Dec 28, 2018 - 12:18 PM
The C6121 is a series of regulators that was made by Marshall Gas Controls. It is a high pressure regulator, and depending on the complete model number, it could have an outlet pressure anywhere from 5 PSIG to 100 PSIG. If it was used on a fifth wheel RV for the far side tank, it probably has a 30 PSIG fixed outlet pressure setting, to feed the changeover regulator on the near side. As an educated guess, the best replacement for that would be MEGR-6121-30. However, to make a firm recommendation, I would need to know more details about where it’s being used, required pressures, etc.
MEGR-230 is a low pressure regulator, with 11”WC (0.4 PSIG) outlet pressure. It is only intended for use with outdoor low pressure appliances, like grills, patio heaters, etc. It would definitely not be a replacement for a C6121.