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Baker Hughes
© 2020 Baker Hughes Company. All rights reserved.
A. General Requirements
The safety valve shall be connected to the boiler in a vertical position independent
of any other steam connection, and attached as close as possible to the boiler.
Intervening pipe or fittings shall be no longer than the face-to-face dimension
of the corresponding tee fitting of the same diameter and pressure under the
corresponding American Standard as set forth by the ASME.
Thoroughly clean the inlet of the valve before installation and be sure that the
proper gasket is used. Tighten bolts evenly. Care should be taken when fastening
bolts on cast iron flanges as cracking may result.
The valve shall be free from external stresses transmitted from the discharge
piping. Figure 5 illustrates a recommended design allowing for ample clearance
to take care of thermal expansion. The riser pipe should be large enough to
accommodate the full capacity of the valve without causing steam to escape by
flowing backward through the drip pan. In no case should the pipe connected to the
valve be of a smaller size than the valve outlet.
When a safety valve is installed on an outdoor unit, it is
advisable to insulate the valve body, including the inlet
flange, up to the bottom of the yoke. The insulation
will stabilize the valve body temperature preventing
variation in the set pressure.
Valves must be readjusted if insulation is installed.
Weather shielding should be used to protect the spring
and to minimize rain or snow from entering the valve
body.
Know all valve exhaust/
leakage points to
avoid possible severe
personal injury or death.
Riser supported
overhead
Drain Pipe Open
To Safe Place
1/
2” -
NPT Drain Pipe
Open to Safe Place (Valves
manufactured prior to 1987
may have other size drain
holes)
Make short as possible
3/4” std. pipe &
fittings
Figure 5: Recommended Installation for Discharge and Vent Piping
IX. Recommended Installation Practices
B. Outdoor Safety Valve Installation
