Kept for ten minutes at negative pressure of 1.3Kpa.

The pressure drop is less than 0.3Kpa.

Heat tolerance

Insert the pipe into the furnace at a depth of 20mm.

Heat to 1600ºC and maintain for 30 minutes.

Alkali tolerance

In the Na2CO3 solution of 2N concentration,

boil for 15 hours with the weight loss not greater than 20mg/dm2.

Volume resistance

>2*10(5) Ω·cm/1300ºC

Breakdown voltage

18kv/cm

Expansion coefficient

5*10(-8)

Temperature for use

Long-term: 1400ºC  Short-term: 1600ºC

Chill and abrupt heat

1300ºC~room temperature not cracking thrice.