Pressure Regulators: Operation and Handling

The safest way to reduce cylinder pressure is through a pressure reduction regulator. Review the following information before using your pressure reduction regulator. Scott offers over 40 regulator series with more than 120 different pressure ranges to meet the needs of all your applications.

1. Inspection

Be certain that the materials of a pressure regulator are chemically compatible with the intended gas service before installation. Inspect the gas regulator for the proper valve inlet connection and note the ranges of the pressure gauges. Also examine the physical condition of the regulator including its threads and fittings. Remove any dust or dirt from the gas regulator or cylinder valve with a clean cloth. Do not install a gas regulator on a cylinder containing oxygen or another oxidant if grease or oil is present on the valve. Such combustible substances in contact with an oxidant can be explosive. Initiate procedures to have the equipment properly cleaned and identify the equipment to prevent usage.

2. Installing a Gas Regulator

The gas regulator should be securely installed on the cylinder valve using the proper wrench and without forcing the connection. Do not use pipe dope, pipe thread or PTFE tape on valve connections and never use valve connections that leak. Adapters from one valve connection to another valve are not to be used to connect equipment to a high-pressure cylinder. The gas regulator adjusting knob should be turned in the full counterclockwise or closed direction. Most Scott regulators are equipped with a needle valve in the regulator output or delivery port. This needle valve should be closed by turning its adjustment knob in the full clockwise direction. The downstream equipment connection can then be made to the gas regulator output needle valve.

3. Operating a Regulator

►The operator, protected by safety glasses, should stand to the side of the gas cylinder opposite the regulator and slowly open the cylinder valve until the high-pressure gauge indicates the full cylinder pressure.

►The regulator output needle valve can be opened after it is certain that all downstream equipment is rated for pressures above the maximum regulator outlet pressure.

►Open the gas regulator by turning its adjustment knob clockwise until the desired output pressure is indicated on the delivery gauge. After this setting is made, inspect the delivery pressure gauge to make certain that the gas regulator is providing a constant and stable output pressure.

►Check the system for leaks by closing the downstream equipment valve, setting regulator pressure, closing the cylinder valve and turning the regulator adjusting knob one turn counterclockwise. A decrease in the high-pressure gauge will indicate a leak in the fitting where the valve connects to the cylinder or high-pressure gauge. A decrease in the low pressure gauge indicates a leak in the outlet fitting, low pressure gauge or a downstream equipment connection. Check for the exact location by using appropriate leak detection instrumentation or methods. A decrease in the high pressure gauge occurring concurrently with an increase in the low pressure gauge indicates a leak in the regulator seat. The regulator must then be repaired or returned to Scott for servicing.

►Close the cylinder valve when the cylinder is not in use. When the downstream equipment is not being used, close the cylinder valve and open the equipment valve to remove all pressure from the regulator. Close the equipment valve and then release all tension on the gas regulator adjusting knob by turning it in the full counterclockwise direction.

4. Removing a Regulator from Service

Close the cylinder valve fully and isolate the regulator by safely removing all gas from it. Consideration must be given to the type of gas in service and the safe removal of residual gas from the regulator or equipment. With no gas pressure in the regulator, remove all tension on the regulator adjusting knob by turning it in the full counterclockwise direction. Remove the regulator from the cylinder by using the proper wrench and protect it from damage and foreign materials. Install the protection cap on the cylinder valve.