Regulator Vent Positions

Field Topics are intended to provide useful information to the network of authorized LP-Gas and Anhydrous Ammonia distributors regarding the proper use of RegO® products.

Warning Bulletins covering many of the hazards involved are available from RegO for more detailed information. These bulletins can be found in our L-500, L-102 and NH3-102 catalogs. Neither the Field Topic or the Warning Bulletins are intended to conflict with federal, state, or local ordinances and/or regulations, which should be observed at all times. This information also is not intended to be a substitute for or to supplement any training in the safe handling and use of propane and related equipment, as required by any applicable law. By providing this material, ECI assumes no responsibility for providing any such training. Only individuals properly trained in the safe handling and use of propane and related equipment should be permitted to do so, and by providing this information, ECI does not assume responsibility for providing such training

For more information on LP Gas system requirements, refer to Liquefied Petroleum Gas Code (NFPA 58), National Fuel Gas Code (NFPA 54), National Propane Gas Association Safety Handbook, the RegO LP-Gas Serviceman’s Manual L-545, RegO catalogs L-500/L-102/NH3-102, ANSI K61.1 Safety Requirements for Storage and Handling of Anhydrous Ammonia, as well as any applicable local codes and ordinances.

Regulator Vent Positions

In general, regulators should be installed with the vent facing down or under a protective cover. It is a requirement of UL 144 and NFPA 58 2020 that regulators shall be designed to provide drainage of all condensation from the entire regulator bonnet cavity when the vent is directed vertically down.

It is important to order each regulator with the proper vent position specified.  This will ensure the user will be able to orientate the regulator properly to allow for condensate to drain out of the regulator body. First-Stage, High-Pressure and Integral Two-Stage regulators are supplied standard with the vent over the outlet. Second-Stage regulators standard order will have a vent over the inlet. Removing the bonnet screws and modifying the vent position in the field is not recommended and will void the RegO 10 Year Warranty. 

RegO regulators are constructed with a drain opening in the vent opening. The vent opening must be installed downwards to allow moisture to drain from the bonnet to prevent freezing.

To properly order a regulator with its vent in the correct position, the regulator must be referenced with the outlet facing downwards.  When specifying a regulator model, consider the following key which uses a clock as reference for vent position.

Example 1:
LV4403B4 An LV4403B4 comes standard with the vent over the inlet or 12 O’clock position


Example 2: LV4403TR
An LV4403TR comes standard with the vent over the outlet or 6 O’clock position.


Example 3: LV404B96
An LV404B96 comes standard with the vent over the outlet or 6 O’clock position.


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Field Topic Conductor :

​​Cody Reeves – LPG Tech. Services Manager

10+ years as a Propane Service Technician including installation and service of gas equipment.​​

State of CT Licensed Gas & Oil contractor.​​

Graduated from a Technical high school majoring in HVAC