gas pressure regulators

Eric Lanser

One of my customers is having a problem with gas pressure regulators freezing up on new 10 ton natural gas fired HVAC packaged roof top units. The gas inlet pressure is 28" and the regulators are set to 7.5". The Regulators are installed outside on the roof of this one story industrial complex. They are mounted horizontal and are within the BTUH range of the roof top equipment. They operate fine until the outside air temp drops into the 20's.


Any Help would be greatly appriciated.

Thanks Eric

Unknown

Put a drip leg on the riser to the roof

make it about 18" long and fill it with "Methanol" it will mix with the gas and keep it from freezing. The methanol will not harm the equipment.

Eric Lanser

> make it about 18" long and fill it with

> "Methanol" it will mix with the gas and keep it

> from freezing. The methanol will not harm the

> equipment.



Tim

Thank you very much for taking the time to help me with my problem. I will try the drip leg this week.

Eric

Donny

freezing regulators

always install 2 street 90*s or a return bend on the relief port of any regulator exposed to weather, or risk the possibility of water/ ice forming inside the regulator

Ed_26

freezing regs

Are these regs rated for outside use? As previously asked, are the vents terminated in the 'down' position? If the reg orifice is too small, the velocity of the gas passing thru will cause frost - have you checked the mfg. specs?