MCDonald 6282 Instructions

NOTE: Failure to follow this procedure may result in interrupted gas service and loss of pilot lights.
NOTE: It is recommended that a manometer be installed at the downstream pressure tap prior to operating
the bypass. The manometer will monitor the downstream pressure. In the event the pressure drops
below your stated system requirements, an improper sequence may have occurred. The valves should be
returned to normal operation immediately to restore flow of gas. Once pressure is restored, the bypass
procedure can then be started again. If the pressure drops below your stated system requirements at
any time, pilots need to be checked and possibly relit.
- Bypass application only at regulated pressure.
- Follow all applicable codes and procedures.

Normal Operating Flow Mode

Inlet valve at position 3 (arrow pointing down),
outlet valve at position 4 (arrow pointing right).

Bypass Flow Mode

Turn outlet valve 90º counter clockwise to Position 1.

Meter Maintenance

Turn inlet valve 90º counter clockwise to Position 2.
Meter Maintenance
Perform required maintenance to the meter, when the meter change out or meter maintenance has been completed, purge the air out of the new meter (as
noted in Step 4 below) before taking the meter bar out of bypass mode. Do this by fully assembling the meter to the bar, then removing the purge port plug
to allow gas to flow to atmosphere. Reference figure above for purge port location. Once the plug has been removed, proceed to step 4.

Purge Mode

Slowly turn the inlet valve 90º clockwise to position 3. This means
that gas is now starting to enter the meter and will push the air in
the meter to the purge port where it can escape to atmosphere. Purge
meter until the smallest increment dial makes two full rotations. DO
NOT PURGE IN A CONFINED SPACE! Once the meter is purged, replace
the purge port plug.

Back To Normal Operation Flow Mode

Turn the outlet valve 90º clockwise to Position 4.
3210-625
Natural Gas
6282 By-Pass Procedure
800.292.2737 | sales@aymcdonald.com | aymcdonald.com
2
3
Inlet
Valve
1
2
3
INLET OUTLET
1
2
3
1
2
3
1
2
3
1
4
2
3
Manometer Pressure
Gauge Tap
Outlet
Valve
1
4
Purge
Port
4
4
4
By-Pass Mode
4
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