Nitrile Terminology ST-2 & BT-3

[jfielddeltadesign]

I am looking for standards that have been specified for a
-60C environment Nitrile BUNA-N Application

Does anyone know what "ST-2" and "BT-3" mean in the context shown below?

VENDOR P/N: XXXXXX - CP283-1 (LOW TEMP NITRILE)
DIAPHRAGM, DF, LOW TEMP
***MUST CONFORM TO ST-2 AND BT-3***

 

[Dtuck]

See the people from Marshbellofram.com
diaphragm division.