What general maintenance should be performed on a regulator and how often?
David Gailey
A regulator (or changeover manifold) can last several years if properly maintained. Regulator maintenance is an important part of maximizing your system performance and extending the service life of your system components.
A maintenance schedule is the frequency by which recommended maintenance operations should be performed. Adherence to this maintenance schedule will result in minimizing downtime due to regulator failure, as well as enhancing safety of one's work area. Regulator service defines the gas service in which the regulator is installed in terms of its corrosive nature. The three primary categories are noncorrosive, mildly corrosive, and corrosive.
RECOMMENDED SCHEDULE FOR REGULATORS AND CHANGEOVERS
NONCORROSIVE
EQUIPMENT
Perform leak test and functional test at start-up and once per month for the
first 1-2 years. Increase frequency of tests to 2x per month for equipment 2-5
years old. After 5 years, consider equipment refurbishment or replacement
depending of conditions and frequency of use (per CGA E-15).
MILDLY
CORROSIVE EQUIPMENT
Perform leak test and functional test at start-up and 2x per month for the
first 12 months. Perform source gas or inert gas purge at every shutdown for
the life of the equipment. This prevents moisture from forming corrosive
compounds inside wetted areas.
CORROSIVE/REACTIVE
EQUIPMENT
Perform inert gas purge at every start-up AND shutdown. This prevents moisture
from forming corrosive compounds inside wetted areas and increases the life of
the equipment. Perform leak and *functional tests at every startup to ensure
excess pressures do not create a hazardous environment.
*Many corrosive/reactive regulators and changeovers will need to be housed in a properly designed gas cabinet. Contact Harris Technical Service if you have questions regarding these applications.
RECOMMENDED SCHEDULE FOR REGULATORS AND CHANGEOVERS
MAINTENANCE CHECKS
FUNCTION
TEST
Check the regulator's function. Do this by confirming delivery pressure
increases* when the adjusting knob is turned clockwise and decreases** when
turned counter-clockwise.
*Increase test is best done under static conditions - gas not
flowing - for best results.
**Decrease test must be used with the gas flowing. This test cannot be done
under static conditions.
INERT PURGE
To increase regulator life perform an inert purge on regulators that are used
with corrosive or reactive gases after each use.
LEAK TEST
Here we want to check for an internal (seat) leak in the regulator.
SUGGESTED
METHOD:
Close regulator by adjusting counterclockwise until stop is reached, or the
adjusting knob/key is loose with no tension. Ensure there is a downstream valve
which is closed so that no gas goes downstream of the regulator. Apply pressure
to the inlet. Adjust regulator pressure to the rated delivery pressure. Let
stand for 2-5 minutes, observing any increase in the delivery pressure. If
delivery pressure is steady with no increase, the regulator valve is working
properly.
The Harris Products Group manufactures our regulators in the USA and some have up to 7-year warranties. Keep your regulators regularly maintained.