metaldad
Well-known member
R13 is not a common refrigerant, low temp refrigerant usually used for flash freezing.
Back in the day (late 70's early 80's)I recall people using R13 (or a product called that) as a pre flush. This was well before refrigerants were considered hazardous to the environment.
Most low temp refrigerant systems that used R12 turned to R134a
i believe you must be thinking of r11.
yes, r12 systems have been converted to 134. r12 was a medium temp gas.
r502 was the standard for low temp before the montreal protocol money grab