Foodservice Regulator FAQ

1. How does a regulator work?
2. Why and when do I need to use a regulator?
3. How can you tell if the regulator is for natural or propane gas? What are the differences?
4. What is the difference between adjustable and convertible regulators?
5. Are adjustable regulators available?
6. What are convertible regulators?
7. What is the spring adjustment?
8. Can I set the spring myself or do I need to order it with the spring already set?
9. How can outlet pressures of adjustable regulators be changed?
10. How can convertible regulators be changed from natural gas to LP or vice versa?
11. For which installations are different pressure (½ lb., 2 psi) most appropriate?
12. When do I need an R48 regulator and when do I need an R325 or R625 regulator? What is the difference between them?
13. How do I know what size I need?
14. What are vent limiters?
15. Are vent limiters available?
16. How can I tell which water column I need?
17. Are Dormont regulators CSA approved?
18. Where is the regulator attached?
19. How will I know the regulator has failed in the open position?

1. How does a regulator work?

Regulators reduce the pressure from a supply pressure to some other desired operating pressure. They do this independent of supply pressure and flow. So, whether a gas range is on low or on high, the pressure on the outlet side of the regulator will be the same.

2. Why and when do I need to use a regulator?

Gas is supplied to a home or building at pressures from ½ to 5 psi. Most appliances operate at much lower pressures, normally between 5 to 12 inches of water column. A regulator is required before all gas appliances to reduce the supply pressure to the operating pressure of the appliance.

3. How can you tell if the regulator is for natural or propane gas? What are the differences?

Natural gas and propane regulators are the same on the outside. The only way to identify each type is by the Dormont part number. The first letter, following the series number, designates the type of gas. N is for natural gas and P is for propane. The actual difference is in the spring setting. Propane requires a regulator with a higher spring force.

4. What is the difference between adjustable and convertible regulators?

Whether the term adjustable or convertible is used, the terms refer to controlling the outlet pressure of the regulator. Adjustable regulators can be set to any outlet pressure within the specified operating range. Convertible regulators offer two choices of outlet pressures.

5. Are adjustable regulators available?

All of the Dormont regulators are adjustable.

6. What are convertible regulators?

Convertible regulators allow the operator a quick change between LP and natural gas if necessary.

7. What is the spring adjustment?

Spring adjustment refers to how the outlet pressure of adjustable regulators is changed. Each type of spring provides a unique outlet pressure range.

8. Can I set the spring myself or do I need to order it with the spring already set?

If the specified outlet pressure range includes the desired outlet pressure, the spring can be adjusted to provide the required outlet pressure. A new spring is needed only if the desired pressure is outside the specified outlet pressure range.

9. How can outlet pressures of adjustable regulators be changed?

The outlet pressures of the adjustable regulators can be changed by removing the stem cap and adjusting the screw found inside. Turning the screw counter clockwise reduces the outlet pressure and turning it clockwise increases it.

WARNING: Adjusting the outlet pressure should only be done while monitoring the pressure with a manometer or other type of pressure gauge. Replace the stem cap when the adjustment is complete.

10. How can convertible regulators be changed from natural gas to LP or vice versa?

Remove the cap of the regulator and look for the round pin inserted in the bottom side of the cap. This pin should be installed with the larger round disk towards cap for natural gas operation and away from the cap for LP operation. This disk is used to compress the inner spring for LP applications. If the desired gas is different than the current setting, pull the pin out of the cap and insert the other end into the same hole in the cap. Finally, replace the cap on the top of the regulator and verify the correct outlet pressure.

11. For which installations are different pressure (½ lb., 2 psi) most appropriate?

Dormont offers regulators for ½ through 2 psi applications. It is important to note that these pressures refer to inlet (supply) pressures.

The R48 Series is specially designed for up to ½ psi installations. This regulator is available with either ½” NPT or ¾” NPT connections.

The R325 and R625 regulators can both be used in up to 2 psi applications. The R325 regulator is intended for ½” piping systems, and the R625 is used on ¾” systems.

12. When do I need an R48 regulator and when do I need an R325 or R625 regulator? What is the difference between them?

R48 regulators are used where low inlet pressure is present and low flow capacities are required. Typically, these regulators supply only one appliance.

The R325 and R625 regulators are generally used in applications with high inlet pressure and high flow. They can supply more than one appliance. In low-pressure applications where R48’s do not meet the flow requirements, the R325 or R625 could be used.

13. How do I know what size I need?

The first step is to identify the supply pressure, the required outlet pressure, the required flow capacity and the pipe size. Next, choose a Dormont regulator based on the supply pressure, outlet pressure and the pipe size. Finally, verify that the flow capacity is acceptable. If the flow capacity is not acceptable, try a larger regulator. Flow capacities, ranked from lowest to highest, are R48, R325 and R625.

14. What are vent limiters?

During normal operating conditions, vent limiters allow air to be drawn in and pushed out of the regulator as the diaphragm cycles due to outlet pressure changes. In the event of a diaphragm failure, the vent limiter restricts the leakage of gas to a low level.

15. Are vent limiters available?

Dormont regulators use two types of vent limiting methods. The R48 Series has a vent limiter built into the cover of the regulator. The red dust cap, seen from the outside, protects this orifice from dirt and other contamination.

The R325 and R625 regulators use a ball check vent limiting system. This method uses a ball check valve that allows air to enter and exit the regulator quickly. If the diaphragm fails, the ball check valve closes and the gas is routed through an orifice built into the ball check limiter. This device is a hex-shaped cap on the top of the regulator cover. It is used in applications that require the regulator to cycle frequently.

16. How can I tell which water column I need?

The appliance manufacturers specify the operating pressure range of the appliance. Select the regulator based on this pressure. If a preset regulator is not available, an adjustable regulator with the correct pressure range can be set to provide the required outlet pressure.

17. Are Dormont regulators CSA approved?

Yes, all Dormont regulators are CSA approved.

18. Where is the regulator attached?

The regulator is mounted in the gas line upstream of the appliance. Both the inlet and the outlet of the regulator contain female pipe threads that allow them to be easily installed in the gas line.

19. How will I know the regulator has failed in the open position?

The flame of the appliance will be dramatically higher than normal due to the increased pressure. If this occurs, turn off the appliance immediately.